Files
scylla/service/storage_service.cc
Petr Gusev 5a1418fdba token_metadata: get_endpoint_for_host_id -> get_endpoint_for_host_id_if_known
This commit fixes an inconsistency in method names:
get_host_id and get_host_id_if_known are
(internal_error, returns null), but there was only
one method for the opposite conversion - get_endpoint_for_host_id,
and it returns null. In this commit we change it to on_internal_error
if it can't find the argument and add another method
get_endpoint_for_host_id_if_known which returns null in this case.

We can't use get_endpoint_for_host_id/get_host_id
in host_id_or_endpoint::resolve since it's called
from storage_service::parse_node_list
-> token_metadata::parse_host_id_and_endpoint,
and exceptions are caught and handled in
`storage_service::parse_node_list`.
2023-12-11 12:51:34 +04:00

7626 lines
376 KiB
C++

/*
*
* Modified by ScyllaDB
* Copyright (C) 2015-present ScyllaDB
*
*/
/*
* SPDX-License-Identifier: (AGPL-3.0-or-later and Apache-2.0)
*/
#include "storage_service.hh"
#include "service/topology_guard.hh"
#include "service/session.hh"
#include "dht/boot_strapper.hh"
#include <seastar/core/distributed.hh>
#include <seastar/util/defer.hh>
#include <seastar/coroutine/as_future.hh>
#include "gms/endpoint_state.hh"
#include "locator/snitch_base.hh"
#include "locator/production_snitch_base.hh"
#include "db/system_keyspace.hh"
#include "db/system_distributed_keyspace.hh"
#include "db/consistency_level.hh"
#include "service/tablet_allocator.hh"
#include "locator/tablets.hh"
#include "locator/tablet_metadata_guard.hh"
#include "replica/tablet_mutation_builder.hh"
#include <seastar/core/smp.hh>
#include "mutation/canonical_mutation.hh"
#include "seastar/core/on_internal_error.hh"
#include "seastar/core/scollectd.hh"
#include "service/raft/group0_state_machine.hh"
#include "service/raft/raft_group0_client.hh"
#include "utils/UUID.hh"
#include "gms/inet_address.hh"
#include "locator/load_sketch.hh"
#include "log.hh"
#include "service/migration_manager.hh"
#include "service/raft/raft_group0.hh"
#include "utils/to_string.hh"
#include "gms/gossiper.hh"
#include "gms/feature_service.hh"
#include <seastar/core/thread.hh>
#include <sstream>
#include <algorithm>
#include "locator/local_strategy.hh"
#include "version.hh"
#include "unimplemented.hh"
#include "streaming/stream_plan.hh"
#include "streaming/stream_state.hh"
#include "dht/range_streamer.hh"
#include <boost/range/adaptors.hpp>
#include <boost/range/algorithm.hpp>
#include "service/load_broadcaster.hh"
#include "transport/server.hh"
#include <seastar/core/rwlock.hh>
#include "db/batchlog_manager.hh"
#include "db/commitlog/commitlog.hh"
#include "db/hints/manager.hh"
#include "utils/exceptions.hh"
#include "message/messaging_service.hh"
#include "supervisor.hh"
#include "compaction/compaction_manager.hh"
#include "sstables/sstables.hh"
#include "db/config.hh"
#include "db/schema_tables.hh"
#include "replica/database.hh"
#include "replica/tablets.hh"
#include <seastar/core/metrics.hh>
#include "cdc/generation.hh"
#include "cdc/generation_service.hh"
#include "repair/repair.hh"
#include "repair/row_level.hh"
#include "gms/generation-number.hh"
#include <seastar/core/coroutine.hh>
#include <seastar/coroutine/maybe_yield.hh>
#include <seastar/coroutine/parallel_for_each.hh>
#include <seastar/coroutine/as_future.hh>
#include <seastar/coroutine/exception.hh>
#include "utils/stall_free.hh"
#include "utils/error_injection.hh"
#include "locator/util.hh"
#include "idl/storage_service.dist.hh"
#include "service/storage_proxy.hh"
#include "service/raft/raft_address_map.hh"
#include "service/raft/join_node.hh"
#include "idl/join_node.dist.hh"
#include "protocol_server.hh"
#include "types/set.hh"
#include "node_ops/node_ops_ctl.hh"
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/join.hpp>
using token = dht::token;
using UUID = utils::UUID;
using inet_address = gms::inet_address;
extern logging::logger cdc_log;
namespace db {
extern thread_local data_type cdc_generation_ts_id_type;
}
namespace service {
static logging::logger slogger("storage_service");
static thread_local session_manager topology_session_manager;
session_manager& get_topology_session_manager() {
return topology_session_manager;
}
static constexpr std::chrono::seconds wait_for_live_nodes_timeout{30};
storage_service::storage_service(abort_source& abort_source,
distributed<replica::database>& db, gms::gossiper& gossiper,
sharded<db::system_keyspace>& sys_ks,
sharded<db::system_distributed_keyspace>& sys_dist_ks,
gms::feature_service& feature_service,
sharded<service::migration_manager>& mm,
locator::shared_token_metadata& stm,
locator::effective_replication_map_factory& erm_factory,
sharded<netw::messaging_service>& ms,
sharded<repair_service>& repair,
sharded<streaming::stream_manager>& stream_manager,
endpoint_lifecycle_notifier& elc_notif,
sharded<db::batchlog_manager>& bm,
sharded<locator::snitch_ptr>& snitch,
sharded<service::tablet_allocator>& tablet_allocator,
sharded<cdc::generation_service>& cdc_gens,
cql3::query_processor& qp)
: _abort_source(abort_source)
, _feature_service(feature_service)
, _db(db)
, _gossiper(gossiper)
, _messaging(ms)
, _migration_manager(mm)
, _qp(qp)
, _repair(repair)
, _stream_manager(stream_manager)
, _snitch(snitch)
, _group0(nullptr)
, _node_ops_abort_thread(node_ops_abort_thread())
, _shared_token_metadata(stm)
, _erm_factory(erm_factory)
, _lifecycle_notifier(elc_notif)
, _batchlog_manager(bm)
, _sys_ks(sys_ks)
, _sys_dist_ks(sys_dist_ks)
, _snitch_reconfigure([this] {
return container().invoke_on(0, [] (auto& ss) {
return ss.snitch_reconfigured();
});
})
, _tablet_allocator(tablet_allocator)
, _cdc_gens(cdc_gens)
{
register_metrics();
_listeners.emplace_back(make_lw_shared(bs2::scoped_connection(sstable_read_error.connect([this] { do_isolate_on_error(disk_error::regular); }))));
_listeners.emplace_back(make_lw_shared(bs2::scoped_connection(sstable_write_error.connect([this] { do_isolate_on_error(disk_error::regular); }))));
_listeners.emplace_back(make_lw_shared(bs2::scoped_connection(general_disk_error.connect([this] { do_isolate_on_error(disk_error::regular); }))));
_listeners.emplace_back(make_lw_shared(bs2::scoped_connection(commit_error.connect([this] { do_isolate_on_error(disk_error::commit); }))));
if (_snitch.local_is_initialized()) {
_listeners.emplace_back(make_lw_shared(_snitch.local()->when_reconfigured(_snitch_reconfigure)));
}
auto& cfg = _db.local().get_config();
init_messaging_service(cfg.consistent_cluster_management() && cfg.check_experimental(db::experimental_features_t::feature::CONSISTENT_TOPOLOGY_CHANGES));
}
enum class node_external_status {
UNKNOWN = 0,
STARTING = 1,
JOINING = 2,
NORMAL = 3,
LEAVING = 4,
DECOMMISSIONED = 5,
DRAINING = 6,
DRAINED = 7,
MOVING = 8 //deprecated
};
static node_external_status map_operation_mode(storage_service::mode m) {
switch (m) {
case storage_service::mode::NONE: return node_external_status::STARTING;
case storage_service::mode::STARTING: return node_external_status::STARTING;
case storage_service::mode::BOOTSTRAP: return node_external_status::JOINING;
case storage_service::mode::JOINING: return node_external_status::JOINING;
case storage_service::mode::NORMAL: return node_external_status::NORMAL;
case storage_service::mode::LEAVING: return node_external_status::LEAVING;
case storage_service::mode::DECOMMISSIONED: return node_external_status::DECOMMISSIONED;
case storage_service::mode::DRAINING: return node_external_status::DRAINING;
case storage_service::mode::DRAINED: return node_external_status::DRAINED;
case storage_service::mode::MOVING: return node_external_status::MOVING;
}
return node_external_status::UNKNOWN;
}
void storage_service::register_metrics() {
if (this_shard_id() != 0) {
// the relevant data is distributed between the shards,
// We only need to register it once.
return;
}
namespace sm = seastar::metrics;
_metrics.add_group("node", {
sm::make_gauge("operation_mode", sm::description("The operation mode of the current node. UNKNOWN = 0, STARTING = 1, JOINING = 2, NORMAL = 3, "
"LEAVING = 4, DECOMMISSIONED = 5, DRAINING = 6, DRAINED = 7, MOVING = 8"), [this] {
return static_cast<std::underlying_type_t<node_external_status>>(map_operation_mode(_operation_mode));
}),
});
}
bool storage_service::is_replacing() {
const auto& cfg = _db.local().get_config();
if (!cfg.replace_node_first_boot().empty()) {
if (_sys_ks.local().bootstrap_complete()) {
slogger.info("Replace node on first boot requested; this node is already bootstrapped");
return false;
}
return true;
}
if (!cfg.replace_address_first_boot().empty()) {
if (_sys_ks.local().bootstrap_complete()) {
slogger.info("Replace address on first boot requested; this node is already bootstrapped");
return false;
}
return true;
}
// Returning true if cfg.replace_address is provided
// will trigger an exception down the road if bootstrap_complete(),
// as it is an error to use this option post bootstrap.
// That said, we should just stop supporting it and force users
// to move to the new, replace_node_first_boot config option.
return !cfg.replace_address().empty();
}
bool storage_service::is_first_node() {
if (is_replacing()) {
return false;
}
auto seeds = _gossiper.get_seeds();
if (seeds.empty()) {
return false;
}
// Node with the smallest IP address is chosen as the very first node
// in the cluster. The first node is the only node that does not
// bootstrap in the cluster. All other nodes will bootstrap.
std::vector<gms::inet_address> sorted_seeds(seeds.begin(), seeds.end());
std::sort(sorted_seeds.begin(), sorted_seeds.end());
if (sorted_seeds.front() == get_broadcast_address()) {
slogger.info("I am the first node in the cluster. Skip bootstrap. Node={}", get_broadcast_address());
return true;
}
return false;
}
bool storage_service::should_bootstrap() {
return !_sys_ks.local().bootstrap_complete() && !is_first_node();
}
/* Broadcasts the chosen tokens through gossip,
* together with a CDC generation timestamp and STATUS=NORMAL.
*
* Assumes that no other functions modify CDC_GENERATION_ID, TOKENS or STATUS
* in the gossiper's local application state while this function runs.
*/
static future<> set_gossip_tokens(gms::gossiper& g,
const std::unordered_set<dht::token>& tokens, std::optional<cdc::generation_id> cdc_gen_id) {
assert(!tokens.empty());
// Order is important: both the CDC streams timestamp and tokens must be known when a node handles our status.
return g.add_local_application_state({
{ gms::application_state::TOKENS, gms::versioned_value::tokens(tokens) },
{ gms::application_state::CDC_GENERATION_ID, gms::versioned_value::cdc_generation_id(cdc_gen_id) },
{ gms::application_state::STATUS, gms::versioned_value::normal(tokens) }
});
}
/*
* The helper waits for two things
* 1) for schema agreement
* 2) there's no pending node operations
* before proceeding with the bootstrap or replace.
*
* This function must only be called if we're not the first node
* (i.e. booting into existing cluster).
*
* Precondition: gossiper observed at least one other live node;
* see `gossiper::wait_for_live_nodes_to_show_up()`.
*/
future<> storage_service::wait_for_ring_to_settle() {
auto t = gms::gossiper::clk::now();
while (true) {
slogger.info("waiting for schema information to complete");
while (!_migration_manager.local().have_schema_agreement()) {
co_await sleep_abortable(std::chrono::milliseconds(10), _abort_source);
}
co_await update_topology_change_info("joining");
auto tmptr = get_token_metadata_ptr();
if (!_db.local().get_config().consistent_rangemovement() ||
(tmptr->get_bootstrap_tokens().empty() && tmptr->get_leaving_endpoints().empty())) {
break;
}
auto elapsed = std::chrono::duration_cast<std::chrono::seconds>(gms::gossiper::clk::now() - t).count();
slogger.info("Checking bootstrapping/leaving nodes: tokens {}, leaving {}, sleep 1 second and check again ({} seconds elapsed)",
tmptr->get_bootstrap_tokens().size(),
tmptr->get_leaving_endpoints().size(),
elapsed);
if (gms::gossiper::clk::now() > t + std::chrono::seconds(60)) {
throw std::runtime_error("Other bootstrapping/leaving nodes detected, cannot bootstrap while consistent_rangemovement is true");
}
co_await sleep_abortable(std::chrono::seconds(1), _abort_source);
}
slogger.info("Checking bootstrapping/leaving nodes: ok");
}
static locator::node::state to_topology_node_state(node_state ns) {
switch (ns) {
case node_state::bootstrapping: return locator::node::state::bootstrapping;
case node_state::decommissioning: return locator::node::state::being_decommissioned;
case node_state::removing: return locator::node::state::being_removed;
case node_state::normal: return locator::node::state::normal;
case node_state::rollback_to_normal: return locator::node::state::normal;
case node_state::left_token_ring: return locator::node::state::left;
case node_state::left: return locator::node::state::left;
case node_state::replacing: return locator::node::state::replacing;
case node_state::rebuilding: return locator::node::state::normal;
case node_state::none: return locator::node::state::none;
}
on_internal_error(slogger, format("unhandled node state: {}", ns));
}
future<> storage_service::topology_state_load() {
#ifdef SEASTAR_DEBUG
static bool running = false;
assert(!running); // The function is not re-entrant
auto d = defer([] {
running = false;
});
running = true;
#endif
if (!_raft_topology_change_enabled) {
co_return;
}
slogger.debug("raft topology: reload raft topology state");
// read topology state from disk and recreate token_metadata from it
_topology_state_machine._topology = co_await _sys_ks.local().load_topology_state();
co_await _feature_service.container().invoke_on_all([&] (gms::feature_service& fs) {
return fs.enable(boost::copy_range<std::set<std::string_view>>(_topology_state_machine._topology.enabled_features));
});
// Update the legacy `enabled_features` key in `system.scylla_local`.
// It's OK to update it after enabling features because `system.topology` now
// is the source of truth about enabled features.
co_await _sys_ks.local().save_local_enabled_features(_topology_state_machine._topology.enabled_features, false);
const auto& am = _group0->address_map();
auto id2ip = [this, &am] (raft::server_id id) -> future<gms::inet_address> {
auto ip = am.find(id);
while (!ip) {
static logger::rate_limit rate_limit{std::chrono::seconds(1)};
slogger.log(log_level::warn, rate_limit, "raft topology: cannot map {} to ip, retrying.", id);
// FIXME: https://github.com/scylladb/scylladb/issues/12279
// Loop until gossiper figures the address
// but the solution is to change token_metadata to work with server_ids instead of ips
co_await sleep_abortable(std::chrono::milliseconds(5), _abort_source);
ip = am.find(id);
}
co_return *ip;
};
for (const auto& id: _topology_state_machine._topology.left_nodes) {
auto ip = co_await id2ip(id);
if (_gossiper.get_live_members().contains(ip) || _gossiper.get_unreachable_members().contains(ip)) {
co_await remove_endpoint(ip, gms::null_permit_id);
}
// FIXME: when removing a node from the cluster through `removenode`, we should ban it early,
// at the beginning of the removal process (so it doesn't disrupt us in the middle of the process).
// The node is only included in `left_nodes` at the end of the process.
//
// However if we do that, we need to also implement unbanning a node and do it if `removenode` is aborted.
co_await _messaging.local().ban_host(locator::host_id{id.uuid()});
}
co_await mutate_token_metadata(seastar::coroutine::lambda([this, &id2ip, &am] (mutable_token_metadata_ptr tmptr) -> future<> {
co_await tmptr->clear_gently(); // drop previous state
tmptr->set_version(_topology_state_machine._topology.version);
auto update_topology = [&] (locator::host_id id, inet_address ip, const replica_state& rs) {
tmptr->update_topology(ip, locator::endpoint_dc_rack{rs.datacenter, rs.rack},
to_topology_node_state(rs.state), rs.shard_count);
tmptr->update_host_id(id, ip);
};
auto add_normal_node = [&] (raft::server_id id, const replica_state& rs) -> future<> {
locator::host_id host_id{id.uuid()};
auto ip = co_await id2ip(id);
slogger.trace("raft topology: loading topology: raft id={} ip={} node state={} dc={} rack={} tokens state={} tokens={} shards={}",
id, ip, rs.state, rs.datacenter, rs.rack, _topology_state_machine._topology.tstate, rs.ring.value().tokens, rs.shard_count);
// Save tokens, not needed for raft topology management, but needed by legacy
// Also ip -> id mapping is needed for address map recreation on reboot
if (!is_me(ip)) {
// Some state that is used to fill in 'peeers' table is still propagated over gossiper.
// Populate the table with the state from the gossiper here since storage_service::on_change()
// (which is called each time gossiper state changes) may have skipped it because the tokens
// for the node were not in the 'normal' state yet
co_await update_peer_info(ip);
// And then amend with the info from raft
co_await _sys_ks.local().update_tokens(ip, rs.ring.value().tokens);
co_await _sys_ks.local().update_peer_info(ip, "data_center", rs.datacenter);
co_await _sys_ks.local().update_peer_info(ip, "rack", rs.rack);
co_await _sys_ks.local().update_peer_info(ip, "host_id", id.uuid());
co_await _sys_ks.local().update_peer_info(ip, "release_version", rs.release_version);
} else {
co_await _sys_ks.local().update_tokens(rs.ring.value().tokens);
co_await _gossiper.add_local_application_state({{ gms::application_state::STATUS, gms::versioned_value::normal(rs.ring.value().tokens) }});
}
update_topology(host_id, ip, rs);
co_await tmptr->update_normal_tokens(rs.ring.value().tokens, ip);
};
for (const auto& [id, rs]: _topology_state_machine._topology.normal_nodes) {
co_await add_normal_node(id, rs);
}
tmptr->set_read_new(std::invoke([](std::optional<topology::transition_state> state) {
using read_new_t = locator::token_metadata::read_new_t;
if (!state.has_value()) {
return read_new_t::no;
}
switch (*state) {
case topology::transition_state::join_group0:
[[fallthrough]];
case topology::transition_state::tablet_migration:
[[fallthrough]];
case topology::transition_state::commit_cdc_generation:
[[fallthrough]];
case topology::transition_state::tablet_draining:
[[fallthrough]];
case topology::transition_state::write_both_read_old:
return read_new_t::no;
case topology::transition_state::write_both_read_new:
return read_new_t::yes;
}
}, _topology_state_machine._topology.tstate));
for (const auto& [id, rs]: _topology_state_machine._topology.transition_nodes) {
locator::host_id host_id{id.uuid()};
auto ip = co_await id2ip(id);
slogger.trace("raft topology: loading topology: raft id={} ip={} node state={} dc={} rack={} tokens state={} tokens={}",
id, ip, rs.state, rs.datacenter, rs.rack, _topology_state_machine._topology.tstate,
seastar::value_of([&] () -> sstring {
return rs.ring ? ::format("{}", rs.ring->tokens) : sstring("null");
}));
switch (rs.state) {
case node_state::bootstrapping:
if (rs.ring.has_value()) {
if (!is_me(ip)) {
// Save ip -> id mapping in peers table because we need it on restart, but do not save tokens until owned
co_await _sys_ks.local().update_tokens(ip, {});
co_await _sys_ks.local().update_peer_info(ip, "host_id", id.uuid());
}
update_topology(host_id, ip, rs);
if (_topology_state_machine._topology.normal_nodes.empty()) {
// This is the first node in the cluster. Insert the tokens as normal to the token ring early
// so we can perform writes to regular 'distributed' tables during the bootstrap procedure
// (such as the CDC generation write).
// It doesn't break anything to set the tokens to normal early in this single-node case.
co_await tmptr->update_normal_tokens(rs.ring.value().tokens, ip);
} else {
tmptr->add_bootstrap_tokens(rs.ring.value().tokens, ip);
co_await update_topology_change_info(tmptr, ::format("bootstrapping node {}/{}", id, ip));
}
}
break;
case node_state::decommissioning:
case node_state::removing:
update_topology(host_id, ip, rs);
co_await tmptr->update_normal_tokens(rs.ring.value().tokens, ip);
tmptr->add_leaving_endpoint(ip);
co_await update_topology_change_info(tmptr, ::format("{} {}/{}", rs.state, id, ip));
break;
case node_state::replacing: {
if (rs.ring.has_value()) {
assert(_topology_state_machine._topology.req_param.contains(id));
auto replaced_id = std::get<replace_param>(_topology_state_machine._topology.req_param[id]).replaced_id;
auto existing_ip = am.find(replaced_id);
if (!existing_ip) {
// FIXME: What if not known?
on_fatal_internal_error(slogger, ::format("Cannot map id of a node being replaced {} to its ip", replaced_id));
}
assert(existing_ip);
// FIXME: Topology cannot hold two IPs with different host ids yet so
// when replacing we must advertise the replaced_id for the ip, otherwise
// topology will complain about host id of a local node changing and fail.
update_topology(ip == existing_ip ? locator::host_id(replaced_id.uuid()) : host_id, ip, rs);
tmptr->add_replacing_endpoint(*existing_ip, ip);
co_await update_topology_change_info(tmptr, ::format("replacing {}/{} by {}/{}", replaced_id, *existing_ip, id, ip));
}
}
break;
case node_state::rebuilding:
// Rebuilding node is normal
co_await add_normal_node(id, rs);
break;
case node_state::left_token_ring:
break;
case node_state::rollback_to_normal:
// no need for double writes anymore since op failed
co_await add_normal_node(id, rs);
break;
default:
on_fatal_internal_error(slogger, ::format("Unexpected state {} for node {}", rs.state, id));
}
}
if (_db.local().get_config().check_experimental(db::experimental_features_t::feature::TABLETS)) {
tmptr->set_tablets(co_await replica::read_tablet_metadata(_qp));
tmptr->tablets().set_balancing_enabled(_topology_state_machine._topology.tablet_balancing_enabled);
}
}));
co_await update_fence_version(_topology_state_machine._topology.fence_version);
// We don't load gossiper endpoint states in storage_service::join_cluster
// if _raft_topology_change_enabled. On the other hand gossiper is still needed
// even in case of _raft_topology_change_enabled mode, since it still contains part
// of the cluster state. To work correctly, the gossiper needs to know the current
// endpoints. We cannot rely on seeds alone, since it is not guaranteed that seeds
// will be up to date and reachable at the time of restart.
for (const auto& e: get_token_metadata_ptr()->get_all_endpoints()) {
if (!is_me(e) && !_gossiper.get_endpoint_state_ptr(e)) {
co_await _gossiper.add_saved_endpoint(e);
}
}
if (auto gen_id = _topology_state_machine._topology.current_cdc_generation_id) {
slogger.debug("topology_state_load: current CDC generation ID: {}", *gen_id);
co_await _cdc_gens.local().handle_cdc_generation(*gen_id);
}
}
future<> storage_service::topology_transition() {
assert(this_shard_id() == 0);
co_await topology_state_load(); // reload new state
_topology_state_machine.event.broadcast();
}
future<> storage_service::merge_topology_snapshot(raft_topology_snapshot snp) {
std::vector<mutation> muts;
muts.reserve(snp.topology_mutations.size() + (snp.cdc_generation_mutations.size()));
{
auto s = _db.local().find_schema(db::system_keyspace::NAME, db::system_keyspace::TOPOLOGY);
boost::transform(snp.topology_mutations, std::back_inserter(muts), [s] (const canonical_mutation& m) {
return m.to_mutation(s);
});
}
if (snp.cdc_generation_mutations.size() > 0) {
auto s = _db.local().find_schema(db::system_keyspace::NAME, db::system_keyspace::CDC_GENERATIONS_V3);
boost::transform(snp.cdc_generation_mutations, std::back_inserter(muts), [s] (const canonical_mutation& m) {
return m.to_mutation(s);
});
}
co_await _db.local().apply(freeze(muts), db::no_timeout);
}
template<typename Builder>
class topology_mutation_builder_base {
private:
Builder& self() {
return *static_cast<Builder*>(this);
}
protected:
enum class collection_apply_mode {
overwrite,
update,
};
using builder_base = topology_mutation_builder_base<Builder>;
Builder& apply_atomic(const char* cell, const data_value& value);
template<std::ranges::range C>
requires std::convertible_to<std::ranges::range_value_t<C>, data_value>
Builder& apply_set(const char* cell, collection_apply_mode apply_mode, const C& c);
Builder& del(const char* cell);
};
class topology_mutation_builder;
class topology_node_mutation_builder
: public topology_mutation_builder_base<topology_node_mutation_builder> {
friend builder_base;
topology_mutation_builder& _builder;
deletable_row& _r;
private:
row& row();
api::timestamp_type timestamp() const;
const schema& schema() const;
public:
topology_node_mutation_builder(topology_mutation_builder&, raft::server_id);
topology_node_mutation_builder& set(const char* cell, node_state value);
topology_node_mutation_builder& set(const char* cell, topology_request value);
topology_node_mutation_builder& set(const char* cell, const sstring& value);
topology_node_mutation_builder& set(const char* cell, const raft::server_id& value);
topology_node_mutation_builder& set(const char* cell, const std::unordered_set<raft::server_id>& nodes_ids);
topology_node_mutation_builder& set(const char* cell, const std::unordered_set<dht::token>& value);
template<typename S>
requires std::constructible_from<sstring, S>
topology_node_mutation_builder& set(const char* cell, const std::set<S>& value);
topology_node_mutation_builder& set(const char* cell, const uint32_t& value);
topology_node_mutation_builder& set(const char* cell, const utils::UUID& value);
topology_node_mutation_builder& del(const char* cell);
canonical_mutation build();
};
class topology_mutation_builder
: public topology_mutation_builder_base<topology_mutation_builder> {
friend builder_base;
friend class topology_node_mutation_builder;
schema_ptr _s;
mutation _m;
api::timestamp_type _ts;
std::optional<topology_node_mutation_builder> _node_builder;
private:
row& row();
api::timestamp_type timestamp() const;
const schema& schema() const;
public:
topology_mutation_builder(api::timestamp_type ts);
topology_mutation_builder& set_transition_state(topology::transition_state);
topology_mutation_builder& set_version(topology::version_t);
topology_mutation_builder& set_fence_version(topology::version_t);
topology_mutation_builder& set_session(session_id);
topology_mutation_builder& set_tablet_balancing_enabled(bool);
topology_mutation_builder& set_current_cdc_generation_id(const cdc::generation_id_v2&);
topology_mutation_builder& set_new_cdc_generation_data_uuid(const utils::UUID& value);
topology_mutation_builder& set_unpublished_cdc_generations(const std::vector<cdc::generation_id_v2>& values);
topology_mutation_builder& set_global_topology_request(global_topology_request);
template<typename S>
requires std::constructible_from<sstring, S>
topology_mutation_builder& add_enabled_features(const std::set<S>& value);
topology_mutation_builder& add_unpublished_cdc_generation(const cdc::generation_id_v2& value);
topology_mutation_builder& del_transition_state();
topology_mutation_builder& del_session();
topology_mutation_builder& del_global_topology_request();
topology_node_mutation_builder& with_node(raft::server_id);
canonical_mutation build() { return canonical_mutation{std::move(_m)}; }
};
topology_mutation_builder::topology_mutation_builder(api::timestamp_type ts) :
_s(db::system_keyspace::topology()),
_m(_s, partition_key::from_singular(*_s, db::system_keyspace::TOPOLOGY)),
_ts(ts) {
}
topology_node_mutation_builder::topology_node_mutation_builder(topology_mutation_builder& builder, raft::server_id id) :
_builder(builder),
_r(_builder._m.partition().clustered_row(*_builder._s, clustering_key::from_singular(*_builder._s, id.uuid()))) {
_r.apply(row_marker(_builder._ts));
}
template<typename Builder>
Builder& topology_mutation_builder_base<Builder>::apply_atomic(const char* cell, const data_value& value) {
const column_definition* cdef = self().schema().get_column_definition(cell);
assert(cdef);
self().row().apply(*cdef, atomic_cell::make_live(*cdef->type, self().timestamp(), cdef->type->decompose(value)));
return self();
}
template<typename Builder>
template<std::ranges::range C>
requires std::convertible_to<std::ranges::range_value_t<C>, data_value>
Builder& topology_mutation_builder_base<Builder>::apply_set(const char* cell, collection_apply_mode apply_mode, const C& c) {
const column_definition* cdef = self().schema().get_column_definition(cell);
assert(cdef);
auto vtype = static_pointer_cast<const set_type_impl>(cdef->type)->get_elements_type();
std::set<bytes, serialized_compare> cset(vtype->as_less_comparator());
for (const auto& v : c) {
cset.insert(vtype->decompose(data_value(v)));
}
collection_mutation_description cm;
cm.cells.reserve(cset.size());
for (const bytes& raw : cset) {
cm.cells.emplace_back(raw, atomic_cell::make_live(*bytes_type, self().timestamp(), bytes_view()));
}
if (apply_mode == collection_apply_mode::overwrite) {
cm.tomb = tombstone(self().timestamp() - 1, gc_clock::now());
}
self().row().apply(*cdef, cm.serialize(*cdef->type));
return self();
}
template<typename Builder>
Builder& topology_mutation_builder_base<Builder>::del(const char* cell) {
auto cdef = self().schema().get_column_definition(cell);
assert(cdef);
if (!cdef->type->is_multi_cell()) {
self().row().apply(*cdef, atomic_cell::make_dead(self().timestamp(), gc_clock::now()));
} else {
collection_mutation_description cm;
cm.tomb = tombstone{self().timestamp(), gc_clock::now()};
self().row().apply(*cdef, cm.serialize(*cdef->type));
}
return self();
}
row& topology_node_mutation_builder::row() {
return _r.cells();
}
api::timestamp_type topology_node_mutation_builder::timestamp() const {
return _builder._ts;
}
const schema& topology_node_mutation_builder::schema() const {
return *_builder._s;
}
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, node_state value) {
return apply_atomic(cell, sstring{::format("{}", value)});
}
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, topology_request value) {
return apply_atomic(cell, sstring{::format("{}", value)});
}
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, const sstring& value) {
return apply_atomic(cell, value);
}
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, const raft::server_id& value) {
return apply_atomic(cell, value.uuid());
}
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, const uint32_t& value) {
return apply_atomic(cell, int32_t(value));
}
topology_node_mutation_builder& topology_node_mutation_builder::set(
const char* cell, const utils::UUID& value) {
return apply_atomic(cell, value);
}
topology_node_mutation_builder& topology_node_mutation_builder::del(const char* cell) {
return builder_base::del(cell);
}
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, const std::unordered_set<raft::server_id>& nodes_ids) {
return apply_set(cell, collection_apply_mode::overwrite, nodes_ids | boost::adaptors::transformed([] (const auto& node_id) { return node_id.id; }));
}
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, const std::unordered_set<dht::token>& tokens) {
return apply_set(cell, collection_apply_mode::overwrite, tokens | boost::adaptors::transformed([] (const auto& t) { return t.to_sstring(); }));
}
template<typename S>
requires std::constructible_from<sstring, S>
topology_node_mutation_builder& topology_node_mutation_builder::set(const char* cell, const std::set<S>& features) {
return apply_set(cell, collection_apply_mode::overwrite, features | boost::adaptors::transformed([] (const auto& f) { return sstring(f); }));
}
canonical_mutation topology_node_mutation_builder::build() {
return canonical_mutation{std::move(_builder._m)};
}
row& topology_mutation_builder::row() {
return _m.partition().static_row().maybe_create();
}
api::timestamp_type topology_mutation_builder::timestamp() const {
return _ts;
}
const schema& topology_mutation_builder::schema() const {
return *_s;
}
topology_mutation_builder& topology_mutation_builder::set_transition_state(topology::transition_state value) {
return apply_atomic("transition_state", ::format("{}", value));
}
topology_mutation_builder& topology_mutation_builder::set_version(topology::version_t value) {
_m.set_static_cell("version", value, _ts);
return *this;
}
topology_mutation_builder& topology_mutation_builder::set_fence_version(topology::version_t value) {
_m.set_static_cell("fence_version", value, _ts);
return *this;
}
topology_mutation_builder& topology_mutation_builder::set_session(session_id value) {
_m.set_static_cell("session", value.uuid(), _ts);
return *this;
}
topology_mutation_builder& topology_mutation_builder::set_tablet_balancing_enabled(bool value) {
_m.set_static_cell("tablet_balancing_enabled", value, _ts);
return *this;
}
topology_mutation_builder& topology_mutation_builder::del_transition_state() {
return del("transition_state");
}
topology_mutation_builder& topology_mutation_builder::del_session() {
return del("session");
}
topology_mutation_builder& topology_mutation_builder::set_current_cdc_generation_id(
const cdc::generation_id_v2& value) {
apply_atomic("current_cdc_generation_timestamp", value.ts);
apply_atomic("current_cdc_generation_uuid", value.id);
return *this;
}
topology_mutation_builder& topology_mutation_builder::set_new_cdc_generation_data_uuid(
const utils::UUID& value) {
return apply_atomic("new_cdc_generation_data_uuid", value);
}
topology_mutation_builder& topology_mutation_builder::set_unpublished_cdc_generations(const std::vector<cdc::generation_id_v2>& values) {
auto dv = values | boost::adaptors::transformed([&] (const auto& v) {
return make_tuple_value(db::cdc_generation_ts_id_type, tuple_type_impl::native_type({v.ts, timeuuid_native_type{v.id}}));
});
return apply_set("unpublished_cdc_generations", collection_apply_mode::overwrite, std::move(dv));
}
topology_mutation_builder& topology_mutation_builder::set_global_topology_request(global_topology_request value) {
return apply_atomic("global_topology_request", ::format("{}", value));
}
template<typename S>
requires std::constructible_from<sstring, S>
topology_mutation_builder& topology_mutation_builder::add_enabled_features(const std::set<S>& features) {
return apply_set("enabled_features", collection_apply_mode::update, features | boost::adaptors::transformed([] (const auto& f) { return sstring(f); }));
}
topology_mutation_builder& topology_mutation_builder::add_unpublished_cdc_generation(const cdc::generation_id_v2& value) {
auto dv = make_tuple_value(db::cdc_generation_ts_id_type, tuple_type_impl::native_type({value.ts, timeuuid_native_type{value.id}}));
return apply_set("unpublished_cdc_generations", collection_apply_mode::update, std::vector<data_value>{std::move(dv)});
}
topology_mutation_builder& topology_mutation_builder::del_global_topology_request() {
return del("global_topology_request");
}
topology_node_mutation_builder& topology_mutation_builder::with_node(raft::server_id n) {
_node_builder.emplace(*this, n);
return *_node_builder;
}
using raft_topology_cmd_handler_type = noncopyable_function<future<raft_topology_cmd_result>(
raft::term_t, uint64_t, const raft_topology_cmd&)>;
class topology_coordinator {
sharded<db::system_distributed_keyspace>& _sys_dist_ks;
gms::gossiper& _gossiper;
netw::messaging_service& _messaging;
locator::shared_token_metadata& _shared_tm;
db::system_keyspace& _sys_ks;
replica::database& _db;
service::raft_group0& _group0;
const service::raft_address_map& _address_map;
service::topology_state_machine& _topo_sm;
abort_source& _as;
raft::server& _raft;
const raft::term_t _term;
uint64_t _last_cmd_index = 0;
raft_topology_cmd_handler_type _raft_topology_cmd_handler;
tablet_allocator& _tablet_allocator;
std::chrono::milliseconds _ring_delay;
using drop_guard_and_retake = bool_class<class retake_guard_tag>;
// True if an ongoing topology change should be rolled back
bool _rollback = false;
const locator::token_metadata& get_token_metadata() const noexcept {
return *_shared_tm.get();
}
locator::token_metadata_ptr get_token_metadata_ptr() const noexcept {
return _shared_tm.get();
}
// This is a topology snapshot for a given node. It contains pointers into the topology state machine
// that may be outdated after guard is released so the structure is meant to be destroyed together
// with the guard
struct node_to_work_on {
group0_guard guard;
const topology_state_machine::topology_type* topology;
raft::server_id id;
const replica_state* rs;
std::optional<topology_request> request;
std::optional<request_param> req_param;
};
// The topology coordinator takes guard before operation start, but it releases it during various
// RPC commands that it sends to make it possible to submit new requests to the state machine while
// the coordinator drives current topology change. It is safe to do so since only the coordinator is
// ever allowed to change node's state, others may only create requests. To make sure the coordinator did
// not change while the lock was released, and hence the old coordinator does not work on old state, we check
// that the raft term is still the same after the lock is re-acquired. Throw term_changed_error if it did.
struct term_changed_error {};
future<> cleanup_group0_config_if_needed() {
auto& topo = _topo_sm._topology;
auto rconf = _group0.group0_server().get_configuration();
if (!rconf.is_joint()) {
// Find nodes that 'left' but still in the config and remove them
auto to_remove = boost::copy_range<std::vector<raft::server_id>>(
rconf.current
| boost::adaptors::transformed([&] (const raft::config_member& m) { return m.addr.id; })
| boost::adaptors::filtered([&] (const raft::server_id& id) { return topo.left_nodes.contains(id); }));
if (!to_remove.empty()) {
// Remove from group 0 nodes that left. They may failed to do so by themselves
try {
slogger.trace("raft topology: topology coordinator fiber removing {}"
" from raft since they are in `left` state", to_remove);
co_await _group0.group0_server().modify_config({}, to_remove, &_as);
} catch (const raft::commit_status_unknown&) {
slogger.trace("raft topology: topology coordinator fiber got unknown status"
" while removing {} from raft", to_remove);
}
}
}
}
// Returns the guard back if no node to work on is found.
std::variant<group0_guard, node_to_work_on> get_node_to_work_on_opt(group0_guard guard) {
auto& topo = _topo_sm._topology;
const std::pair<const raft::server_id, replica_state>* e = nullptr;
std::optional<topology_request> req;
if (topo.transition_nodes.size() != 0) {
// If there is a node that is the middle of topology operation continue with it
e = &*topo.transition_nodes.begin();
} else if (topo.new_nodes.size() != 0) {
// Otherwise check if there is a new node that wants to be joined
e = &*topo.new_nodes.begin();
req = topo.requests[e->first];
} else if (!topo.requests.empty()) {
// If there is no new node but request queue is not empty there is a request for normal node
req = topo.requests.begin()->second;
e = &*topo.normal_nodes.find(topo.requests.begin()->first);
}
if (!e) {
return guard;
}
std::optional<request_param> req_param;
auto rit = topo.req_param.find(e->first);
if (rit != topo.req_param.end()) {
req_param = rit->second;
}
return node_to_work_on{std::move(guard), &topo, e->first, &e->second, std::move(req), std::move(req_param)};
};
node_to_work_on get_node_to_work_on(group0_guard guard) {
auto node_or_guard = get_node_to_work_on_opt(std::move(guard));
if (auto* node = std::get_if<node_to_work_on>(&node_or_guard)) {
return std::move(*node);
}
on_internal_error(slogger, ::format(
"raft topology: could not find node to work on"
" even though the state requires it (state: {})", _topo_sm._topology.tstate));
};
future<group0_guard> start_operation() {
auto guard = co_await _group0.client().start_operation(&_as);
if (_term != _raft.get_current_term()) {
throw term_changed_error{};
}
co_return std::move(guard);
}
void release_node(std::optional<node_to_work_on> node) {
// Leaving the scope destroys the object and releases the guard.
}
node_to_work_on retake_node(group0_guard guard, raft::server_id id) {
auto& topo = _topo_sm._topology;
auto it = topo.find(id);
assert(it);
std::optional<topology_request> req;
auto rit = topo.requests.find(id);
if (rit != topo.requests.end()) {
req = rit->second;
}
std::optional<request_param> req_param;
auto pit = topo.req_param.find(id);
if (pit != topo.req_param.end()) {
req_param = pit->second;
}
return node_to_work_on{std::move(guard), &topo, id, &it->second, std::move(req), std::move(req_param)};
}
group0_guard take_guard(node_to_work_on&& node) {
return std::move(node.guard);
}
future<> update_topology_state(
group0_guard guard, std::vector<canonical_mutation>&& updates, const sstring& reason) {
try {
slogger.trace("raft topology: do update {} reason {}", updates, reason);
topology_change change{std::move(updates)};
group0_command g0_cmd = _group0.client().prepare_command(std::move(change), guard, reason);
co_await _group0.client().add_entry(std::move(g0_cmd), std::move(guard));
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: race while changing state: {}. Retrying", reason);
throw;
}
};
raft::server_id parse_replaced_node(const node_to_work_on& node) {
if (node.req_param) {
auto *param = std::get_if<replace_param>(&*node.req_param);
if (param) {
return param->replaced_id;
}
}
return {};
}
std::unordered_set<raft::server_id> parse_ignore_nodes(const node_to_work_on& node) {
if (node.req_param) {
auto* remove_param = std::get_if<removenode_param>(&*node.req_param);
if (remove_param) {
return remove_param->ignored_ids;
}
auto* rep_param = std::get_if<replace_param>(&*node.req_param);
if (rep_param) {
return rep_param->ignored_ids;
}
}
return {};
}
inet_address id2ip(locator::host_id id) {
auto ip = _address_map.find(raft::server_id(id.uuid()));
if (!ip) {
throw std::runtime_error(::format("no ip address mapping for {}", id));
}
return *ip;
}
future<> exec_direct_command_helper(raft::server_id id, uint64_t cmd_index, const raft_topology_cmd& cmd) {
auto ip = _address_map.find(id);
if (!ip) {
slogger.warn("raft topology: cannot send command {} with term {} and index {} "
"to {} because mapping to ip is not available",
cmd.cmd, _term, cmd_index, id);
co_await coroutine::exception(std::make_exception_ptr(
std::runtime_error(::format("no ip address mapping for {}", id))));
}
slogger.trace("raft topology: send {} command with term {} and index {} to {}/{}",
cmd.cmd, _term, cmd_index, id, *ip);
auto result = _db.get_token_metadata().get_topology().is_me(*ip) ?
co_await _raft_topology_cmd_handler(_term, cmd_index, cmd) :
co_await ser::storage_service_rpc_verbs::send_raft_topology_cmd(
&_messaging, netw::msg_addr{*ip}, id, _term, cmd_index, cmd);
if (result.status == raft_topology_cmd_result::command_status::fail) {
co_await coroutine::exception(std::make_exception_ptr(
std::runtime_error(::format("failed status returned from {}/{}", id, *ip))));
}
};
future<node_to_work_on> exec_direct_command(node_to_work_on&& node, const raft_topology_cmd& cmd) {
auto id = node.id;
release_node(std::move(node));
const auto cmd_index = ++_last_cmd_index;
co_await exec_direct_command_helper(id, cmd_index, cmd);
co_return retake_node(co_await start_operation(), id);
};
future<> exec_global_command_helper(auto nodes, const raft_topology_cmd& cmd) {
const auto cmd_index = ++_last_cmd_index;
auto f = co_await coroutine::as_future(
seastar::parallel_for_each(std::move(nodes), [this, &cmd, cmd_index] (raft::server_id id) {
return exec_direct_command_helper(id, cmd_index, cmd);
}));
if (f.failed()) {
co_await coroutine::return_exception(std::runtime_error(
::format("raft topology: exec_global_command({}) failed with {}",
cmd.cmd, f.get_exception())));
}
};
future<group0_guard> exec_global_command(
group0_guard guard, const raft_topology_cmd& cmd,
const std::unordered_set<raft::server_id>& exclude_nodes,
drop_guard_and_retake drop_and_retake = drop_guard_and_retake::yes) {
auto nodes = _topo_sm._topology.normal_nodes | boost::adaptors::filtered(
[&exclude_nodes] (const std::pair<const raft::server_id, replica_state>& n) {
return std::none_of(exclude_nodes.begin(), exclude_nodes.end(),
[&n] (const raft::server_id& m) { return n.first == m; });
}) | boost::adaptors::map_keys;
if (drop_and_retake) {
release_guard(std::move(guard));
}
co_await exec_global_command_helper(std::move(nodes), cmd);
if (drop_and_retake) {
guard = co_await start_operation();
}
co_return guard;
}
std::unordered_set<raft::server_id> get_excluded_nodes(const node_to_work_on& node) {
auto exclude_nodes = parse_ignore_nodes(node);
exclude_nodes.insert(parse_replaced_node(node));
if (node.request && *node.request == topology_request::remove) {
exclude_nodes.insert(node.id);
}
return exclude_nodes;
}
future<node_to_work_on> exec_global_command(node_to_work_on&& node, const raft_topology_cmd& cmd) {
auto guard = co_await exec_global_command(std::move(node.guard), cmd, get_excluded_nodes(node), drop_guard_and_retake::yes);
co_return retake_node(std::move(guard), node.id);
};
future<> remove_from_group0(const raft::server_id& id) {
slogger.info("raft topology: removing node {} from group 0 configuration...", id);
co_await _group0.remove_from_raft_config(id);
slogger.info("raft topology: node {} removed from group 0 configuration", id);
}
future<> step_down_as_nonvoter() {
// Become a nonvoter which triggers a leader stepdown.
co_await _group0.become_nonvoter();
if (_raft.is_leader()) {
co_await _raft.wait_for_state_change(&_as);
}
// throw term_changed_error so we leave the coordinator loop instead of trying another
// read_barrier which may fail with an (harmless, but unnecessary and annoying) error
// telling us we're not in the configuration anymore (we'll get removed by the new
// coordinator)
throw term_changed_error{};
}
struct bootstrapping_info {
const std::unordered_set<token>& bootstrap_tokens;
const replica_state& rs;
};
// Returns data for a new CDC generation in the form of mutations for the CDC_GENERATIONS_V3 table
// and the generation's UUID.
//
// If there's a bootstrapping node, its tokens should be included in the new generation.
// Pass them and a reference to the bootstrapping node's replica_state through `binfo`.
future<std::pair<utils::UUID, utils::chunked_vector<mutation>>> prepare_new_cdc_generation_data(
locator::token_metadata_ptr tmptr, const group0_guard& guard, std::optional<bootstrapping_info> binfo) {
auto get_sharding_info = [&] (dht::token end) -> std::pair<size_t, uint8_t> {
if (binfo && binfo->bootstrap_tokens.contains(end)) {
return {binfo->rs.shard_count, binfo->rs.ignore_msb};
} else {
// FIXME: token metadata should directly return host ID for given token. See #12279
auto ep = tmptr->get_endpoint(end);
if (!ep) {
// get_sharding_info is only called for bootstrap tokens
// or for tokens present in token_metadata
on_internal_error(slogger, ::format(
"raft topology: make_new_cdc_generation_data: get_sharding_info:"
" can't find endpoint for token {}", end));
}
auto id = tmptr->get_host_id_if_known(*ep);
if (!id) {
on_internal_error(slogger, ::format(
"raft topology: make_new_cdc_generation_data: get_sharding_info:"
" can't find host ID for endpoint {}, owner of token {}", *ep, end));
}
auto ptr = _topo_sm._topology.find(raft::server_id{id->uuid()});
if (!ptr) {
on_internal_error(slogger, ::format(
"raft topology: make_new_cdc_generation_data: get_sharding_info:"
" couldn't find node {} in topology, owner of token {}", *id, end));
}
auto& rs = ptr->second;
return {rs.shard_count, rs.ignore_msb};
}
};
auto gen_uuid = guard.new_group0_state_id();
auto gen_desc = cdc::make_new_generation_description(
binfo ? binfo->bootstrap_tokens : std::unordered_set<token>{}, get_sharding_info, tmptr);
auto gen_table_schema = _db.find_schema(
db::system_keyspace::NAME, db::system_keyspace::CDC_GENERATIONS_V3);
const size_t max_command_size = _raft.max_command_size();
const size_t mutation_size_threshold = max_command_size / 2;
auto gen_mutations = co_await cdc::get_cdc_generation_mutations_v3(
gen_table_schema, gen_uuid, gen_desc, mutation_size_threshold, guard.write_timestamp());
co_return std::pair{gen_uuid, std::move(gen_mutations)};
}
// Broadcasts all mutations returned from `prepare_new_cdc_generation_data` except the last one.
// Each mutation is sent in separate raft command. It takes `group0_guard`, and if the number of mutations
// is greater than one, the guard is dropped, and a new one is created and returned, otherwise the old one
// will be returned. Commands are sent in parallel and unguarded (the guard used for sending the last mutation
// will guarantee that the term hasn't been changed). Returns the generation's UUID, guard and last mutation,
// which will be sent with additional topology data by the caller.
//
// If we send the last mutation in the `write_mutation` command, we would use a total of `n + 1` commands
// instead of `n-1 + 1` (where `n` is the number of mutations), so it's better to send it in `topology_change`
// (we need to send it after all `write_mutations`) with some small metadata.
//
// With the default commitlog segment size, `mutation_size_threshold` will be 4 MB. In large clusters e.g.
// 100 nodes, 64 shards per node, 256 vnodes cdc generation data can reach the size of 30 MB, thus
// there will be no more than 8 commands.
//
// In a multi-DC cluster with 100ms latencies between DCs, this operation should take about 200ms since we
// send the commands concurrently, but even if the commands were replicated sequentially by Raft,
// it should take no more than 1.6s which is incomparably smaller than bootstrapping operation
// (bootstrapping is quick if there is no data in the cluster, but usually if one has 100 nodes they
// have tons of data, so indeed streaming/repair will take much longer (hours/days)).
future<std::tuple<utils::UUID, group0_guard, canonical_mutation>> prepare_and_broadcast_cdc_generation_data(
locator::token_metadata_ptr tmptr, group0_guard guard, std::optional<bootstrapping_info> binfo) {
auto [gen_uuid, gen_mutations] = co_await prepare_new_cdc_generation_data(tmptr, guard, binfo);
if (gen_mutations.empty()) {
on_internal_error(slogger, "cdc_generation_data: gen_mutations is empty");
}
std::vector<canonical_mutation> updates{gen_mutations.begin(), gen_mutations.end()};
if (updates.size() > 1) {
release_guard(std::move(guard));
co_await parallel_for_each(updates.begin(), std::prev(updates.end()), [this, gen_uuid = gen_uuid] (canonical_mutation& m) {
auto const reason = format(
"insert CDC generation data (UUID: {}), part", gen_uuid);
slogger.trace("raft topology: do update {} reason {}", m, reason);
write_mutations change{{std::move(m)}};
group0_command g0_cmd = _group0.client().prepare_command(std::move(change), reason);
return _group0.client().add_entry_unguarded(std::move(g0_cmd));
});
guard = co_await start_operation();
}
co_return std::tuple{gen_uuid, std::move(guard), std::move(updates.back())};
}
// Deletes obsolete CDC generations if there is a clean-up candidate and it can be safely removed.
//
// Appends necessary mutations to `updates` and updates the `reason` string.
future<> clean_obsolete_cdc_generations(
const group0_guard& guard,
std::vector<canonical_mutation>& updates,
sstring& reason) {
auto candidate = co_await _sys_ks.get_cdc_generations_cleanup_candidate();
if (!candidate) {
co_return;
}
// We cannot delete the current CDC generation. We must also ensure that timestamps of all deleted
// generations are in the past compared to all nodes' clocks. Checking that the clean-up candidate's
// timestamp does not exceed now() - 24 h should suffice with a safe reserve. We don't have to check
// the timestamps of other CDC generations we are removing because the candidate's is the latest
// among them.
auto ts_upper_bound = db_clock::now() - std::chrono::days(1);
utils::get_local_injector().inject("clean_obsolete_cdc_generations_ignore_ts", [&] {
ts_upper_bound = candidate->ts;
});
if (candidate == _topo_sm._topology.current_cdc_generation_id || candidate->ts > ts_upper_bound) {
co_return;
}
auto mut_ts = guard.write_timestamp();
// Mark the lack of a new clean-up candidate. The current one will be deleted.
mutation m = _sys_ks.make_cleanup_candidate_mutation(std::nullopt, mut_ts);
// Insert a tombstone covering all generations that have time UUID not higher than the candidate.
auto s = _db.find_schema(db::system_keyspace::NAME, db::system_keyspace::CDC_GENERATIONS_V3);
auto id_upper_bound = candidate->id;
auto range = query::clustering_range::make_ending_with({
clustering_key_prefix::from_single_value(*s, timeuuid_type->decompose(id_upper_bound)), true});
auto bv = bound_view::from_range(range);
m.partition().apply_delete(*s, range_tombstone{bv.first, bv.second, tombstone{mut_ts, gc_clock::now()}});
updates.push_back(canonical_mutation(m));
reason += ::format("deleted data of CDC generations with time UUID not exceeding {}", id_upper_bound);
}
// If there are some unpublished CDC generations, publishes the one with the oldest timestamp
// to user-facing description tables. Additionally, if there is no clean-up candidate for the CDC
// generation data, marks the published generation as a new one.
//
// Appends necessary mutations to `updates` and updates the `reason` string.
future<> publish_oldest_cdc_generation(
const group0_guard& guard,
std::vector<canonical_mutation>& updates,
sstring& reason) {
const auto& unpublished_gens = _topo_sm._topology.unpublished_cdc_generations;
if (unpublished_gens.empty()) {
co_return;
}
// The generation under index 0 is the oldest because unpublished_cdc_generations are sorted by timestamp.
auto gen_id = unpublished_gens[0];
auto gen_data = co_await _sys_ks.read_cdc_generation(gen_id.id);
co_await _sys_dist_ks.local().create_cdc_desc(
gen_id.ts, gen_data, { get_token_metadata().count_normal_token_owners() });
std::vector<cdc::generation_id_v2> new_unpublished_gens(unpublished_gens.begin() + 1, unpublished_gens.end());
topology_mutation_builder builder(guard.write_timestamp());
builder.set_unpublished_cdc_generations(std::move(new_unpublished_gens));
updates.push_back(builder.build());
// If there is no clean-up candidate, the published CDC generation becomes a new one.
if (!co_await _sys_ks.get_cdc_generations_cleanup_candidate()) {
auto candidate_mutation = _sys_ks.make_cleanup_candidate_mutation(gen_id, guard.write_timestamp());
updates.push_back(canonical_mutation(candidate_mutation));
}
reason += ::format("published CDC generation with ID {}, ", gen_id);
}
// The background fiber of the topology coordinator that continually publishes committed yet unpublished
// CDC generations. Every generation is published in a separate group 0 operation.
//
// It also continually cleans the obsolete CDC generation data.
future<> cdc_generation_publisher_fiber() {
slogger.trace("raft topology: start CDC generation publisher fiber");
while (!_as.abort_requested()) {
co_await utils::get_local_injector().inject_with_handler("cdc_generation_publisher_fiber", [] (auto& handler) -> future<> {
slogger.info("raft toplogy: CDC generation publisher fiber sleeps after injection");
co_await handler.wait_for_message(std::chrono::steady_clock::now() + std::chrono::minutes{5});
slogger.info("raft toplogy: CDC generation publisher fiber finishes sleeping after injection");
});
bool sleep = false;
try {
auto guard = co_await start_operation();
std::vector<canonical_mutation> updates;
sstring reason;
co_await publish_oldest_cdc_generation(guard, updates, reason);
co_await clean_obsolete_cdc_generations(guard, updates, reason);
if (!updates.empty()) {
co_await update_topology_state(std::move(guard), std::move(updates), std::move(reason));
} else {
release_guard(std::move(guard));
}
if (_topo_sm._topology.unpublished_cdc_generations.empty()) {
// No CDC generations to publish. Wait until one appears or the topology coordinator aborts.
slogger.trace("raft topology: CDC generation publisher fiber has nothing to do. Sleeping.");
co_await _topo_sm.event.when([&] () {
return !_topo_sm._topology.unpublished_cdc_generations.empty() || _as.abort_requested();
});
slogger.trace("raft topology: CDC generation publisher fiber wakes up");
}
} catch (raft::request_aborted&) {
slogger.debug("raft topology: CDC generation publisher fiber aborted");
} catch (seastar::abort_requested_exception) {
slogger.debug("raft topology: CDC generation publisher fiber aborted");
} catch (group0_concurrent_modification&) {
} catch (term_changed_error&) {
slogger.debug("raft topology: CDC generation publisher fiber notices term change {} -> {}", _term, _raft.get_current_term());
} catch (...) {
slogger.error("raft topology: CDC generation publisher fiber got error {}", std::current_exception());
sleep = true;
}
if (sleep) {
try {
co_await seastar::sleep_abortable(std::chrono::seconds(1), _as);
} catch (...) {
slogger.debug("raft topology: CDC generation publisher: sleep failed: {}", std::current_exception());
}
}
co_await coroutine::maybe_yield();
}
}
// Precondition: there is no node request and no ongoing topology transition
// (checked under the guard we're holding).
future<> handle_global_request(group0_guard guard) {
switch (_topo_sm._topology.global_request.value()) {
case global_topology_request::new_cdc_generation: {
slogger.info("raft topology: new CDC generation requested");
auto tmptr = get_token_metadata_ptr();
auto [gen_uuid, guard_, mutation] = co_await prepare_and_broadcast_cdc_generation_data(tmptr, std::move(guard), std::nullopt);
guard = std::move(guard_);
topology_mutation_builder builder(guard.write_timestamp());
// We don't delete the request now, but only after the generation is committed. If we deleted
// the request now and received another new_cdc_generation request later, but before committing
// the new generation, the second request would also create a new generation. Deleting requests
// after the generation is committed prevents this from happening. The second request would have
// no effect - it would just overwrite the first request.
builder.set_transition_state(topology::transition_state::commit_cdc_generation)
.set_new_cdc_generation_data_uuid(gen_uuid);
auto reason = ::format(
"insert CDC generation data (UUID: {})", gen_uuid);
co_await update_topology_state(std::move(guard), {std::move(mutation), builder.build()}, reason);
}
break;
}
}
// Preconditions:
// - There are no topology operations in progress
// - `features_to_enable` represents a set of features that are currently
// marked as supported by all normal nodes and it is not empty
future<> enable_features(group0_guard guard, std::set<sstring> features_to_enable) {
if (!_topo_sm._topology.transition_nodes.empty()) {
on_internal_error(slogger,
"topology coordinator attempted to enable features even though there is"
" a topology operations in progress");
}
if (utils::get_local_injector().enter("raft_topology_suppress_enabling_features")) {
// Prevent enabling features while the injection is enabled.
// The topology coordinator will detect in the next iteration
// that there are still some cluster features to enable and will
// reach this place again. In order not to spin in a loop, sleep
// for a short while.
co_await sleep(std::chrono::milliseconds(100));
co_return;
}
// If we are here, then we noticed that all normal nodes support some
// features that are not enabled yet. Perform a global barrier to make
// sure that:
//
// 1. All normal nodes saw (and persisted) a view of the system.topology
// table that is equal to what the topology coordinator sees (or newer,
// but in that case updating the topology state will fail),
// 2. None of the normal nodes is restarting at the moment and trying to
// downgrade (this is done by a special check in the barrier handler).
//
// It's sufficient to only include normal nodes because:
//
// - There are no transitioning nodes due to the precondition,
// - New and left nodes are not part of group 0.
//
// After we get a successful confirmation from each normal node, we have
// a guarantee that they won't attempt to revoke support for those
// features. That's because we do not allow nodes to boot without
// a feature that is supported by all nodes in the cluster, even if
// the feature is not enabled yet.
guard = co_await exec_global_command(std::move(guard),
raft_topology_cmd{raft_topology_cmd::command::barrier},
{_raft.id()},
drop_guard_and_retake::no);
topology_mutation_builder builder(guard.write_timestamp());
builder.add_enabled_features(features_to_enable);
auto reason = ::format("enabling features: {}", features_to_enable);
co_await update_topology_state(std::move(guard), {builder.build()}, reason);
slogger.info("raft topology: enabled features: {}", features_to_enable);
}
future<group0_guard> global_token_metadata_barrier(group0_guard&& guard, std::unordered_set<raft::server_id> exclude_nodes = {}) {
bool drain_failed = false;
try {
guard = co_await exec_global_command(std::move(guard), raft_topology_cmd::command::barrier_and_drain, exclude_nodes, drop_guard_and_retake::yes);
} catch (...) {
slogger.error("raft topology: drain rpc failed, proceed to fence old writes: {}", std::current_exception());
drain_failed = true;
}
if (drain_failed) {
guard = co_await start_operation();
}
topology_mutation_builder builder(guard.write_timestamp());
builder.set_fence_version(_topo_sm._topology.version);
auto reason = ::format("advance fence version to {}", _topo_sm._topology.version);
co_await update_topology_state(std::move(guard), {builder.build()}, reason);
guard = co_await start_operation();
if (drain_failed) {
// if drain failed need to wait for fence to be active on all nodes
co_return co_await exec_global_command(std::move(guard), raft_topology_cmd::command::barrier, exclude_nodes, drop_guard_and_retake::yes);
} else {
co_return std::move(guard);
}
}
future<group0_guard> global_tablet_token_metadata_barrier(group0_guard guard) {
// FIXME: Don't require all nodes to be up, only tablet replicas.
return global_token_metadata_barrier(std::move(guard));
}
// Represents a two-state state machine which changes monotonically
// from "not executed" to "executed successfully". This state
// machine is transient, lives only on this coordinator.
// The transition is achieved by execution of an idempotent async
// operation which is tracked by a future. Even though the async
// action is idempotent, it is costly, so we want to avoid
// re-executing it if it was already started by this coordinator,
// that's why we track it.
using background_action_holder = std::optional<future<>>;
// Transient state of tablet migration which lives on this coordinator.
// It is guaranteed to die when migration is finished.
// Next migration of the same tablet is guaranteed to use a different instance.
struct tablet_migration_state {
background_action_holder streaming;
background_action_holder cleanup;
std::unordered_map<locator::tablet_transition_stage, background_action_holder> barriers;
};
std::unordered_map<locator::global_tablet_id, tablet_migration_state> _tablets;
// Set to true when any action started on behalf of a background_action_holder
// for any tablet finishes, or fails and needs to be restarted.
bool _tablets_ready = false;
seastar::gate _async_gate;
// This function drives background_action_holder towards "executed successfully"
// by starting the action if it is not already running or if the previous instance
// of the action failed. If the action is already running, it does nothing.
// Returns true iff background_action_holder reached the "executed successfully" state.
bool advance_in_background(locator::global_tablet_id gid, background_action_holder& holder, const char* name,
std::function<future<>()> action) {
if (!holder || holder->failed()) {
holder = futurize_invoke(action)
.finally([this, g = _async_gate.hold(), gid, name] () noexcept {
slogger.trace("raft topology: {} for tablet {} resolved.", name, gid);
_tablets_ready = true;
_topo_sm.event.broadcast();
});
return false;
}
if (!holder->available()) {
slogger.trace("raft topology: Tablet {} still doing {}", gid, name);
return false;
}
return true;
}
future<> for_each_tablet_transition(std::function<void(const locator::tablet_map&,
schema_ptr,
locator::global_tablet_id,
const locator::tablet_transition_info&)> func) {
auto tm = get_token_metadata_ptr();
for (auto&& [table, tmap] : tm->tablets().all_tables()) {
co_await coroutine::maybe_yield();
auto s = _db.find_schema(table);
for (auto&& [tablet, trinfo]: tmap.transitions()) {
co_await coroutine::maybe_yield();
auto gid = locator::global_tablet_id {table, tablet};
func(tmap, s, gid, trinfo);
}
}
}
void generate_migration_update(std::vector<canonical_mutation>& out, const group0_guard& guard, const tablet_migration_info& mig) {
auto s = _db.find_schema(mig.tablet.table);
auto& tmap = get_token_metadata_ptr()->tablets().get_tablet_map(mig.tablet.table);
auto last_token = tmap.get_last_token(mig.tablet.tablet);
if (tmap.get_tablet_transition_info(mig.tablet.tablet)) {
slogger.warn("Tablet already in transition, ignoring migration: {}", mig);
return;
}
out.emplace_back(
replica::tablet_mutation_builder(guard.write_timestamp(), s->ks_name(), mig.tablet.table)
.set_new_replicas(last_token, replace_replica(tmap.get_tablet_info(mig.tablet.tablet).replicas, mig.src, mig.dst))
.set_stage(last_token, locator::tablet_transition_stage::allow_write_both_read_old)
.build());
}
future<> generate_migration_updates(std::vector<canonical_mutation>& out, const group0_guard& guard, const migration_plan& plan) {
for (const tablet_migration_info& mig : plan.migrations()) {
co_await coroutine::maybe_yield();
generate_migration_update(out, guard, mig);
}
}
// When "drain" is true, we migrate tablets only as long as there are nodes to drain
// and then change the transition state to write_both_read_old. Also, while draining,
// we ignore pending topology requests which normally interrupt load balancing.
// When "drain" is false, we do regular load balancing.
future<> handle_tablet_migration(group0_guard guard, bool drain) {
// This step acts like a pump which advances state machines of individual tablets,
// batching barriers and group0 updates.
// If progress cannot be made, e.g. because all transitions are streaming, we block
// and wait for notification.
slogger.trace("raft topology: handle_tablet_migration()");
std::vector<canonical_mutation> updates;
bool needs_barrier = false;
bool has_transitions = false;
shared_promise barrier;
auto fail_barrier = seastar::defer([&] {
if (needs_barrier) {
barrier.set_exception(seastar::broken_promise());
}
});
_tablets_ready = false;
co_await for_each_tablet_transition([&] (const locator::tablet_map& tmap,
schema_ptr s,
locator::global_tablet_id gid,
const locator::tablet_transition_info& trinfo) {
has_transitions = true;
auto last_token = tmap.get_last_token(gid.tablet);
auto& tablet_state = _tablets[gid];
table_id table = s->id();
auto get_mutation_builder = [&] () {
return replica::tablet_mutation_builder(guard.write_timestamp(), s->ks_name(), table);
};
auto transition_to = [&] (locator::tablet_transition_stage stage) {
slogger.trace("raft topology: Will set tablet {} stage to {}", gid, stage);
updates.emplace_back(get_mutation_builder()
.set_stage(last_token, stage)
.build());
};
auto do_barrier = [&] {
return advance_in_background(gid, tablet_state.barriers[trinfo.stage], "barrier", [&] {
needs_barrier = true;
return barrier.get_shared_future();
});
};
auto transition_to_with_barrier = [&] (locator::tablet_transition_stage stage) {
if (do_barrier()) {
transition_to(stage);
}
};
switch (trinfo.stage) {
case locator::tablet_transition_stage::allow_write_both_read_old:
if (do_barrier()) {
slogger.trace("raft topology: Will set tablet {} stage to {}", gid, locator::tablet_transition_stage::write_both_read_old);
updates.emplace_back(get_mutation_builder()
.set_stage(last_token, locator::tablet_transition_stage::write_both_read_old)
// Create session a bit earlier to avoid adding barrier
// to the streaming stage to create sessions on replicas.
.set_session(last_token, session_id(utils::UUID_gen::get_time_UUID()))
.build());
}
break;
case locator::tablet_transition_stage::write_both_read_old:
transition_to_with_barrier(locator::tablet_transition_stage::streaming);
break;
// The state "streaming" is needed to ensure that stale stream_tablet() RPC doesn't
// get admitted before global_tablet_token_metadata_barrier() is finished for earlier
// stage in case of coordinator failover.
case locator::tablet_transition_stage::streaming:
if (drain) {
utils::get_local_injector().inject("stream_tablet_fail_on_drain",
[] { throw std::runtime_error("stream_tablet failed due to error injection"); });
}
if (advance_in_background(gid, tablet_state.streaming, "streaming", [&] {
slogger.info("raft topology: Initiating tablet streaming of {} to {}", gid, trinfo.pending_replica);
auto dst = trinfo.pending_replica.host;
return ser::storage_service_rpc_verbs::send_tablet_stream_data(&_messaging,
netw::msg_addr(id2ip(dst)), _as, raft::server_id(dst.uuid()), gid);
})) {
slogger.trace("raft topology: Will set tablet {} stage to {}", gid, locator::tablet_transition_stage::write_both_read_new);
updates.emplace_back(get_mutation_builder()
.set_stage(last_token, locator::tablet_transition_stage::write_both_read_new)
.del_session(last_token)
.build());
}
break;
case locator::tablet_transition_stage::write_both_read_new:
transition_to_with_barrier(locator::tablet_transition_stage::use_new);
break;
case locator::tablet_transition_stage::use_new:
transition_to_with_barrier(locator::tablet_transition_stage::cleanup);
break;
case locator::tablet_transition_stage::cleanup:
if (advance_in_background(gid, tablet_state.cleanup, "cleanup", [&] {
locator::tablet_replica dst = locator::get_leaving_replica(tmap.get_tablet_info(gid.tablet), trinfo);
slogger.info("raft topology: Initiating tablet cleanup of {} on {}", gid, dst);
return ser::storage_service_rpc_verbs::send_tablet_cleanup(&_messaging,
netw::msg_addr(id2ip(dst.host)), _as, raft::server_id(dst.host.uuid()), gid);
})) {
transition_to(locator::tablet_transition_stage::end_migration);
}
break;
case locator::tablet_transition_stage::end_migration:
// Need a separate stage and a barrier after cleanup RPC to cut off stale RPCs.
// See do_tablet_operation() doc.
if (do_barrier()) {
_tablets.erase(gid);
updates.emplace_back(get_mutation_builder()
.del_transition(last_token)
.set_replicas(last_token, trinfo.next)
.build());
}
break;
}
});
// In order to keep the cluster saturated, ask the load balancer for more transitions.
// Unless there is a pending topology change operation.
bool preempt = false;
if (!drain) {
// When draining, this method is invoked with an active node transition, which
// would normally cause preemption, which we don't want here.
auto ts = guard.write_timestamp();
auto [new_preempt, new_guard] = should_preempt_balancing(std::move(guard));
preempt = new_preempt;
guard = std::move(new_guard);
if (ts != guard.write_timestamp()) {
// We rely on the fact that should_preempt_balancing() does not release the guard
// so that tablet metadata reading and updates are atomic.
on_internal_error(slogger, "should_preempt_balancing() retook the guard");
}
}
if (!preempt) {
auto plan = co_await _tablet_allocator.balance_tablets(get_token_metadata_ptr());
if (!drain || plan.has_nodes_to_drain()) {
co_await generate_migration_updates(updates, guard, plan);
}
}
// The updates have to be executed under the same guard which was used to read tablet metadata
// to ensure that we don't reinsert tablet rows which were concurrently deleted by schema change
// which happens outside the topology coordinator.
bool has_updates = !updates.empty();
if (has_updates) {
updates.emplace_back(
topology_mutation_builder(guard.write_timestamp())
.set_version(_topo_sm._topology.version + 1)
.build());
co_await update_topology_state(std::move(guard), std::move(updates), format("Tablet migration"));
}
if (needs_barrier) {
// If has_updates is true then we have dropped the guard and need to re-obtain it.
// It's fine to start an independent operation here. The barrier doesn't have to be executed
// atomically with the read which set needs_barrier, because it's fine if the global barrier
// works with a more recent set of nodes and it's fine if it propagates a more recent topology.
if (!guard) {
guard = co_await start_operation();
}
guard = co_await global_tablet_token_metadata_barrier(std::move(guard));
barrier.set_value();
fail_barrier.cancel();
}
if (has_updates) {
co_return;
}
if (has_transitions) {
// Streaming may have finished after we checked. To avoid missed notification, we need
// to check atomically with event.wait()
if (!_tablets_ready) {
slogger.trace("raft topology: Going to sleep with active tablet transitions");
release_guard(std::move(guard));
co_await await_event();
}
co_return;
}
if (drain) {
updates.emplace_back(
topology_mutation_builder(guard.write_timestamp())
.set_transition_state(topology::transition_state::write_both_read_old)
.set_session(session_id(guard.new_group0_state_id()))
.set_version(_topo_sm._topology.version + 1)
.build());
} else {
updates.emplace_back(
topology_mutation_builder(guard.write_timestamp())
.del_transition_state()
.set_version(_topo_sm._topology.version + 1)
.build());
}
co_await update_topology_state(std::move(guard), std::move(updates), "Finished tablet migration");
}
// This function must not release and reacquire the guard, callers rely
// on the fact that the block which calls this is atomic.
// FIXME: Don't take the ownership of the guard to make the above guarantee explicit.
std::pair<bool, group0_guard> should_preempt_balancing(group0_guard guard) {
auto node_or_guard = get_node_to_work_on_opt(std::move(guard));
if (auto* node = std::get_if<node_to_work_on>(&node_or_guard)) {
return std::make_pair(true, std::move(node->guard));
}
guard = std::get<group0_guard>(std::move(node_or_guard));
if (_topo_sm._topology.global_request) {
return std::make_pair(true, std::move(guard));
}
if (!_topo_sm._topology.calculate_not_yet_enabled_features().empty()) {
return std::make_pair(true, std::move(guard));
}
return std::make_pair(false, std::move(guard));
}
// Returns `true` iff there was work to do.
future<bool> handle_topology_transition(group0_guard guard) {
auto tstate = _topo_sm._topology.tstate;
if (!tstate) {
// When adding a new source of work, make sure to update should_preempt_balancing() as well.
auto node_or_guard = get_node_to_work_on_opt(std::move(guard));
if (auto* node = std::get_if<node_to_work_on>(&node_or_guard)) {
co_await handle_node_transition(std::move(*node));
co_return true;
}
guard = std::get<group0_guard>(std::move(node_or_guard));
if (_topo_sm._topology.global_request) {
co_await handle_global_request(std::move(guard));
co_return true;
}
if (auto feats = _topo_sm._topology.calculate_not_yet_enabled_features(); !feats.empty()) {
co_await enable_features(std::move(guard), std::move(feats));
co_return true;
}
// If there is no other work, evaluate load and start tablet migration if there is imbalance.
if (co_await maybe_start_tablet_migration(std::move(guard))) {
co_return true;
}
co_return false;
}
switch (*tstate) {
case topology::transition_state::join_group0: {
auto [node, accepted] = co_await finish_accepting_node(get_node_to_work_on(std::move(guard)));
// If responding to the joining node failed, move the node to the left state and
// stop the topology transition.
if (!accepted) {
topology_mutation_builder builder(node.guard.write_timestamp());
builder.del_transition_state()
.with_node(node.id)
.set("node_state", node_state::left);
auto reason = ::format("bootstrap: failed to accept {}", node.id);
co_await update_topology_state(std::move(node.guard), {builder.build()}, reason);
slogger.info("raft topology: node {} moved to left state", node.id);
break;
}
switch (node.rs->state) {
case node_state::bootstrapping: {
assert(!node.rs->ring);
auto num_tokens = std::get<join_param>(node.req_param.value()).num_tokens;
// A node have just been accepted and does not have tokens assigned yet
// Need to assign random tokens to the node
auto tmptr = get_token_metadata_ptr();
auto bootstrap_tokens = dht::boot_strapper::get_random_bootstrap_tokens(
tmptr, num_tokens, dht::check_token_endpoint::yes);
auto [gen_uuid, guard, mutation] = co_await prepare_and_broadcast_cdc_generation_data(
tmptr, take_guard(std::move(node)), bootstrapping_info{bootstrap_tokens, *node.rs});
topology_mutation_builder builder(guard.write_timestamp());
// Write the new CDC generation data through raft.
builder.set_transition_state(topology::transition_state::commit_cdc_generation)
.set_new_cdc_generation_data_uuid(gen_uuid)
.with_node(node.id)
.set("tokens", bootstrap_tokens);
auto reason = ::format(
"bootstrap: insert tokens and CDC generation data (UUID: {})", gen_uuid);
co_await update_topology_state(std::move(guard), {std::move(mutation), builder.build()}, reason);
}
break;
case node_state::replacing: {
assert(!node.rs->ring);
auto replaced_id = std::get<replace_param>(node.req_param.value()).replaced_id;
auto it = _topo_sm._topology.normal_nodes.find(replaced_id);
assert(it != _topo_sm._topology.normal_nodes.end());
assert(it->second.ring && it->second.state == node_state::normal);
topology_mutation_builder builder(node.guard.write_timestamp());
builder.set_transition_state(topology::transition_state::tablet_draining)
.set_version(_topo_sm._topology.version + 1)
.with_node(node.id)
.set("tokens", it->second.ring->tokens);
co_await update_topology_state(take_guard(std::move(node)), {builder.build()},
"replace: transition to tablet_draining and take ownership of the replaced node's tokens");
}
break;
default:
on_internal_error(slogger,
format("raft topology: topology is in join_group0 state, but the node"
" being worked on ({}) is in unexpected state '{}'; should be"
" either 'bootstrapping' or 'replacing'", node.id, node.rs->state));
}
}
break;
case topology::transition_state::commit_cdc_generation: {
// make sure all nodes know about new topology and have the new CDC generation data
// (we require all nodes to be alive for topo change for now)
// Note: if there was a replace or removenode going on, we'd need to put the replaced/removed
// node into `exclude_nodes` parameter in `exec_global_command`, but CDC generations are never
// introduced during replace/remove.
{
auto f = co_await coroutine::as_future(exec_global_command(std::move(guard),
raft_topology_cmd::command::barrier,
{_raft.id()}));
if (f.failed()) {
slogger.error("raft topology: transition_state::commit_cdc_generation, "
"raft_topology_cmd::command::barrier failed, error {}", f.get_exception());
break;
}
guard = std::move(f).get();
}
// We don't need to add delay to the generation timestamp if this is the first generation.
bool add_ts_delay = bool(_topo_sm._topology.current_cdc_generation_id);
// Begin the race.
// See the large FIXME below.
auto cdc_gen_ts = cdc::new_generation_timestamp(add_ts_delay, _ring_delay);
auto cdc_gen_uuid = _topo_sm._topology.new_cdc_generation_data_uuid;
if (!cdc_gen_uuid) {
on_internal_error(slogger,
"raft topology: new CDC generation data UUID missing in `commit_cdc_generation` state");
}
cdc::generation_id_v2 cdc_gen_id {
.ts = cdc_gen_ts,
.id = *cdc_gen_uuid,
};
{
// Sanity check.
// This could happen if the topology coordinator's clock is broken.
auto curr_gen_id = _topo_sm._topology.current_cdc_generation_id;
if (curr_gen_id && curr_gen_id->ts >= cdc_gen_ts) {
on_internal_error(slogger, ::format(
"raft topology: new CDC generation has smaller timestamp than the previous one."
" Old generation ID: {}, new generation ID: {}", *curr_gen_id, cdc_gen_id));
}
}
// Tell all nodes to start using the new CDC generation by updating the topology
// with the generation's ID and timestamp.
// At the same time move the topology change procedure to the next step.
//
// FIXME: as in previous implementation with gossiper and ring_delay, this assumes that all nodes
// will learn about the new CDC generation before their clocks reach the generation's timestamp.
// With this group 0 based implementation, it means that the command must be committed,
// replicated and applied on all nodes before their clocks reach the generation's timestamp
// (i.e. within 2 * ring_delay = 60 seconds by default if clocks are synchronized). If this
// doesn't hold some coordinators might use the wrong CDC streams for some time and CDC stream
// readers will miss some data. It's likely that Raft replication doesn't converge as quickly
// as gossiping does.
//
// We could use a two-phase algorithm instead: first tell all nodes to prepare for using
// the new generation, then tell all nodes to commit. If some nodes don't manage to prepare
// in time, we abort the generation switch. If all nodes prepare, we commit. If a node prepares
// but doesn't receive a commit in time, it stops coordinating CDC-enabled writes until it
// receives a commit or abort. This solution does not have a safety problem like the one
// above, but it has an availability problem when nodes get disconnected from group 0 majority
// in the middle of a CDC generation switch (when they are prepared to switch but not
// committed) - they won't coordinate CDC-enabled writes until they reconnect to the
// majority and commit.
topology_mutation_builder builder(guard.write_timestamp());
builder.set_current_cdc_generation_id(cdc_gen_id)
.add_unpublished_cdc_generation(cdc_gen_id);
if (_topo_sm._topology.global_request == global_topology_request::new_cdc_generation) {
builder.del_global_topology_request();
builder.del_transition_state();
} else {
builder.set_transition_state(topology::transition_state::write_both_read_old);
builder.set_session(session_id(guard.new_group0_state_id()));
builder.set_version(_topo_sm._topology.version + 1);
}
auto str = ::format("committed new CDC generation, ID: {}", cdc_gen_id);
co_await update_topology_state(std::move(guard), {builder.build()}, std::move(str));
}
break;
case topology::transition_state::tablet_draining:
try {
co_await handle_tablet_migration(std::move(guard), true);
} catch (term_changed_error&) {
throw;
} catch (group0_concurrent_modification&) {
throw;
} catch (...) {
slogger.error("raft topology: tablets draining failed with {}. Aborting the topology operation", std::current_exception());
_rollback = true;
}
break;
case topology::transition_state::write_both_read_old: {
auto node = get_node_to_work_on(std::move(guard));
// make sure all nodes know about new topology (we require all nodes to be alive for topo change for now)
try {
node = retake_node(co_await global_token_metadata_barrier(std::move(node.guard), get_excluded_nodes(node)), node.id);
} catch (term_changed_error&) {
throw;
} catch (group0_concurrent_modification&) {
throw;
} catch (...) {
slogger.error("raft topology: transition_state::write_both_read_old, "
"global_token_metadata_barrier failed, error {}",
std::current_exception());
_rollback = true;
break;
}
if (_group0.is_member(node.id, true)) {
// If we remove a node, we make it a non-voter early to improve availability in some situations.
// There is no downside to it because the removed node is already considered dead by us.
//
// FIXME: removenode may be aborted and the already dead node can be resurrected. We should consider
// restoring its voter state on the recovery path.
if (node.rs->state == node_state::removing) {
co_await _group0.make_nonvoter(node.id);
}
// If we decommission a node when the number of nodes is even, we make it a non-voter early.
// All majorities containing this node will remain majorities when we make this node a non-voter
// and remove it from the set because the required size of a majority decreases.
//
// FIXME: when a node restarts and notices it's a non-voter, it will become a voter again. If the
// node restarts during a decommission, and we want the decommission to continue (e.g. because it's
// at a finishing non-abortable step), we must ensure that the node doesn't become a voter.
if (node.rs->state == node_state::decommissioning
&& raft::configuration::voter_count(_group0.group0_server().get_configuration().current) % 2 == 0) {
if (node.id == _raft.id()) {
slogger.info("raft topology: coordinator is decommissioning and becomes a non-voter; "
"giving up leadership");
co_await step_down_as_nonvoter();
} else {
co_await _group0.make_nonvoter(node.id);
}
}
}
if (node.rs->state == node_state::replacing) {
// We make a replaced node a non-voter early, just like a removed node.
auto replaced_node_id = parse_replaced_node(node);
if (_group0.is_member(replaced_node_id, true)) {
co_await _group0.make_nonvoter(replaced_node_id);
}
}
raft_topology_cmd cmd{raft_topology_cmd::command::stream_ranges};
try {
if (node.rs->state == node_state::removing) {
// tell all nodes to stream data of the removed node to new range owners
node = co_await exec_global_command(std::move(node), cmd);
} else {
// Tell joining/leaving/replacing node to stream its ranges
node = co_await exec_direct_command(std::move(node), cmd);
}
} catch (term_changed_error&) {
throw;
} catch (...) {
slogger.error("raft topology: send_raft_topology_cmd(stream_ranges) failed with exception"
" (node state is {}): {}", node.rs->state, std::current_exception());
_rollback = true;
break;
}
// Streaming completed. We can now move tokens state to topology::transition_state::write_both_read_new
topology_mutation_builder builder(node.guard.write_timestamp());
builder
.set_transition_state(topology::transition_state::write_both_read_new)
.del_session()
.set_version(_topo_sm._topology.version + 1);
auto str = ::format("{}: streaming completed for node {}", node.rs->state, node.id);
co_await update_topology_state(take_guard(std::move(node)), {builder.build()}, std::move(str));
}
break;
case topology::transition_state::write_both_read_new: {
auto node = get_node_to_work_on(std::move(guard));
bool barrier_failed = false;
// In this state writes goes to old and new replicas but reads start to be done from new replicas
// Before we stop writing to old replicas we need to wait for all previous reads to complete
try {
node = retake_node(co_await global_token_metadata_barrier(std::move(node.guard), get_excluded_nodes(node)), node.id);
} catch (term_changed_error&) {
throw;
} catch (group0_concurrent_modification&) {
throw;
} catch (...) {
slogger.error("raft topology: transition_state::write_both_read_new, "
"global_token_metadata_barrier failed, error {}",
std::current_exception());
barrier_failed = true;
}
if (barrier_failed) {
// If barrier above failed it means there may be unfenced reads from old replicas.
// Lets wait for the ring delay for those writes to complete or fence to propagate
// before continuing.
// FIXME: nodes that cannot be reached need to be isolated either automatically or
// by an administrator
co_await sleep_abortable(_ring_delay, _as);
}
switch(node.rs->state) {
case node_state::bootstrapping: {
topology_mutation_builder builder(node.guard.write_timestamp());
builder.del_transition_state()
.with_node(node.id)
.set("node_state", node_state::normal);
co_await update_topology_state(take_guard(std::move(node)), {builder.build()},
"bootstrap: read fence completed");
}
break;
case node_state::removing:
co_await remove_from_group0(node.id);
[[fallthrough]];
case node_state::decommissioning: {
topology_mutation_builder builder(node.guard.write_timestamp());
auto next_state = node.rs->state == node_state::decommissioning
? node_state::left_token_ring : node_state::left;
builder.del_transition_state()
.set_version(_topo_sm._topology.version + 1)
.with_node(node.id)
.del("tokens")
.set("node_state", next_state);
auto str = ::format("{}: read fence completed", node.rs->state);
co_await update_topology_state(take_guard(std::move(node)), {builder.build()}, std::move(str));
}
break;
case node_state::replacing: {
auto replaced_node_id = parse_replaced_node(node);
co_await remove_from_group0(replaced_node_id);
topology_mutation_builder builder1(node.guard.write_timestamp());
// Move new node to 'normal'
builder1.del_transition_state()
.set_version(_topo_sm._topology.version + 1)
.with_node(node.id)
.set("node_state", node_state::normal);
// Move old node to 'left'
topology_mutation_builder builder2(node.guard.write_timestamp());
builder2.with_node(replaced_node_id)
.del("tokens")
.set("node_state", node_state::left);
co_await update_topology_state(take_guard(std::move(node)), {builder1.build(), builder2.build()},
"replace: read fence completed");
}
break;
default:
on_fatal_internal_error(slogger, ::format(
"Ring state on node {} is write_both_read_new while the node is in state {}",
node.id, node.rs->state));
}
// Reads are fenced. We can now remove topology::transition_state and move node state to normal
}
break;
case topology::transition_state::tablet_migration:
co_await handle_tablet_migration(std::move(guard), false);
break;
}
co_return true;
};
// Called when there is no ongoing topology transition.
// Used to start new topology transitions using node requests or perform node operations
// that don't change the topology (like rebuild).
future<> handle_node_transition(node_to_work_on&& node) {
slogger.info("raft topology: coordinator fiber found a node to work on id={} state={}", node.id, node.rs->state);
switch (node.rs->state) {
case node_state::none: {
if (_topo_sm._topology.normal_nodes.empty()) {
slogger.info("raft topology: skipping join node handshake for the first node in the cluster");
} else {
auto validation_result = validate_joining_node(node);
if (auto* reject = std::get_if<join_node_response_params::rejected>(&validation_result)) {
// Transition to left
topology_mutation_builder builder(node.guard.write_timestamp());
builder.with_node(node.id)
.del("topology_request")
.set("node_state", node_state::left);
auto reason = ::format("bootstrap: node rejected");
co_await update_topology_state(std::move(node.guard), {builder.build()}, reason);
slogger.info("raft topology: rejected node moved to left state {}", node.id);
try {
co_await respond_to_joining_node(node.id, join_node_response_params{
.response = std::move(validation_result),
});
} catch (const std::runtime_error& e) {
slogger.warn("raft topology: attempt to send rejection response to {} failed: {}. "
"The node may hang. It's safe to shut it down manually now.",
node.id, e.what());
}
break;
}
}
}
[[fallthrough]];
case node_state::normal: {
// if the state is none there have to be either 'join' or 'replace' request
// if the state is normal there have to be either 'leave', 'remove' or 'rebuild' request
topology_mutation_builder builder(node.guard.write_timestamp());
switch (node.request.value()) {
case topology_request::join: {
assert(!node.rs->ring);
// Write chosen tokens through raft.
builder.set_transition_state(topology::transition_state::join_group0)
.with_node(node.id)
.set("node_state", node_state::bootstrapping)
.del("topology_request");
auto reason = ::format("bootstrap: accept node");
co_await update_topology_state(std::move(node.guard), {builder.build()}, reason);
break;
}
case topology_request::leave:
assert(node.rs->ring);
// start decommission and put tokens of decommissioning nodes into write_both_read_old state
// meaning that reads will go to the replica being decommissioned
// but writes will go to new owner as well
builder.set_transition_state(topology::transition_state::tablet_draining)
.set_version(_topo_sm._topology.version + 1)
.with_node(node.id)
.set("node_state", node_state::decommissioning)
.del("topology_request");
co_await update_topology_state(take_guard(std::move(node)), {builder.build()},
"start decommission");
break;
case topology_request::remove:
assert(node.rs->ring);
builder.set_transition_state(topology::transition_state::tablet_draining)
.set_version(_topo_sm._topology.version + 1)
.with_node(node.id)
.set("node_state", node_state::removing)
.del("topology_request");
co_await update_topology_state(take_guard(std::move(node)), {builder.build()},
"start removenode");
break;
case topology_request::replace: {
assert(!node.rs->ring);
builder.set_transition_state(topology::transition_state::join_group0)
.with_node(node.id)
.set("node_state", node_state::replacing)
.del("topology_request");
co_await update_topology_state(take_guard(std::move(node)), {builder.build()},
"replace: accept node");
break;
}
case topology_request::rebuild: {
topology_mutation_builder builder(node.guard.write_timestamp());
builder.with_node(node.id)
.set("node_state", node_state::rebuilding)
.del("topology_request");
co_await update_topology_state(take_guard(std::move(node)), {builder.build()},
"start rebuilding");
break;
}
}
break;
}
case node_state::rebuilding: {
node = co_await exec_direct_command(
std::move(node), raft_topology_cmd::command::stream_ranges);
topology_mutation_builder builder(node.guard.write_timestamp());
builder.with_node(node.id)
.set("node_state", node_state::normal)
.del("rebuild_option");
co_await update_topology_state(take_guard(std::move(node)), {builder.build()}, "rebuilding completed");
}
break;
case node_state::left_token_ring: {
if (node.id == _raft.id()) {
// Someone else needs to coordinate the rest of the decommission process,
// because the decommissioning node is going to shut down in the middle of this state.
slogger.info("raft topology: coordinator is decommissioning; giving up leadership");
co_await step_down_as_nonvoter();
// Note: if we restart after this point and become a voter
// and then a coordinator again, it's fine - we'll just repeat this step.
// (If we're in `left` state when we try to restart we won't
// be able to become a voter - we'll be banned from the cluster.)
}
bool barrier_failed = false;
// Wait until other nodes observe the new token ring and stop sending writes to this node.
try {
node = retake_node(co_await global_token_metadata_barrier(std::move(node.guard), get_excluded_nodes(node)), node.id);
} catch (term_changed_error&) {
throw;
} catch (group0_concurrent_modification&) {
throw;
} catch (...) {
slogger.error("raft topology: node_state::left_token_ring (node: {}), "
"global_token_metadata_barrier failed, error {}",
node.id, std::current_exception());
barrier_failed = true;
}
if (barrier_failed) {
// If barrier above failed it means there may be unfinished writes to a decommissioned node.
// Lets wait for the ring delay for those writes to complete and new topology to propagate
// before continuing.
co_await sleep_abortable(_ring_delay, _as);
}
// Tell the node to shut down.
// This is done to improve user experience when there are no failures.
// In the next state (`node_state::left`), the node will be banned by the rest of the cluster,
// so there's no guarantee that it would learn about entering that state even if it was still
// a member of group0, hence we use a separate direct RPC in this state to shut it down.
//
// There is the possibility that the node will never get the message
// and decommission will hang on that node.
// This is fine for the rest of the cluster - we will still remove, ban the node and continue.
auto node_id = node.id;
bool shutdown_failed = false;
try {
node = co_await exec_direct_command(std::move(node), raft_topology_cmd::command::shutdown);
} catch (...) {
slogger.warn("raft topology: failed to tell node {} to shut down - it may hang."
" It's safe to shut it down manually now. (Exception: {})",
node.id, std::current_exception());
shutdown_failed = true;
}
if (shutdown_failed) {
node = retake_node(co_await start_operation(), node_id);
}
// Remove the node from group0 here - in general, it won't be able to leave on its own
// because we'll ban it as soon as we tell it to shut down.
co_await remove_from_group0(node.id);
topology_mutation_builder builder(node.guard.write_timestamp());
builder.with_node(node.id)
.set("node_state", node_state::left);
auto str = ::format("finished decommissioning node {}", node.id);
co_await update_topology_state(take_guard(std::move(node)), {builder.build()}, std::move(str));
}
break;
case node_state::rollback_to_normal: {
// The barrier waits for all double writes started during the operation to complete. It allowed to fail
// since we will fence the requests later.
bool barrier_failed = false;
try {
node.guard = co_await exec_global_command(std::move(node.guard),raft_topology_cmd::command::barrier_and_drain, get_excluded_nodes(node), drop_guard_and_retake::yes);
} catch (term_changed_error&) {
throw;
} catch(...) {
slogger.warn("raft topology: failed to run barrier_and_drain during rollback {}", std::current_exception());
barrier_failed = true;
}
if (barrier_failed) {
node.guard =co_await start_operation();
}
node = retake_node(std::move(node.guard), node.id);
topology_mutation_builder builder(node.guard.write_timestamp());
builder.set_fence_version(_topo_sm._topology.version) // fence requests in case the drain above failed
.set_transition_state(topology::transition_state::tablet_migration) // in case tablet drain failed we need to complete tablet transitions
.with_node(node.id)
.set("node_state", node_state::normal);
auto str = fmt::format("complete rollback of {} to state normal", node.id);
slogger.info("{}", str);
co_await update_topology_state(std::move(node.guard), {builder.build()}, str);
}
break;
case node_state::bootstrapping:
case node_state::decommissioning:
case node_state::removing:
case node_state::replacing:
// Should not get here
on_fatal_internal_error(slogger, ::format(
"Found node {} in state {} but there is no ongoing topology transition",
node.id, node.rs->state));
case node_state::left:
// Should not get here
on_fatal_internal_error(slogger, ::format(
"Topology coordinator is called for node {} in state 'left'", node.id));
break;
}
};
std::variant<join_node_response_params::accepted, join_node_response_params::rejected>
validate_joining_node(const node_to_work_on& node) {
if (*node.request == topology_request::replace) {
auto replaced_id = std::get<replace_param>(node.req_param.value()).replaced_id;
if (!_topo_sm._topology.normal_nodes.contains(replaced_id)) {
return join_node_response_params::rejected {
.reason = ::format("Cannot replace node {} because it is not in the 'normal' state", replaced_id),
};
}
auto replaced_ip = id2ip(locator::host_id(replaced_id.uuid()));
if (_gossiper.is_alive(replaced_ip)) {
return join_node_response_params::rejected {
.reason = ::format("Cannot replace node {} because it is considered alive", replaced_id),
};
}
}
std::vector<sstring> unsupported_features;
const auto& supported_features = node.rs->supported_features;
std::ranges::set_difference(node.topology->enabled_features, supported_features, std::back_inserter(unsupported_features));
if (!unsupported_features.empty()) {
slogger.warn("raft topology: node {} does not understand some features: {}", node.id, unsupported_features);
return join_node_response_params::rejected{
.reason = format("Feature check failed. The node does not support some features that are enabled by the cluster: {}",
unsupported_features),
};
}
return join_node_response_params::accepted {};
}
// Tries to finish accepting the joining node by updating the cluster
// configuration and sending the acceptance response.
//
// Returns the retaken node and information on whether responding to the
// join request succeeded.
future<std::tuple<node_to_work_on, bool>> finish_accepting_node(node_to_work_on&& node) {
if (_topo_sm._topology.normal_nodes.empty()) {
// This is the first node, it joins without the handshake.
co_return std::tuple{std::move(node), true};
}
auto id = node.id;
assert(!_topo_sm._topology.transition_nodes.empty());
if (!_raft.get_configuration().contains(id)) {
co_await _raft.modify_config({raft::config_member({id, {}}, {})}, {});
}
release_node(std::move(node));
auto responded = false;
try {
co_await respond_to_joining_node(id, join_node_response_params{
.response = join_node_response_params::accepted{},
});
responded = true;
} catch (const std::runtime_error& e) {
slogger.warn("raft topology: attempt to send acceptance response to {} failed: {}. "
"The node may hang. It's safe to shut it down manually now.",
node.id, e.what());
}
co_return std::tuple{retake_node(co_await start_operation(), id), responded};
}
future<> respond_to_joining_node(raft::server_id id, join_node_response_params&& params) {
auto ip = id2ip(locator::host_id(id.uuid()));
co_await ser::join_node_rpc_verbs::send_join_node_response(
&_messaging, netw::msg_addr(ip), id,
std::move(params)
);
}
// Returns true if the state machine was transitioned into tablet migration path.
future<bool> maybe_start_tablet_migration(group0_guard);
future<> await_event() {
_as.check();
co_await _topo_sm.event.when();
}
future<> fence_previous_coordinator();
future<> rollback_current_topology_op(group0_guard&& guard);
public:
topology_coordinator(
sharded<db::system_distributed_keyspace>& sys_dist_ks, gms::gossiper& gossiper,
netw::messaging_service& messaging, locator::shared_token_metadata& shared_tm,
db::system_keyspace& sys_ks, replica::database& db, service::raft_group0& group0,
service::topology_state_machine& topo_sm, abort_source& as, raft::server& raft_server,
raft_topology_cmd_handler_type raft_topology_cmd_handler,
tablet_allocator& tablet_allocator,
std::chrono::milliseconds ring_delay)
: _sys_dist_ks(sys_dist_ks), _gossiper(gossiper), _messaging(messaging)
, _shared_tm(shared_tm), _sys_ks(sys_ks), _db(db)
, _group0(group0), _address_map(_group0.address_map()), _topo_sm(topo_sm), _as(as)
, _raft(raft_server), _term(raft_server.get_current_term())
, _raft_topology_cmd_handler(std::move(raft_topology_cmd_handler))
, _tablet_allocator(tablet_allocator)
, _ring_delay(ring_delay)
{}
future<> run();
};
future<bool> topology_coordinator::maybe_start_tablet_migration(group0_guard guard) {
slogger.debug("raft topology: Evaluating tablet balance");
auto tm = get_token_metadata_ptr();
auto plan = co_await _tablet_allocator.balance_tablets(tm);
if (plan.empty()) {
slogger.debug("raft topology: Tablets are balanced");
co_return false;
}
std::vector<canonical_mutation> updates;
co_await generate_migration_updates(updates, guard, plan);
updates.emplace_back(
topology_mutation_builder(guard.write_timestamp())
.set_transition_state(topology::transition_state::tablet_migration)
.set_version(_topo_sm._topology.version + 1)
.build());
co_await update_topology_state(std::move(guard), std::move(updates), "Starting tablet migration");
co_return true;
}
future<> topology_coordinator::fence_previous_coordinator() {
// Write empty change to make sure that a guard taken by any previous coordinator cannot
// be used to do a successful write any more. Otherwise the following can theoretically happen
// while a coordinator tries to execute RPC R and move to state S.
// 1. Leader A executes topology RPC R
// 2. Leader A takes guard G
// 3. Leader A calls update_topology_state(S)
// 4. Leadership moves to B (while update_topology_state is still running)
// 5. B executed topology RPC R again
// 6. while the RPC is running leadership moves to A again
// 7. A completes update_topology_state(S)
// Topology state machine moves to state S while RPC R is still running.
// If RPC is idempotent that should not be a problem since second one executed by B will do nothing,
// but better to be safe and cut off previous write attempt
while (!_as.abort_requested()) {
try {
auto guard = co_await start_operation();
topology_mutation_builder builder(guard.write_timestamp());
co_await update_topology_state(std::move(guard), {builder.build()}, fmt::format("Starting new topology coordinator {}", _group0.group0_server().id()));
break;
} catch (group0_concurrent_modification&) {
// If we failed to write because of concurrent modification lets retry
continue;
} catch (raft::request_aborted&) {
// Abort was requested. Break the loop
slogger.debug("raft topology: request to fence previous coordinator was aborted");
break;
} catch (...) {
slogger.error("raft topology: failed to fence previous coordinator {}", std::current_exception());
}
try {
co_await seastar::sleep_abortable(std::chrono::seconds(1), _as);
} catch (abort_requested_exception&) {
// Abort was requested. Break the loop
break;
} catch (...) {
slogger.debug("raft topology: sleep failed while fencing previous coordinator: {}", std::current_exception());
}
}
}
future<> topology_coordinator::rollback_current_topology_op(group0_guard&& guard) {
slogger.info("raft topology: start rolling back topology change");
// Look for a node which operation should be aborted
// (there should be one since we are in the rollback)
node_to_work_on node = get_node_to_work_on(std::move(guard));
node_state state;
std::unordered_set<raft::server_id> exclude_nodes = parse_ignore_nodes(node);
switch (node.rs->state) {
case node_state::bootstrapping:
[[fallthrough]];
case node_state::replacing:
// To rollback bootstrap of replace just move a node that we tried to add to the left_token_ring state.
// It will be removed from the group0 by the state handler. It will also be notified to shutdown.
state = node_state::left_token_ring;
break;
case node_state::removing:
// Exclude dead node from global barrier
exclude_nodes.emplace(node.id);
// The node was removed already. We need to add it back. Lets do it as non voter.
// If it ever boots again it will make itself a voter.
co_await _group0.group0_server().modify_config({raft::config_member{{node.id, {}}, false}}, {}, &_as);
[[fallthrough]];
case node_state::decommissioning:
// to rollback decommission or remove just move a node that we tried to remove back to normal state
state = node_state::rollback_to_normal;
break;
default:
on_internal_error(slogger, fmt::format("raft topology: tried to rollback in unsupported state {}", node.rs->state));
}
topology_mutation_builder builder(node.guard.write_timestamp());
builder.del_transition_state()
.set_version(_topo_sm._topology.version + 1)
.with_node(node.id)
.set("node_state", state);
auto str = fmt::format("rollback {} after {} failure to state {}", node.id, node.rs->state, state);
slogger.info("{}", str);
co_await update_topology_state(std::move(node.guard), {builder.build()}, str);
}
future<> topology_coordinator::run() {
slogger.info("raft topology: start topology coordinator fiber");
auto abort = _as.subscribe([this] () noexcept {
_topo_sm.event.broadcast();
});
co_await fence_previous_coordinator();
auto cdc_generation_publisher = cdc_generation_publisher_fiber();
while (!_as.abort_requested()) {
bool sleep = false;
try {
auto guard = co_await start_operation();
co_await cleanup_group0_config_if_needed();
if (_rollback) {
co_await rollback_current_topology_op(std::move(guard));
_rollback = false;
continue;
}
bool had_work = co_await handle_topology_transition(std::move(guard));
if (!had_work) {
// Nothing to work on. Wait for topology change event.
slogger.trace("raft topology: topology coordinator fiber has nothing to do. Sleeping.");
co_await await_event();
slogger.trace("raft topology: topology coordinator fiber got an event");
}
} catch (raft::request_aborted&) {
slogger.debug("raft topology: topology change coordinator fiber aborted");
} catch (seastar::abort_requested_exception&) {
slogger.debug("raft topology: topology change coordinator fiber aborted");
} catch (raft::commit_status_unknown&) {
slogger.warn("raft topology: topology change coordinator fiber got commit_status_unknown");
} catch (group0_concurrent_modification&) {
} catch (term_changed_error&) {
// Term changed. We may no longer be a leader
slogger.debug("raft topology: topology change coordinator fiber notices term change {} -> {}", _term, _raft.get_current_term());
} catch (...) {
slogger.error("raft topology: topology change coordinator fiber got error {}", std::current_exception());
sleep = true;
}
if (sleep) {
try {
co_await seastar::sleep_abortable(std::chrono::seconds(1), _as);
} catch (...) {
slogger.debug("raft topology: sleep failed: {}", std::current_exception());
}
}
co_await coroutine::maybe_yield();
}
co_await _async_gate.close();
co_await std::move(cdc_generation_publisher);
}
future<> storage_service::raft_state_monitor_fiber(raft::server& raft, sharded<db::system_distributed_keyspace>& sys_dist_ks) {
std::optional<abort_source> as;
try {
while (!_group0_as.abort_requested()) {
// Wait for a state change in case we are not a leader yet, or we are are the leader
// and coordinator work is running (in which case 'as' is engaged)
while (!raft.is_leader() || as) {
co_await raft.wait_for_state_change(&_group0_as);
if (as) {
as->request_abort(); // we are no longer a leader, so abort the coordinator
co_await std::exchange(_topology_change_coordinator, make_ready_future<>());
as = std::nullopt;
try {
_tablet_allocator.local().on_leadership_lost();
} catch (...) {
slogger.error("tablet_allocator::on_leadership_lost() failed: {}", std::current_exception());
}
}
}
// We are the leader now but that can change any time!
as.emplace();
// start topology change coordinator in the background
_topology_change_coordinator = do_with(
std::make_unique<topology_coordinator>(
sys_dist_ks, _gossiper, _messaging.local(), _shared_token_metadata,
_sys_ks.local(), _db.local(), *_group0, _topology_state_machine, *as, raft,
std::bind_front(&storage_service::raft_topology_cmd_handler, this),
_tablet_allocator.local(),
get_ring_delay()),
std::ref(raft),
[] (std::unique_ptr<topology_coordinator>& coordinator, raft::server& raft) -> future<> {
std::exception_ptr ex;
try {
co_await coordinator->run();
} catch (...) {
ex = std::current_exception();
}
if (ex) {
try {
if (raft.is_leader()) {
slogger.warn("raft topology: unhandled exception in topology_coordinator::run: {}; stepping down as a leader", ex);
const auto stepdown_timeout_ticks = std::chrono::seconds(5) / raft_tick_interval;
co_await raft.stepdown(raft::logical_clock::duration(stepdown_timeout_ticks));
}
} catch (...) {
slogger.error("raft topology: failed to step down before aborting: {}", std::current_exception());
}
on_fatal_internal_error(slogger, format("raft topology: unhandled exception in topology_coordinator::run: {}", ex));
}
});
}
} catch (...) {
slogger.info("raft_state_monitor_fiber aborted with {}", std::current_exception());
}
if (as) {
as->request_abort(); // abort current coordinator if running
co_await std::move(_topology_change_coordinator);
}
}
std::unordered_set<raft::server_id> storage_service::find_raft_nodes_from_hoeps(const std::list<locator::host_id_or_endpoint>& hoeps) {
std::unordered_set<raft::server_id> ids;
for (const auto& hoep : hoeps) {
std::optional<raft::server_id> id;
if (hoep.has_host_id()) {
id = raft::server_id{hoep.id.uuid()};
} else {
id = _group0->address_map().find_by_addr(hoep.endpoint);
if (!id) {
throw std::runtime_error(::format("Cannot find a mapping to IP {}", hoep.endpoint));
}
}
if (!_topology_state_machine._topology.find(*id)) {
throw std::runtime_error(::format("Node {} is not found in the cluster", id));
}
ids.insert(*id);
}
return ids;
}
canonical_mutation storage_service::build_mutation_from_join_params(const join_node_request_params& params, service::group0_guard& guard) {
topology_mutation_builder builder(guard.write_timestamp());
auto& node_builder = builder.with_node(params.host_id)
.set("node_state", node_state::none)
.set("datacenter", params.datacenter)
.set("rack", params.rack)
.set("release_version", params.release_version)
.set("num_tokens", params.num_tokens)
.set("shard_count", params.shard_count)
.set("ignore_msb", params.ignore_msb)
.set("supported_features", boost::copy_range<std::set<sstring>>(params.supported_features));
if (params.replaced_id) {
std::list<locator::host_id_or_endpoint> ignore_nodes_params;
for (const auto& n : params.ignore_nodes) {
ignore_nodes_params.emplace_back(n);
}
auto ignored_ids = find_raft_nodes_from_hoeps(ignore_nodes_params);
node_builder
.set("topology_request", topology_request::replace)
.set("replaced_id", *params.replaced_id)
.set("ignore_nodes", ignored_ids);
} else {
node_builder
.set("topology_request", topology_request::join);
}
return builder.build();
}
class join_node_rpc_handshaker : public service::group0_handshaker {
private:
service::storage_service& _ss;
const join_node_request_params& _req;
public:
join_node_rpc_handshaker(service::storage_service& ss, const join_node_request_params& req)
: _ss(ss)
, _req(req)
{}
future<> pre_server_start(const group0_info& g0_info) override {
slogger.info("raft topology: join: sending the join request to {}", g0_info.ip_addr);
auto result = co_await ser::join_node_rpc_verbs::send_join_node_request(
&_ss._messaging.local(), netw::msg_addr(g0_info.ip_addr), g0_info.id, _req);
std::visit(overloaded_functor {
[this] (const join_node_request_result::ok&) {
slogger.info("raft topology: join: request to join placed, waiting"
" for the response from the topology coordinator");
_ss._join_node_request_done.set_value();
},
[] (const join_node_request_result::rejected& rej) {
throw std::runtime_error(
format("the topology coordinator rejected request to join the cluster: {}", rej.reason));
},
}, result.result);
co_return;
}
future<bool> post_server_start(const group0_info& g0_info, abort_source& as) override {
// Group 0 has been started. Allow the join_node_response to be handled.
_ss._join_node_group0_started.set_value();
// Processing of the response is done in `join_node_response_handler`.
// Wait for it to complete. If the topology coordinator fails to
// deliver the rejection, it won't complete. In such a case, the
// operator is responsible for shutting down the joining node.
co_await _ss._join_node_response_done.get_shared_future(as);
slogger.info("raft topology: join: success");
co_return true;
}
};
future<> storage_service::raft_initialize_discovery_leader(raft::server& raft_server, const join_node_request_params& params) {
if (_topology_state_machine._topology.is_empty()) {
co_await raft_server.read_barrier(&_group0_as);
}
while (_topology_state_machine._topology.is_empty()) {
if (params.replaced_id.has_value()) {
throw std::runtime_error(::format("Cannot perform a replace operation because this is the first node in the cluster"));
}
slogger.info("raft topology: adding myself as the first node to the topology");
auto guard = co_await _group0->client().start_operation(&_group0_as);
auto insert_join_request_mutation = build_mutation_from_join_params(params, guard);
// We are the first node and we define the cluster.
// Set the enabled_features field to our features.
topology_mutation_builder builder(guard.write_timestamp());
builder.add_enabled_features(boost::copy_range<std::set<sstring>>(params.supported_features));
auto enable_features_mutation = builder.build();
topology_change change{{std::move(enable_features_mutation), std::move(insert_join_request_mutation)}};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard,
"bootstrap: adding myself as the first node to the topology");
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard), &_group0_as);
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: bootstrap: concurrent operation is detected, retrying.");
}
}
}
future<> storage_service::update_topology_with_local_metadata(raft::server& raft_server) {
// TODO: include more metadata here
auto local_shard_count = smp::count;
auto local_ignore_msb = _db.local().get_config().murmur3_partitioner_ignore_msb_bits();
auto local_release_version = version::release();
auto local_supported_features = boost::copy_range<std::set<sstring>>(_feature_service.supported_feature_set());
auto synchronized = [&] () {
auto it = _topology_state_machine._topology.find(raft_server.id());
if (!it) {
throw std::runtime_error{"Removed from topology while performing metadata update"};
}
auto& replica_state = it->second;
return replica_state.shard_count == local_shard_count
&& replica_state.ignore_msb == local_ignore_msb
&& replica_state.release_version == local_release_version
&& replica_state.supported_features == local_supported_features;
};
// We avoid performing a read barrier if we're sure that our metadata stored in topology
// is the same as local metadata. Note that only we can update our metadata, other nodes cannot.
//
// We use a persisted flag `must_update_topology` to avoid the following scenario:
// 1. the node restarts and its metadata changes
// 2. the node commits the new metadata to topology, but before the update is applied
// to the local state machine, the node crashes
// 3. then the metadata changes back to old values and node restarts again
// 4. the local state machine tells us that we're in sync, which is wrong
// If the persisted flag is true, it tells us that we attempted a metadata change earlier,
// forcing us to perform a read barrier even when the local state machine tells us we're in sync.
if (synchronized() && !(co_await _sys_ks.local().get_must_synchronize_topology())) {
co_return;
}
while (true) {
slogger.info("raft topology: refreshing topology to check if it's synchronized with local metadata");
auto guard = co_await _group0->client().start_operation(&_group0_as);
if (synchronized()) {
break;
}
// It might happen that, in the previous run, the node commits a command
// that adds support for a feature, crashes before applying it and now
// it is not safe to disable support for it. If there is an attempt to
// downgrade the node then `enable_features_on_startup` called much
// earlier won't catch it, we only can do it here after performing
// a read barrier - so we repeat it here.
//
// Fortunately, there is no risk that this feature was marked as enabled
// because it requires that the current node responded to a barrier
// request - which will fail in this situation.
const auto& enabled_features = _topology_state_machine._topology.enabled_features;
const auto unsafe_to_disable_features = _topology_state_machine._topology.calculate_not_yet_enabled_features();
_feature_service.check_features(enabled_features, unsafe_to_disable_features);
slogger.info("raft topology: updating topology with local metadata");
co_await _sys_ks.local().set_must_synchronize_topology(true);
topology_mutation_builder builder(guard.write_timestamp());
builder.with_node(raft_server.id())
.set("shard_count", local_shard_count)
.set("ignore_msb", local_ignore_msb)
.set("release_version", local_release_version)
.set("supported_features", local_supported_features);
topology_change change{{builder.build()}};
group0_command g0_cmd = _group0->client().prepare_command(
std::move(change), guard, ::format("{}: update topology with local metadata", raft_server.id()));
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard), &_group0_as);
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: update topology with local metadata:"
" concurrent operation is detected, retrying.");
}
}
co_await _sys_ks.local().set_must_synchronize_topology(false);
}
future<> storage_service::join_token_ring(sharded<db::system_distributed_keyspace>& sys_dist_ks,
sharded<service::storage_proxy>& proxy,
std::unordered_set<gms::inet_address> initial_contact_nodes,
std::unordered_set<gms::inet_address> loaded_endpoints,
std::unordered_map<gms::inet_address, sstring> loaded_peer_features,
std::chrono::milliseconds delay) {
std::unordered_set<token> bootstrap_tokens;
std::map<gms::application_state, gms::versioned_value> app_states;
/* The timestamp of the CDC streams generation that this node has proposed when joining.
* This value is nullopt only when:
* 1. this node is being upgraded from a non-CDC version,
* 2. this node is starting for the first time or restarting with CDC previously disabled,
* in which case the value should become populated before we leave the join_token_ring procedure.
*
* Important: this variable is using only during the startup procedure. It is moved out from
* at the end of `join_token_ring`; the responsibility handling of CDC generations is passed
* to cdc::generation_service.
*
* DO NOT use this variable after `join_token_ring` (i.e. after we call `generation_service::after_join`
* and pass it the ownership of the timestamp.
*/
std::optional<cdc::generation_id> cdc_gen_id;
if (_sys_ks.local().was_decommissioned()) {
if (_db.local().get_config().override_decommission() && !_db.local().get_config().consistent_cluster_management()) {
slogger.warn("This node was decommissioned, but overriding by operator request.");
co_await _sys_ks.local().set_bootstrap_state(db::system_keyspace::bootstrap_state::COMPLETED);
} else {
auto msg = sstring("This node was decommissioned and will not rejoin the ring unless override_decommission=true has been set and consistent cluster management is not in use,"
"or all existing data is removed and the node is bootstrapped again");
slogger.error("{}", msg);
throw std::runtime_error(msg);
}
}
bool replacing_a_node_with_same_ip = false;
bool replacing_a_node_with_diff_ip = false;
std::optional<replacement_info> ri;
std::optional<gms::inet_address> replace_address;
std::optional<locator::host_id> replaced_host_id;
std::optional<raft_group0::replace_info> raft_replace_info;
auto tmlock = std::make_unique<token_metadata_lock>(co_await get_token_metadata_lock());
auto tmptr = co_await get_mutable_token_metadata_ptr();
if (is_replacing()) {
if (_sys_ks.local().bootstrap_complete()) {
throw std::runtime_error("Cannot replace address with a node that is already bootstrapped");
}
ri = co_await prepare_replacement_info(initial_contact_nodes, loaded_peer_features);
replace_address = ri->address;
raft_replace_info = raft_group0::replace_info {
.ip_addr = *replace_address,
.raft_id = raft::server_id{ri->host_id.uuid()},
};
replacing_a_node_with_same_ip = *replace_address == get_broadcast_address();
replacing_a_node_with_diff_ip = *replace_address != get_broadcast_address();
if (!_raft_topology_change_enabled) {
bootstrap_tokens = std::move(ri->tokens);
slogger.info("Replacing a node with {} IP address, my address={}, node being replaced={}",
get_broadcast_address() == *replace_address ? "the same" : "a different",
get_broadcast_address(), *replace_address);
tmptr->update_topology(*replace_address, std::move(ri->dc_rack), locator::node::state::being_replaced);
co_await tmptr->update_normal_tokens(bootstrap_tokens, *replace_address);
replaced_host_id = ri->host_id;
}
} else if (should_bootstrap()) {
co_await check_for_endpoint_collision(initial_contact_nodes, loaded_peer_features);
} else {
auto local_features = _feature_service.supported_feature_set();
slogger.info("Performing gossip shadow round, initial_contact_nodes={}", initial_contact_nodes);
co_await _gossiper.do_shadow_round(initial_contact_nodes, gms::gossiper::mandatory::no);
if (!_raft_topology_change_enabled) {
_gossiper.check_knows_remote_features(local_features, loaded_peer_features);
}
_gossiper.check_snitch_name_matches(_snitch.local()->get_name());
// Check if the node is already removed from the cluster
auto local_host_id = get_token_metadata().get_my_id();
auto my_ip = get_broadcast_address();
if (!_gossiper.is_safe_for_restart(my_ip, local_host_id)) {
throw std::runtime_error(::format("The node {} with host_id {} is removed from the cluster. Can not restart the removed node to join the cluster again!",
my_ip, local_host_id));
}
co_await _gossiper.reset_endpoint_state_map();
for (auto ep : loaded_endpoints) {
co_await _gossiper.add_saved_endpoint(ep);
}
}
auto features = _feature_service.supported_feature_set();
slogger.info("Save advertised features list in the 'system.{}' table", db::system_keyspace::LOCAL);
// Save the advertised feature set to system.local table after
// all remote feature checks are complete and after gossip shadow rounds are done.
// At this point, the final feature set is already determined before the node joins the ring.
co_await _sys_ks.local().save_local_supported_features(features);
// If this is a restarting node, we should update tokens before gossip starts
auto my_tokens = co_await _sys_ks.local().get_saved_tokens();
bool restarting_normal_node = _sys_ks.local().bootstrap_complete() && !is_replacing() && !my_tokens.empty();
if (restarting_normal_node) {
slogger.info("Restarting a node in NORMAL status");
// This node must know about its chosen tokens before other nodes do
// since they may start sending writes to this node after it gossips status = NORMAL.
// Therefore we update _token_metadata now, before gossip starts.
tmptr->update_topology(get_broadcast_address(), _snitch.local()->get_location(), locator::node::state::normal);
co_await tmptr->update_normal_tokens(my_tokens, get_broadcast_address());
cdc_gen_id = co_await _sys_ks.local().get_cdc_generation_id();
if (!cdc_gen_id) {
// We could not have completed joining if we didn't generate and persist a CDC streams timestamp,
// unless we are restarting after upgrading from non-CDC supported version.
// In that case we won't begin a CDC generation: it should be done by one of the nodes
// after it learns that it everyone supports the CDC feature.
cdc_log.warn(
"Restarting node in NORMAL status with CDC enabled, but no streams timestamp was proposed"
" by this node according to its local tables. Are we upgrading from a non-CDC supported version?");
}
}
// have to start the gossip service before we can see any info on other nodes. this is necessary
// for bootstrap to get the load info it needs.
// (we won't be part of the storage ring though until we add a counterId to our state, below.)
// Seed the host ID-to-endpoint map with our own ID.
auto local_host_id = get_token_metadata().get_my_id();
if (!replacing_a_node_with_diff_ip) {
auto endpoint = get_broadcast_address();
auto eps = _gossiper.get_endpoint_state_ptr(endpoint);
if (eps) {
auto replace_host_id = _gossiper.get_host_id(get_broadcast_address());
slogger.info("Host {}/{} is replacing {}/{} using the same address", local_host_id, endpoint, replace_host_id, endpoint);
}
tmptr->update_host_id(local_host_id, get_broadcast_address());
}
// Replicate the tokens early because once gossip runs other nodes
// might send reads/writes to this node. Replicate it early to make
// sure the tokens are valid on all the shards.
co_await replicate_to_all_cores(std::move(tmptr));
tmlock.reset();
auto broadcast_rpc_address = get_token_metadata_ptr()->get_topology().my_cql_address();
// Ensure we know our own actual Schema UUID in preparation for updates
co_await db::schema_tables::recalculate_schema_version(_sys_ks, proxy, _feature_service);
app_states.emplace(gms::application_state::NET_VERSION, versioned_value::network_version());
app_states.emplace(gms::application_state::HOST_ID, versioned_value::host_id(local_host_id));
app_states.emplace(gms::application_state::RPC_ADDRESS, versioned_value::rpcaddress(broadcast_rpc_address));
app_states.emplace(gms::application_state::RELEASE_VERSION, versioned_value::release_version());
app_states.emplace(gms::application_state::SUPPORTED_FEATURES, versioned_value::supported_features(features));
app_states.emplace(gms::application_state::CACHE_HITRATES, versioned_value::cache_hitrates(""));
app_states.emplace(gms::application_state::SCHEMA_TABLES_VERSION, versioned_value(db::schema_tables::version));
app_states.emplace(gms::application_state::RPC_READY, versioned_value::cql_ready(false));
app_states.emplace(gms::application_state::VIEW_BACKLOG, versioned_value(""));
app_states.emplace(gms::application_state::SCHEMA, versioned_value::schema(_db.local().get_version()));
if (restarting_normal_node) {
// Order is important: both the CDC streams timestamp and tokens must be known when a node handles our status.
// Exception: there might be no CDC streams timestamp proposed by us if we're upgrading from a non-CDC version.
app_states.emplace(gms::application_state::TOKENS, versioned_value::tokens(my_tokens));
app_states.emplace(gms::application_state::CDC_GENERATION_ID, versioned_value::cdc_generation_id(cdc_gen_id));
app_states.emplace(gms::application_state::STATUS, versioned_value::normal(my_tokens));
}
if (!_raft_topology_change_enabled && (replacing_a_node_with_same_ip || replacing_a_node_with_diff_ip)) {
app_states.emplace(gms::application_state::TOKENS, versioned_value::tokens(bootstrap_tokens));
}
app_states.emplace(gms::application_state::SNITCH_NAME, versioned_value::snitch_name(_snitch.local()->get_name()));
app_states.emplace(gms::application_state::SHARD_COUNT, versioned_value::shard_count(smp::count));
app_states.emplace(gms::application_state::IGNORE_MSB_BITS, versioned_value::ignore_msb_bits(_db.local().get_config().murmur3_partitioner_ignore_msb_bits()));
for (auto&& s : _snitch.local()->get_app_states()) {
app_states.emplace(s.first, std::move(s.second));
}
auto schema_change_announce = _db.local().observable_schema_version().observe([this] (table_schema_version schema_version) mutable {
_migration_manager.local().passive_announce(std::move(schema_version));
});
_listeners.emplace_back(make_lw_shared(std::move(schema_change_announce)));
slogger.info("Starting up server gossip");
auto generation_number = gms::generation_type(co_await _sys_ks.local().increment_and_get_generation());
auto advertise = gms::advertise_myself(!replacing_a_node_with_same_ip);
co_await _gossiper.start_gossiping(generation_number, app_states, advertise);
if (!_raft_topology_change_enabled && should_bootstrap()) {
// Wait for NORMAL state handlers to finish for existing nodes now, so that connection dropping
// (happening at the end of `handle_state_normal`: `notify_joined`) doesn't interrupt
// group 0 joining or repair. (See #12764, #12956, #12972, #13302)
//
// But before we can do that, we must make sure that gossip sees at least one other node
// and fetches the list of peers from it; otherwise `wait_for_normal_state_handled_on_boot`
// may trivially finish without waiting for anyone.
co_await _gossiper.wait_for_live_nodes_to_show_up(2);
// Note: in Raft topology mode this is unnecessary.
// Node state changes are propagated to the cluster through explicit global barriers.
co_await wait_for_normal_state_handled_on_boot();
// NORMAL doesn't necessarily mean UP (#14042). Wait for these nodes to be UP as well
// to reduce flakiness (we need them to be UP to perform CDC generation write and for repair/streaming).
//
// This could be done in Raft topology mode as well, but the calculation of nodes to sync with
// has to be done based on topology state machine instead of gossiper as it is here;
// furthermore, the place in the code where we do this has to be different (it has to be coordinated
// by the topology coordinator after it joins the node to the cluster).
//
// We calculate nodes to wait for based on token_metadata. Previously we would use gossiper
// directly for this, but gossiper may still contain obsolete entries from 1. replaced nodes
// and 2. nodes that have changed their IPs; these entries are eventually garbage-collected,
// but here they may still be present if we're performing topology changes in quick succession.
// `token_metadata` has all host ID / token collisions resolved so in particular it doesn't contain
// these obsolete IPs. Refs: #14487, #14468
auto& tm = get_token_metadata();
auto ignore_nodes = ri
? parse_node_list(_db.local().get_config().ignore_dead_nodes_for_replace(), tm)
// TODO: specify ignore_nodes for bootstrap
: std::unordered_set<gms::inet_address>{};
std::vector<gms::inet_address> sync_nodes;
tm.get_topology().for_each_node([&] (const locator::node* np) {
auto ep = np->endpoint();
if (!ignore_nodes.contains(ep) && (!ri || ep != ri->address)) {
sync_nodes.push_back(ep);
}
});
slogger.info("Waiting for nodes {} to be alive", sync_nodes);
co_await _gossiper.wait_alive(sync_nodes, wait_for_live_nodes_timeout);
slogger.info("Nodes {} are alive", sync_nodes);
}
assert(_group0);
join_node_request_params join_params {
.host_id = _group0->load_my_id(),
.cluster_name = _db.local().get_config().cluster_name(),
.snitch_name = _db.local().get_snitch_name(),
.datacenter = _snitch.local()->get_datacenter(),
.rack = _snitch.local()->get_rack(),
.release_version = version::release(),
.num_tokens = _db.local().get_config().num_tokens(),
.shard_count = smp::count,
.ignore_msb = _db.local().get_config().murmur3_partitioner_ignore_msb_bits(),
.supported_features = boost::copy_range<std::vector<sstring>>(_feature_service.supported_feature_set()),
};
if (raft_replace_info) {
join_params.replaced_id = raft_replace_info->raft_id;
join_params.ignore_nodes = utils::split_comma_separated_list(_db.local().get_config().ignore_dead_nodes_for_replace());
}
// if the node is bootstrapped the function will do nothing since we already created group0 in main.cc
::shared_ptr<group0_handshaker> handshaker = _raft_topology_change_enabled
? ::make_shared<join_node_rpc_handshaker>(*this, join_params)
: _group0->make_legacy_handshaker(false);
co_await _group0->setup_group0(_sys_ks.local(), initial_contact_nodes, std::move(handshaker),
raft_replace_info, *this, _qp, _migration_manager.local(), _raft_topology_change_enabled);
raft::server* raft_server = co_await [this] () -> future<raft::server*> {
if (!_raft_topology_change_enabled) {
co_return nullptr;
} else if (_sys_ks.local().bootstrap_complete()) {
auto [upgrade_lock_holder, upgrade_state] = co_await _group0->client().get_group0_upgrade_state();
co_return upgrade_state == group0_upgrade_state::use_post_raft_procedures ? &_group0->group0_server() : nullptr;
} else {
auto upgrade_state = (co_await _group0->client().get_group0_upgrade_state()).second;
if (upgrade_state != group0_upgrade_state::use_post_raft_procedures) {
on_internal_error(slogger, "raft topology: cluster not upgraded to use group 0 after setup_group0");
}
co_return &_group0->group0_server();
}
} ();
co_await _gossiper.wait_for_gossip_to_settle();
// TODO: Look at the group 0 upgrade state and use it to decide whether to attach or not
if (!_raft_topology_change_enabled) {
co_await _feature_service.enable_features_on_join(_gossiper, _sys_ks.local());
}
set_mode(mode::JOINING);
if (raft_server) { // Raft is enabled. Check if we need to bootstrap ourself using raft
slogger.info("topology changes are using raft");
// start topology coordinator fiber
_raft_state_monitor = raft_state_monitor_fiber(*raft_server, sys_dist_ks);
// Need to start system_distributed_keyspace before bootstrap because bootstrapping
// process may access those tables.
supervisor::notify("starting system distributed keyspace");
co_await sys_dist_ks.invoke_on_all(&db::system_distributed_keyspace::start);
// Nodes that are not discovery leaders have their join request inserted
// on their behalf by an existing node in the cluster during the handshake.
// Discovery leaders on the other need to insert the join request themselves,
// we do that here.
co_await raft_initialize_discovery_leader(*raft_server, join_params);
auto leaving = [&] {
return _topology_state_machine._topology.left_nodes.contains(raft_server->id()) ||
(_topology_state_machine._topology.transition_nodes.contains(raft_server->id()) &&
_topology_state_machine._topology.transition_nodes[raft_server->id()].state == node_state::left_token_ring);
};
// Wait until we enter one of the final states
co_await _topology_state_machine.event.when([this, raft_server, &leaving] {
return _topology_state_machine._topology.normal_nodes.contains(raft_server->id()) || leaving();
});
if (leaving()) {
if (_sys_ks.local().bootstrap_complete()) {
throw std::runtime_error("A node that already left the cluster cannot be restarted");
} else {
throw std::runtime_error(fmt::format("{} failed. See earlier errors", raft_replace_info ? "Replace" : "Bootstrap"));
}
}
co_await update_topology_with_local_metadata(*raft_server);
// Node state is enough to know that bootstrap has completed, but to make legacy code happy
// let it know that the bootstrap is completed as well
co_await _sys_ks.local().set_bootstrap_state(db::system_keyspace::bootstrap_state::COMPLETED);
set_mode(mode::NORMAL);
if (get_token_metadata().sorted_tokens().empty()) {
auto err = ::format("join_token_ring: Sorted token in token_metadata is empty");
slogger.error("{}", err);
throw std::runtime_error(err);
}
co_await _group0->finish_setup_after_join(*this, _qp, _migration_manager.local(), _raft_topology_change_enabled);
co_return;
}
// We bootstrap if we haven't successfully bootstrapped before, as long as we are not a seed.
// If we are a seed, or if the user manually sets auto_bootstrap to false,
// we'll skip streaming data from other nodes and jump directly into the ring.
//
// The seed check allows us to skip the RING_DELAY sleep for the single-node cluster case,
// which is useful for both new users and testing.
//
// We attempted to replace this with a schema-presence check, but you need a meaningful sleep
// to get schema info from gossip which defeats the purpose. See CASSANDRA-4427 for the gory details.
if (should_bootstrap()) {
bool resume_bootstrap = _sys_ks.local().bootstrap_in_progress();
if (resume_bootstrap) {
slogger.warn("Detected previous bootstrap failure; retrying");
} else {
co_await _sys_ks.local().set_bootstrap_state(db::system_keyspace::bootstrap_state::IN_PROGRESS);
}
slogger.info("waiting for ring information");
// if our schema hasn't matched yet, keep sleeping until it does
// (post CASSANDRA-1391 we don't expect this to be necessary very often, but it doesn't hurt to be careful)
co_await wait_for_ring_to_settle();
if (!replace_address) {
auto tmptr = get_token_metadata_ptr();
if (tmptr->is_normal_token_owner(get_broadcast_address())) {
throw std::runtime_error("This node is already a member of the token ring; bootstrap aborted. (If replacing a dead node, remove the old one from the ring first.)");
}
slogger.info("getting bootstrap token");
if (resume_bootstrap) {
bootstrap_tokens = co_await _sys_ks.local().get_saved_tokens();
if (!bootstrap_tokens.empty()) {
slogger.info("Using previously saved tokens = {}", bootstrap_tokens);
} else {
bootstrap_tokens = boot_strapper::get_bootstrap_tokens(tmptr, _db.local().get_config(), dht::check_token_endpoint::yes);
}
} else {
bootstrap_tokens = boot_strapper::get_bootstrap_tokens(tmptr, _db.local().get_config(), dht::check_token_endpoint::yes);
}
} else {
if (*replace_address != get_broadcast_address()) {
// Sleep additionally to make sure that the server actually is not alive
// and giving it more time to gossip if alive.
slogger.info("Sleeping before replacing {}...", *replace_address);
co_await sleep_abortable(2 * get_ring_delay(), _abort_source);
// check for operator errors...
const auto tmptr = get_token_metadata_ptr();
for (auto token : bootstrap_tokens) {
auto existing = tmptr->get_endpoint(token);
if (existing) {
auto eps = _gossiper.get_endpoint_state_ptr(*existing);
if (eps && eps->get_update_timestamp() > gms::gossiper::clk::now() - delay) {
throw std::runtime_error("Cannot replace a live node...");
}
} else {
throw std::runtime_error(::format("Cannot replace token {} which does not exist!", token));
}
}
} else {
slogger.info("Sleeping before replacing {}...", *replace_address);
co_await sleep_abortable(get_ring_delay(), _abort_source);
}
slogger.info("Replacing a node with token(s): {}", bootstrap_tokens);
// bootstrap_tokens was previously set using tokens gossiped by the replaced node
}
co_await sys_dist_ks.invoke_on_all(&db::system_distributed_keyspace::start);
co_await mark_existing_views_as_built();
co_await _sys_ks.local().update_tokens(bootstrap_tokens);
co_await bootstrap(bootstrap_tokens, cdc_gen_id, ri);
} else {
supervisor::notify("starting system distributed keyspace");
co_await sys_dist_ks.invoke_on_all(&db::system_distributed_keyspace::start);
bootstrap_tokens = co_await _sys_ks.local().get_saved_tokens();
if (bootstrap_tokens.empty()) {
bootstrap_tokens = boot_strapper::get_bootstrap_tokens(get_token_metadata_ptr(), _db.local().get_config(), dht::check_token_endpoint::no);
co_await _sys_ks.local().update_tokens(bootstrap_tokens);
} else {
size_t num_tokens = _db.local().get_config().num_tokens();
if (bootstrap_tokens.size() != num_tokens) {
throw std::runtime_error(::format("Cannot change the number of tokens from {:d} to {:d}", bootstrap_tokens.size(), num_tokens));
} else {
slogger.info("Using saved tokens {}", bootstrap_tokens);
}
}
}
slogger.debug("Setting tokens to {}", bootstrap_tokens);
co_await mutate_token_metadata([this, &bootstrap_tokens] (mutable_token_metadata_ptr tmptr) {
// This node must know about its chosen tokens before other nodes do
// since they may start sending writes to this node after it gossips status = NORMAL.
// Therefore, in case we haven't updated _token_metadata with our tokens yet, do it now.
tmptr->update_topology(get_broadcast_address(), _snitch.local()->get_location(), locator::node::state::normal);
return tmptr->update_normal_tokens(bootstrap_tokens, get_broadcast_address());
});
if (!_sys_ks.local().bootstrap_complete()) {
// If we're not bootstrapping then we shouldn't have chosen a CDC streams timestamp yet.
assert(should_bootstrap() || !cdc_gen_id);
// Don't try rewriting CDC stream description tables.
// See cdc.md design notes, `Streams description table V1 and rewriting` section, for explanation.
co_await _sys_ks.local().cdc_set_rewritten(std::nullopt);
}
if (!cdc_gen_id) {
// If we didn't observe any CDC generation at this point, then either
// 1. we're replacing a node,
// 2. we've already bootstrapped, but are upgrading from a non-CDC version,
// 3. we're the first node, starting a fresh cluster.
// In the replacing case we won't create any CDC generation: we're not introducing any new tokens,
// so the current generation used by the cluster is fine.
// In the case of an upgrading cluster, one of the nodes is responsible for creating
// the first CDC generation. We'll check if it's us.
// Finally, if we're the first node, we'll create the first generation.
if (!is_replacing()
&& (!_sys_ks.local().bootstrap_complete()
|| cdc::should_propose_first_generation(get_broadcast_address(), _gossiper))) {
try {
cdc_gen_id = co_await _cdc_gens.local().legacy_make_new_generation(bootstrap_tokens, !is_first_node());
} catch (...) {
cdc_log.warn(
"Could not create a new CDC generation: {}. This may make it impossible to use CDC or cause performance problems."
" Use nodetool checkAndRepairCdcStreams to fix CDC.", std::current_exception());
}
}
}
// Persist the CDC streams timestamp before we persist bootstrap_state = COMPLETED.
if (cdc_gen_id) {
co_await _sys_ks.local().update_cdc_generation_id(*cdc_gen_id);
}
// If we crash now, we will choose a new CDC streams timestamp anyway (because we will also choose a new set of tokens).
// But if we crash after setting bootstrap_state = COMPLETED, we will keep using the persisted CDC streams timestamp after restarting.
co_await _sys_ks.local().set_bootstrap_state(db::system_keyspace::bootstrap_state::COMPLETED);
// At this point our local tokens and CDC streams timestamp are chosen (bootstrap_tokens, cdc_gen_id) and will not be changed.
// start participating in the ring.
co_await set_gossip_tokens(_gossiper, bootstrap_tokens, cdc_gen_id);
set_mode(mode::NORMAL);
if (get_token_metadata().sorted_tokens().empty()) {
auto err = ::format("join_token_ring: Sorted token in token_metadata is empty");
slogger.error("{}", err);
throw std::runtime_error(err);
}
assert(_group0);
co_await _group0->finish_setup_after_join(*this, _qp, _migration_manager.local(), _raft_topology_change_enabled);
co_await _cdc_gens.local().after_join(std::move(cdc_gen_id));
}
future<> storage_service::mark_existing_views_as_built() {
assert(this_shard_id() == 0);
auto views = _db.local().get_views();
co_await coroutine::parallel_for_each(views, [this] (view_ptr& view) -> future<> {
co_await _sys_ks.local().mark_view_as_built(view->ks_name(), view->cf_name());
co_await _sys_dist_ks.local().finish_view_build(view->ks_name(), view->cf_name());
});
}
std::unordered_set<gms::inet_address> storage_service::parse_node_list(sstring comma_separated_list, const token_metadata& tm) {
std::vector<sstring> ignore_nodes_strs = utils::split_comma_separated_list(std::move(comma_separated_list));
std::unordered_set<gms::inet_address> ignore_nodes;
for (const sstring& n : ignore_nodes_strs) {
try {
auto ep_and_id = tm.parse_host_id_and_endpoint(n);
ignore_nodes.insert(ep_and_id.endpoint);
} catch (...) {
throw std::runtime_error(::format("Failed to parse node list: {}: invalid node={}: {}", ignore_nodes_strs, n, std::current_exception()));
}
}
return ignore_nodes;
}
// Runs inside seastar::async context
future<> storage_service::bootstrap(std::unordered_set<token>& bootstrap_tokens, std::optional<cdc::generation_id>& cdc_gen_id, const std::optional<replacement_info>& replacement_info) {
return seastar::async([this, &bootstrap_tokens, &cdc_gen_id, &replacement_info] {
auto bootstrap_rbno = is_repair_based_node_ops_enabled(streaming::stream_reason::bootstrap);
set_mode(mode::BOOTSTRAP);
slogger.debug("bootstrap: rbno={} replacing={}", bootstrap_rbno, is_replacing());
// Wait until we know tokens of existing node before announcing replacing status.
slogger.info("Wait until local node knows tokens of peer nodes");
_gossiper.wait_for_range_setup().get();
_db.invoke_on_all([] (replica::database& db) {
for (auto& cf : db.get_non_system_column_families()) {
cf->notify_bootstrap_or_replace_start();
}
}).get();
{
int retry = 0;
while (get_token_metadata_ptr()->count_normal_token_owners() == 0) {
if (retry++ < 500) {
sleep_abortable(std::chrono::milliseconds(10), _abort_source).get();
continue;
}
// We're joining an existing cluster, so there are normal nodes in the cluster.
// We've waited for tokens to arrive.
// But we didn't see any normal token owners. Something's wrong, we cannot proceed.
throw std::runtime_error{
"Failed to learn about other nodes' tokens during bootstrap or replace. Make sure that:\n"
" - the node can contact other nodes in the cluster,\n"
" - the `ring_delay` parameter is large enough (the 30s default should be enough for small-to-middle-sized clusters),\n"
" - a node with this IP didn't recently leave the cluster. If it did, wait for some time first (the IP is quarantined),\n"
"and retry the bootstrap/replace."};
}
}
if (!replacement_info) {
// Even if we reached this point before but crashed, we will make a new CDC generation.
// It doesn't hurt: other nodes will (potentially) just do more generation switches.
// We do this because with this new attempt at bootstrapping we picked a different set of tokens.
// Update pending ranges now, so we correctly count ourselves as a pending replica
// when inserting the new CDC generation.
if (!bootstrap_rbno) {
// When is_repair_based_node_ops_enabled is true, the bootstrap node
// will use node_ops_cmd to bootstrap, node_ops_cmd will update the pending ranges.
slogger.debug("bootstrap: update pending ranges: endpoint={} bootstrap_tokens={}", get_broadcast_address(), bootstrap_tokens);
mutate_token_metadata([this, &bootstrap_tokens] (mutable_token_metadata_ptr tmptr) {
auto endpoint = get_broadcast_address();
tmptr->update_topology(endpoint, _snitch.local()->get_location(), locator::node::state::bootstrapping);
tmptr->add_bootstrap_tokens(bootstrap_tokens, endpoint);
return update_topology_change_info(std::move(tmptr), ::format("bootstrapping node {}", endpoint));
}).get();
}
// After we pick a generation timestamp, we start gossiping it, and we stick with it.
// We don't do any other generation switches (unless we crash before complecting bootstrap).
assert(!cdc_gen_id);
cdc_gen_id = _cdc_gens.local().legacy_make_new_generation(bootstrap_tokens, !is_first_node()).get0();
if (!bootstrap_rbno) {
// When is_repair_based_node_ops_enabled is true, the bootstrap node
// will use node_ops_cmd to bootstrap, bootstrapping gossip status is not needed for bootstrap.
_gossiper.add_local_application_state({
{ gms::application_state::TOKENS, versioned_value::tokens(bootstrap_tokens) },
{ gms::application_state::CDC_GENERATION_ID, versioned_value::cdc_generation_id(cdc_gen_id) },
{ gms::application_state::STATUS, versioned_value::bootstrapping(bootstrap_tokens) },
}).get();
slogger.info("sleeping {} ms for pending range setup", get_ring_delay().count());
_gossiper.wait_for_range_setup().get();
dht::boot_strapper bs(_db, _stream_manager, _abort_source, get_broadcast_address(), _snitch.local()->get_location(), bootstrap_tokens, get_token_metadata_ptr());
slogger.info("Starting to bootstrap...");
bs.bootstrap(streaming::stream_reason::bootstrap, _gossiper, null_topology_guard).get();
} else {
// Even with RBNO bootstrap we need to announce the new CDC generation immediately after it's created.
_gossiper.add_local_application_state({
{ gms::application_state::CDC_GENERATION_ID, versioned_value::cdc_generation_id(cdc_gen_id) },
}).get();
slogger.info("Starting to bootstrap...");
run_bootstrap_ops(bootstrap_tokens);
}
} else {
auto replace_addr = replacement_info->address;
auto replaced_host_id = replacement_info->host_id;
slogger.debug("Removing replaced endpoint {} from system.peers", replace_addr);
_sys_ks.local().remove_endpoint(replace_addr).get();
assert(replaced_host_id);
auto raft_id = raft::server_id{replaced_host_id.uuid()};
assert(_group0);
bool raft_available = _group0->wait_for_raft().get();
if (raft_available) {
slogger.info("Replace: removing {}/{} from group 0...", replace_addr, raft_id);
_group0->remove_from_group0(raft_id).get();
}
slogger.info("Starting to bootstrap...");
run_replace_ops(bootstrap_tokens, *replacement_info);
}
_db.invoke_on_all([] (replica::database& db) {
for (auto& cf : db.get_non_system_column_families()) {
cf->notify_bootstrap_or_replace_end();
}
}).get();
slogger.info("Bootstrap completed! for the tokens {}", bootstrap_tokens);
});
}
future<std::unordered_map<dht::token_range, inet_address_vector_replica_set>>
storage_service::get_range_to_address_map(const sstring& keyspace) const {
return get_range_to_address_map(_db.local().find_keyspace(keyspace).get_effective_replication_map());
}
future<std::unordered_map<dht::token_range, inet_address_vector_replica_set>>
storage_service::get_range_to_address_map(locator::vnode_effective_replication_map_ptr erm) const {
return get_range_to_address_map(erm, erm->get_token_metadata_ptr()->sorted_tokens());
}
// Caller is responsible to hold token_metadata valid until the returned future is resolved
future<std::unordered_map<dht::token_range, inet_address_vector_replica_set>>
storage_service::get_range_to_address_map(locator::vnode_effective_replication_map_ptr erm,
const std::vector<token>& sorted_tokens) const {
co_return co_await construct_range_to_endpoint_map(erm, co_await get_all_ranges(sorted_tokens));
}
future<> storage_service::handle_state_bootstrap(inet_address endpoint, gms::permit_id pid) {
slogger.debug("endpoint={} handle_state_bootstrap: permit_id={}", endpoint, pid);
// explicitly check for TOKENS, because a bootstrapping node might be bootstrapping in legacy mode; that is, not using vnodes and no token specified
auto tokens = get_tokens_for(endpoint);
slogger.debug("Node {} state bootstrapping, token {}", endpoint, tokens);
// if this node is present in token metadata, either we have missed intermediate states
// or the node had crashed. Print warning if needed, clear obsolete stuff and
// continue.
auto tmlock = co_await get_token_metadata_lock();
auto tmptr = co_await get_mutable_token_metadata_ptr();
if (tmptr->is_normal_token_owner(endpoint)) {
// If isLeaving is false, we have missed both LEAVING and LEFT. However, if
// isLeaving is true, we have only missed LEFT. Waiting time between completing
// leave operation and rebootstrapping is relatively short, so the latter is quite
// common (not enough time for gossip to spread). Therefore we report only the
// former in the log.
if (!tmptr->is_leaving(endpoint)) {
slogger.info("Node {} state jump to bootstrap", endpoint);
}
tmptr->remove_endpoint(endpoint);
}
tmptr->update_topology(endpoint, get_dc_rack_for(endpoint), locator::node::state::bootstrapping);
tmptr->add_bootstrap_tokens(tokens, endpoint);
tmptr->update_host_id(_gossiper.get_host_id(endpoint), endpoint);
co_await update_topology_change_info(tmptr, ::format("handle_state_bootstrap {}", endpoint));
co_await replicate_to_all_cores(std::move(tmptr));
}
future<> storage_service::handle_state_normal(inet_address endpoint, gms::permit_id pid) {
slogger.debug("endpoint={} handle_state_normal: permit_id={}", endpoint, pid);
if (_raft_topology_change_enabled) {
slogger.debug("ignore handle_state_normal since topology change are using raft");
co_return;
}
auto tokens = get_tokens_for(endpoint);
slogger.debug("Node {} state normal, token {}", endpoint, tokens);
auto tmlock = std::make_unique<token_metadata_lock>(co_await get_token_metadata_lock());
auto tmptr = co_await get_mutable_token_metadata_ptr();
if (tmptr->is_normal_token_owner(endpoint)) {
slogger.info("Node {} state jump to normal", endpoint);
}
std::unordered_set<inet_address> endpoints_to_remove;
auto do_remove_node = [&] (gms::inet_address node) {
tmptr->remove_endpoint(node);
endpoints_to_remove.insert(node);
};
// Order Matters, TM.updateHostID() should be called before TM.updateNormalToken(), (see CASSANDRA-4300).
auto host_id = _gossiper.get_host_id(endpoint);
auto existing = tmptr->get_endpoint_for_host_id_if_known(host_id);
if (existing && *existing != endpoint) {
if (*existing == get_broadcast_address()) {
slogger.warn("Not updating host ID {} for {} because it's mine", host_id, endpoint);
do_remove_node(endpoint);
} else if (_gossiper.compare_endpoint_startup(endpoint, *existing) > 0) {
slogger.warn("Host ID collision for {} between {} and {}; {} is the new owner", host_id, *existing, endpoint, endpoint);
do_remove_node(*existing);
slogger.info("Set host_id={} to be owned by node={}, existing={}", host_id, endpoint, *existing);
tmptr->update_host_id(host_id, endpoint);
} else {
slogger.warn("Host ID collision for {} between {} and {}; ignored {}", host_id, *existing, endpoint, endpoint);
do_remove_node(endpoint);
}
} else if (existing && *existing == endpoint) {
tmptr->del_replacing_endpoint(endpoint);
} else {
tmptr->del_replacing_endpoint(endpoint);
auto nodes = _gossiper.get_nodes_with_host_id(host_id);
bool left = std::any_of(nodes.begin(), nodes.end(), [this] (const gms::inet_address& node) { return _gossiper.is_left(node); });
if (left) {
slogger.info("Skip to set host_id={} to be owned by node={}, because the node is removed from the cluster, nodes {} used to own the host_id", host_id, endpoint, nodes);
_normal_state_handled_on_boot.insert(endpoint);
co_return;
}
slogger.info("Set host_id={} to be owned by node={}", host_id, endpoint);
tmptr->update_host_id(host_id, endpoint);
}
// Tokens owned by the handled endpoint.
// The endpoint broadcasts its set of chosen tokens. If a token was also chosen by another endpoint,
// the collision is resolved by assigning the token to the endpoint which started later.
std::unordered_set<token> owned_tokens;
// token_to_endpoint_map is used to track the current token owners for the purpose of removing replaced endpoints.
// when any token is replaced by a new owner, we track the existing owner in `candidates_for_removal`
// and eventually, if any candidate for removal ends up owning no tokens, it is removed from token_metadata.
std::unordered_map<token, inet_address> token_to_endpoint_map = get_token_metadata().get_token_to_endpoint();
std::unordered_set<inet_address> candidates_for_removal;
for (auto t : tokens) {
// we don't want to update if this node is responsible for the token and it has a later startup time than endpoint.
auto current = token_to_endpoint_map.find(t);
if (current == token_to_endpoint_map.end()) {
slogger.debug("handle_state_normal: New node {} at token {}", endpoint, t);
owned_tokens.insert(t);
continue;
}
auto current_owner = current->second;
if (endpoint == current_owner) {
slogger.debug("handle_state_normal: endpoint={} == current_owner={} token {}", endpoint, current_owner, t);
// set state back to normal, since the node may have tried to leave, but failed and is now back up
owned_tokens.insert(t);
} else if (_gossiper.compare_endpoint_startup(endpoint, current_owner) > 0) {
slogger.debug("handle_state_normal: endpoint={} > current_owner={}, token {}", endpoint, current_owner, t);
owned_tokens.insert(t);
slogger.info("handle_state_normal: remove endpoint={} token={}", current_owner, t);
// currentOwner is no longer current, endpoint is. Keep track of these moves, because when
// a host no longer has any tokens, we'll want to remove it.
token_to_endpoint_map.erase(current);
candidates_for_removal.insert(current_owner);
slogger.info("handle_state_normal: Nodes {} and {} have the same token {}. {} is the new owner", endpoint, current_owner, t, endpoint);
} else {
// current owner of this token is kept and endpoint attempt to own it is rejected.
// Keep track of these moves, because when a host no longer has any tokens, we'll want to remove it.
token_to_endpoint_map.erase(current);
candidates_for_removal.insert(endpoint);
slogger.info("handle_state_normal: Nodes {} and {} have the same token {}. Ignoring {}", endpoint, current_owner, t, endpoint);
}
}
// After we replace all tokens owned by current_owner
// We check for each candidate for removal if it still owns any tokens,
// and remove it if it doesn't anymore.
if (!candidates_for_removal.empty()) {
for (const auto& [t, ep] : token_to_endpoint_map) {
if (candidates_for_removal.contains(ep)) {
slogger.debug("handle_state_normal: endpoint={} still owns tokens, will not be removed", ep);
candidates_for_removal.erase(ep);
if (candidates_for_removal.empty()) {
break;
}
}
}
}
for (const auto& ep : candidates_for_removal) {
slogger.info("handle_state_normal: endpoints_to_remove endpoint={}", ep);
endpoints_to_remove.insert(ep);
}
bool is_normal_token_owner = tmptr->is_normal_token_owner(endpoint);
bool do_notify_joined = false;
if (endpoints_to_remove.contains(endpoint)) [[unlikely]] {
if (!owned_tokens.empty()) {
on_fatal_internal_error(slogger, ::format("endpoint={} is marked for removal but still owns {} tokens", endpoint, owned_tokens.size()));
}
} else {
if (owned_tokens.empty()) {
on_internal_error(slogger, ::format("endpoint={} is not marked for removal but owns no tokens", endpoint));
}
if (!is_normal_token_owner) {
do_notify_joined = true;
}
tmptr->update_topology(endpoint, get_dc_rack_for(endpoint), locator::node::state::normal);
co_await tmptr->update_normal_tokens(owned_tokens, endpoint);
}
co_await update_topology_change_info(tmptr, ::format("handle_state_normal {}", endpoint));
co_await replicate_to_all_cores(std::move(tmptr));
tmlock.reset();
for (auto ep : endpoints_to_remove) {
co_await remove_endpoint(ep, ep == endpoint ? pid : gms::null_permit_id);
}
slogger.debug("handle_state_normal: endpoint={} is_normal_token_owner={} endpoint_to_remove={} owned_tokens={}", endpoint, is_normal_token_owner, endpoints_to_remove.contains(endpoint), owned_tokens);
if (!owned_tokens.empty() && !endpoints_to_remove.count(endpoint)) {
co_await update_peer_info(endpoint);
try {
co_await _sys_ks.local().update_tokens(endpoint, owned_tokens);
} catch (...) {
slogger.error("handle_state_normal: fail to update tokens for {}: {}", endpoint, std::current_exception());
}
}
// Send joined notification only when this node was not a member prior to this
if (do_notify_joined) {
co_await notify_joined(endpoint);
}
if (slogger.is_enabled(logging::log_level::debug)) {
const auto& tm = get_token_metadata();
auto ver = tm.get_ring_version();
for (auto& x : tm.get_token_to_endpoint()) {
slogger.debug("handle_state_normal: token_metadata.ring_version={}, token={} -> endpoint={}", ver, x.first, x.second);
}
}
_normal_state_handled_on_boot.insert(endpoint);
}
future<> storage_service::handle_state_left(inet_address endpoint, std::vector<sstring> pieces, gms::permit_id pid) {
if (_raft_topology_change_enabled) {
slogger.debug("ignore handle_state_left since topology change are using raft");
co_return;
}
slogger.debug("endpoint={} handle_state_left", endpoint);
if (pieces.size() < 2) {
slogger.warn("Fail to handle_state_left endpoint={} pieces={}", endpoint, pieces);
co_return;
}
auto tokens = get_tokens_for(endpoint);
slogger.debug("Node {} state left, tokens {}", endpoint, tokens);
if (tokens.empty()) {
auto eps = _gossiper.get_endpoint_state_ptr(endpoint);
if (eps) {
slogger.warn("handle_state_left: Tokens for node={} are empty, endpoint_state={}", endpoint, *eps);
} else {
slogger.warn("handle_state_left: Couldn't find endpoint state for node={}", endpoint);
}
auto tokens_from_tm = get_token_metadata().get_tokens(endpoint);
slogger.warn("handle_state_left: Get tokens from token_metadata, node={}, tokens={}", endpoint, tokens_from_tm);
tokens = std::unordered_set<dht::token>(tokens_from_tm.begin(), tokens_from_tm.end());
}
co_await excise(tokens, endpoint, extract_expire_time(pieces), pid);
}
future<> storage_service::handle_state_removed(inet_address endpoint, std::vector<sstring> pieces, gms::permit_id pid) {
slogger.debug("endpoint={} handle_state_removed: permit_id={}", endpoint, pid);
if (endpoint == get_broadcast_address()) {
slogger.info("Received removenode gossip about myself. Is this node rejoining after an explicit removenode?");
try {
co_await drain();
} catch (...) {
slogger.error("Fail to drain: {}", std::current_exception());
throw;
}
co_return;
}
if (get_token_metadata().is_normal_token_owner(endpoint)) {
auto state = pieces[0];
auto remove_tokens = get_token_metadata().get_tokens(endpoint);
std::unordered_set<token> tmp(remove_tokens.begin(), remove_tokens.end());
co_await excise(std::move(tmp), endpoint, extract_expire_time(pieces), pid);
} else { // now that the gossiper has told us about this nonexistent member, notify the gossiper to remove it
add_expire_time_if_found(endpoint, extract_expire_time(pieces));
co_await remove_endpoint(endpoint, pid);
}
}
future<> storage_service::on_join(gms::inet_address endpoint, gms::endpoint_state_ptr ep_state, gms::permit_id pid) {
slogger.debug("endpoint={} on_join: permit_id={}", endpoint, pid);
for (const auto& e : ep_state->get_application_state_map()) {
co_await on_change(endpoint, e.first, e.second, pid);
}
}
future<> storage_service::on_alive(gms::inet_address endpoint, gms::endpoint_state_ptr state, gms::permit_id pid) {
slogger.debug("endpoint={} on_alive: permit_id={}", endpoint, pid);
bool is_normal_token_owner = get_token_metadata().is_normal_token_owner(endpoint);
if (is_normal_token_owner) {
co_await notify_up(endpoint);
} else {
auto tmlock = co_await get_token_metadata_lock();
auto tmptr = co_await get_mutable_token_metadata_ptr();
tmptr->update_topology(endpoint, get_dc_rack_for(endpoint));
co_await replicate_to_all_cores(std::move(tmptr));
}
}
future<> storage_service::before_change(gms::inet_address endpoint, gms::endpoint_state_ptr current_state, gms::application_state new_state_key, const gms::versioned_value& new_value) {
slogger.debug("endpoint={} before_change: new app_state={}, new versioned_value={}", endpoint, new_state_key, new_value);
return make_ready_future();
}
future<> storage_service::on_change(inet_address endpoint, application_state state, const versioned_value& value, gms::permit_id pid) {
slogger.debug("endpoint={} on_change: app_state={}, versioned_value={}, permit_id={}", endpoint, state, value, pid);
if (state == application_state::STATUS) {
std::vector<sstring> pieces;
boost::split(pieces, value.value(), boost::is_any_of(sstring(versioned_value::DELIMITER_STR)));
if (pieces.empty()) {
slogger.warn("Fail to split status in on_change: endpoint={}, app_state={}, value={}", endpoint, state, value);
co_return;
}
const sstring& move_name = pieces[0];
if (move_name == sstring(versioned_value::STATUS_BOOTSTRAPPING)) {
co_await handle_state_bootstrap(endpoint, pid);
} else if (move_name == sstring(versioned_value::STATUS_NORMAL) ||
move_name == sstring(versioned_value::SHUTDOWN)) {
co_await handle_state_normal(endpoint, pid);
} else if (move_name == sstring(versioned_value::REMOVED_TOKEN)) {
co_await handle_state_removed(endpoint, std::move(pieces), pid);
} else if (move_name == sstring(versioned_value::STATUS_LEFT)) {
co_await handle_state_left(endpoint, std::move(pieces), pid);
} else {
co_return; // did nothing.
}
} else {
auto ep_state = _gossiper.get_endpoint_state_ptr(endpoint);
if (!ep_state || _gossiper.is_dead_state(*ep_state)) {
slogger.debug("Ignoring state change for dead or unknown endpoint: {}", endpoint);
co_return;
}
if (get_token_metadata().is_normal_token_owner(endpoint)) {
slogger.debug("endpoint={} on_change: updating system.peers table", endpoint);
co_await do_update_system_peers_table(endpoint, state, value);
if (state == application_state::RPC_READY) {
slogger.debug("Got application_state::RPC_READY for node {}, is_cql_ready={}", endpoint, ep_state->is_cql_ready());
co_await notify_cql_change(endpoint, ep_state->is_cql_ready());
} else if (state == application_state::INTERNAL_IP) {
co_await maybe_reconnect_to_preferred_ip(endpoint, inet_address(value.value()));
}
}
}
}
future<> storage_service::maybe_reconnect_to_preferred_ip(inet_address ep, inet_address local_ip) {
if (!_snitch.local()->prefer_local()) {
co_return;
}
const auto& topo = get_token_metadata().get_topology();
if (topo.get_datacenter() == topo.get_datacenter(ep) && _messaging.local().get_preferred_ip(ep) != local_ip) {
slogger.debug("Initiated reconnect to an Internal IP {} for the {}", local_ip, ep);
co_await _messaging.invoke_on_all([ep, local_ip] (auto& local_ms) {
local_ms.cache_preferred_ip(ep, local_ip);
});
}
}
future<> storage_service::on_remove(gms::inet_address endpoint, gms::permit_id pid) {
slogger.debug("endpoint={} on_remove: permit_id={}", endpoint, pid);
auto tmlock = co_await get_token_metadata_lock();
auto tmptr = co_await get_mutable_token_metadata_ptr();
tmptr->remove_endpoint(endpoint);
co_await update_topology_change_info(tmptr, ::format("on_remove {}", endpoint));
co_await replicate_to_all_cores(std::move(tmptr));
}
future<> storage_service::on_dead(gms::inet_address endpoint, gms::endpoint_state_ptr state, gms::permit_id pid) {
slogger.debug("endpoint={} on_dead: permit_id={}", endpoint, pid);
return notify_down(endpoint);
}
future<> storage_service::on_restart(gms::inet_address endpoint, gms::endpoint_state_ptr state, gms::permit_id pid) {
slogger.debug("endpoint={} on_restart: permit_id={}", endpoint, pid);
// If we have restarted before the node was even marked down, we need to reset the connection pool
if (endpoint != get_broadcast_address() && _gossiper.is_alive(endpoint)) {
return on_dead(endpoint, state, pid);
}
return make_ready_future();
}
template <typename T>
future<> storage_service::update_table(gms::inet_address endpoint, sstring col, T value) {
try {
co_await _sys_ks.local().update_peer_info(endpoint, col, value);
} catch (...) {
slogger.error("fail to update {} for {}: {}", col, endpoint, std::current_exception());
}
}
future<> storage_service::do_update_system_peers_table(gms::inet_address endpoint, const application_state& state, const versioned_value& value) {
slogger.debug("Update system.peers table: endpoint={}, app_state={}, versioned_value={}", endpoint, state, value);
if (state == application_state::RELEASE_VERSION) {
co_await update_table(endpoint, "release_version", value.value());
} else if (state == application_state::DC) {
co_await update_table(endpoint, "data_center", value.value());
} else if (state == application_state::RACK) {
co_await update_table(endpoint, "rack", value.value());
} else if (state == application_state::INTERNAL_IP) {
auto col = sstring("preferred_ip");
inet_address ep;
try {
ep = gms::inet_address(value.value());
} catch (...) {
slogger.error("fail to update {} for {}: invalid address {}", col, endpoint, value.value());
co_return;
}
co_await update_table(endpoint, col, ep.addr());
} else if (state == application_state::RPC_ADDRESS) {
auto col = sstring("rpc_address");
inet_address ep;
try {
ep = gms::inet_address(value.value());
} catch (...) {
slogger.error("fail to update {} for {}: invalid rcpaddr {}", col, endpoint, value.value());
co_return;
}
co_await update_table(endpoint, col, ep.addr());
} else if (state == application_state::SCHEMA) {
co_await update_table(endpoint, "schema_version", utils::UUID(value.value()));
} else if (state == application_state::HOST_ID) {
co_await update_table(endpoint, "host_id", utils::UUID(value.value()));
} else if (state == application_state::SUPPORTED_FEATURES) {
co_await update_table(endpoint, "supported_features", value.value());
}
}
future<> storage_service::update_peer_info(gms::inet_address endpoint) {
slogger.debug("Update peer info: endpoint={}", endpoint);
using namespace gms;
auto ep_state = _gossiper.get_endpoint_state_ptr(endpoint);
if (!ep_state) {
co_return;
}
for (auto& entry : ep_state->get_application_state_map()) {
auto& app_state = entry.first;
auto& value = entry.second;
co_await do_update_system_peers_table(endpoint, app_state, value);
}
}
std::unordered_set<locator::token> storage_service::get_tokens_for(inet_address endpoint) {
auto tokens_string = _gossiper.get_application_state_value(endpoint, application_state::TOKENS);
slogger.trace("endpoint={}, tokens_string={}", endpoint, tokens_string);
auto ret = versioned_value::tokens_from_string(tokens_string);
slogger.trace("endpoint={}, tokens={}", endpoint, ret);
return ret;
}
std::optional<locator::endpoint_dc_rack> storage_service::get_dc_rack_for(const gms::endpoint_state& ep_state) {
auto* dc = ep_state.get_application_state_ptr(gms::application_state::DC);
auto* rack = ep_state.get_application_state_ptr(gms::application_state::RACK);
if (!dc || !rack) {
return std::nullopt;
}
return locator::endpoint_dc_rack{
.dc = dc->value(),
.rack = rack->value(),
};
}
std::optional<locator::endpoint_dc_rack> storage_service::get_dc_rack_for(inet_address endpoint) {
auto eps = _gossiper.get_endpoint_state_ptr(endpoint);
if (!eps) {
return std::nullopt;
}
return get_dc_rack_for(*eps);
}
void endpoint_lifecycle_notifier::register_subscriber(endpoint_lifecycle_subscriber* subscriber)
{
_subscribers.add(subscriber);
}
future<> endpoint_lifecycle_notifier::unregister_subscriber(endpoint_lifecycle_subscriber* subscriber) noexcept
{
return _subscribers.remove(subscriber);
}
future<> storage_service::stop_transport() {
if (!_transport_stopped.has_value()) {
promise<> stopped;
_transport_stopped = stopped.get_future();
seastar::async([this] {
slogger.info("Stop transport: starts");
slogger.debug("shutting down migration manager");
_migration_manager.invoke_on_all(&service::migration_manager::drain).get();
shutdown_protocol_servers().get();
slogger.info("Stop transport: shutdown rpc and cql server done");
_gossiper.container().invoke_on_all(&gms::gossiper::shutdown).get();
slogger.info("Stop transport: stop_gossiping done");
_messaging.invoke_on_all(&netw::messaging_service::shutdown).get();
slogger.info("Stop transport: shutdown messaging_service done");
_stream_manager.invoke_on_all(&streaming::stream_manager::shutdown).get();
slogger.info("Stop transport: shutdown stream_manager done");
slogger.info("Stop transport: done");
}).forward_to(std::move(stopped));
}
return _transport_stopped.value();
}
future<> storage_service::drain_on_shutdown() {
assert(this_shard_id() == 0);
return (_operation_mode == mode::DRAINING || _operation_mode == mode::DRAINED) ?
_drain_finished.get_future() : do_drain();
}
void storage_service::set_group0(raft_group0& group0, bool raft_topology_change_enabled) {
_group0 = &group0;
_raft_topology_change_enabled = raft_topology_change_enabled;
}
future<> storage_service::join_cluster(sharded<db::system_distributed_keyspace>& sys_dist_ks, sharded<service::storage_proxy>& proxy) {
assert(this_shard_id() == 0);
set_mode(mode::STARTING);
std::unordered_set<inet_address> loaded_endpoints;
if (_db.local().get_config().load_ring_state() && !_raft_topology_change_enabled) {
slogger.info("Loading persisted ring state");
auto loaded_tokens = co_await _sys_ks.local().load_tokens();
auto loaded_host_ids = co_await _sys_ks.local().load_host_ids();
auto loaded_dc_rack = co_await _sys_ks.local().load_dc_rack_info();
auto get_dc_rack = [&loaded_dc_rack] (inet_address ep) {
if (loaded_dc_rack.contains(ep)) {
return loaded_dc_rack[ep];
} else {
return locator::endpoint_dc_rack::default_location;
}
};
if (slogger.is_enabled(logging::log_level::debug)) {
for (auto& x : loaded_tokens) {
slogger.debug("Loaded tokens: endpoint={}, tokens={}", x.first, x.second);
}
for (auto& x : loaded_host_ids) {
slogger.debug("Loaded host_id: endpoint={}, uuid={}", x.first, x.second);
}
}
auto tmlock = co_await get_token_metadata_lock();
auto tmptr = co_await get_mutable_token_metadata_ptr();
for (auto x : loaded_tokens) {
auto ep = x.first;
auto tokens = x.second;
if (ep == get_broadcast_address()) {
// entry has been mistakenly added, delete it
co_await _sys_ks.local().remove_endpoint(ep);
} else {
tmptr->update_topology(ep, get_dc_rack(ep), locator::node::state::normal);
co_await tmptr->update_normal_tokens(tokens, ep);
if (loaded_host_ids.contains(ep)) {
tmptr->update_host_id(loaded_host_ids.at(ep), ep);
}
loaded_endpoints.insert(ep);
co_await _gossiper.add_saved_endpoint(ep);
}
}
co_await replicate_to_all_cores(std::move(tmptr));
}
// Seeds are now only used as the initial contact point nodes. If the
// loaded_endpoints are empty which means this node is a completely new
// node, we use the nodes specified in seeds as the initial contact
// point nodes, otherwise use the peer nodes persisted in system table.
auto seeds = _gossiper.get_seeds();
auto initial_contact_nodes = loaded_endpoints.empty() ?
std::unordered_set<gms::inet_address>(seeds.begin(), seeds.end()) :
loaded_endpoints;
auto loaded_peer_features = co_await _sys_ks.local().load_peer_features();
slogger.info("initial_contact_nodes={}, loaded_endpoints={}, loaded_peer_features={}",
initial_contact_nodes, loaded_endpoints, loaded_peer_features.size());
for (auto& x : loaded_peer_features) {
slogger.info("peer={}, supported_features={}", x.first, x.second);
}
co_return co_await join_token_ring(sys_dist_ks, proxy, std::move(initial_contact_nodes), std::move(loaded_endpoints), std::move(loaded_peer_features), get_ring_delay());
}
future<> storage_service::replicate_to_all_cores(mutable_token_metadata_ptr tmptr) noexcept {
assert(this_shard_id() == 0);
slogger.debug("Replicating token_metadata to all cores");
std::exception_ptr ex;
std::vector<mutable_token_metadata_ptr> pending_token_metadata_ptr;
pending_token_metadata_ptr.resize(smp::count);
std::vector<std::unordered_map<sstring, locator::vnode_effective_replication_map_ptr>> pending_effective_replication_maps;
pending_effective_replication_maps.resize(smp::count);
std::vector<std::unordered_map<table_id, locator::effective_replication_map_ptr>> pending_table_erms;
pending_table_erms.resize(smp::count);
std::unordered_set<session_id> open_sessions;
// Collect open sessions
{
auto session = _topology_state_machine._topology.session;
if (session) {
open_sessions.insert(session);
}
for (auto&& [table_id, tmap]: tmptr->tablets().all_tables()) {
for (auto&& [tid, trinfo]: tmap.transitions()) {
if (trinfo.session_id) {
auto id = session_id(trinfo.session_id);
open_sessions.insert(id);
}
}
}
}
try {
auto base_shard = this_shard_id();
pending_token_metadata_ptr[base_shard] = tmptr;
// clone a local copy of updated token_metadata on all other shards
co_await smp::invoke_on_others(base_shard, [&, tmptr] () -> future<> {
pending_token_metadata_ptr[this_shard_id()] = make_token_metadata_ptr(co_await tmptr->clone_async());
});
// Precalculate new effective_replication_map for all keyspaces
// and clone to all shards;
//
// TODO: at the moment create on shard 0 first
// but in the future we may want to use hash() % smp::count
// to evenly distribute the load.
auto& db = _db.local();
auto keyspaces = db.get_all_keyspaces();
for (auto& ks_name : keyspaces) {
auto rs = db.find_keyspace(ks_name).get_replication_strategy_ptr();
if (rs->is_per_table()) {
continue;
}
auto erm = co_await get_erm_factory().create_effective_replication_map(rs, tmptr);
pending_effective_replication_maps[base_shard].emplace(ks_name, std::move(erm));
}
co_await container().invoke_on_others([&] (storage_service& ss) -> future<> {
auto& db = ss._db.local();
for (auto& ks_name : keyspaces) {
auto rs = db.find_keyspace(ks_name).get_replication_strategy_ptr();
if (rs->is_per_table()) {
continue;
}
auto tmptr = pending_token_metadata_ptr[this_shard_id()];
auto erm = co_await ss.get_erm_factory().create_effective_replication_map(rs, std::move(tmptr));
pending_effective_replication_maps[this_shard_id()].emplace(ks_name, std::move(erm));
}
});
// Prepare per-table erms.
co_await container().invoke_on_all([&] (storage_service& ss) {
auto& db = ss._db.local();
auto tmptr = pending_token_metadata_ptr[this_shard_id()];
db.get_tables_metadata().for_each_table([&] (table_id id, lw_shared_ptr<replica::table> table) {
auto rs = db.find_keyspace(table->schema()->keypace_name()).get_replication_strategy_ptr();
locator::effective_replication_map_ptr erm;
if (auto pt_rs = rs->maybe_as_per_table()) {
erm = pt_rs->make_replication_map(id, tmptr);
} else {
erm = pending_effective_replication_maps[this_shard_id()][table->schema()->keypace_name()];
}
pending_table_erms[this_shard_id()].emplace(id, std::move(erm));
});
});
} catch (...) {
ex = std::current_exception();
}
// Rollback on metadata replication error
if (ex) {
try {
co_await smp::invoke_on_all([&] () -> future<> {
auto tmptr = std::move(pending_token_metadata_ptr[this_shard_id()]);
auto erms = std::move(pending_effective_replication_maps[this_shard_id()]);
auto table_erms = std::move(pending_table_erms[this_shard_id()]);
co_await utils::clear_gently(erms);
co_await utils::clear_gently(tmptr);
});
} catch (...) {
slogger.warn("Failure to reset pending token_metadata in cleanup path: {}. Ignored.", std::current_exception());
}
std::rethrow_exception(std::move(ex));
}
// Apply changes on all shards
try {
co_await container().invoke_on_all([&] (storage_service& ss) {
ss._shared_token_metadata.set(std::move(pending_token_metadata_ptr[this_shard_id()]));
auto& db = ss._db.local();
auto& erms = pending_effective_replication_maps[this_shard_id()];
for (auto it = erms.begin(); it != erms.end(); ) {
auto& ks = db.find_keyspace(it->first);
ks.update_effective_replication_map(std::move(it->second));
it = erms.erase(it);
}
auto& table_erms = pending_table_erms[this_shard_id()];
for (auto it = table_erms.begin(); it != table_erms.end(); ) {
auto& cf = db.find_column_family(it->first);
cf.update_effective_replication_map(std::move(it->second));
it = table_erms.erase(it);
}
auto& session_mgr = get_topology_session_manager();
session_mgr.initiate_close_of_sessions_except(open_sessions);
for (auto id : open_sessions) {
session_mgr.create_session(id);
}
});
} catch (...) {
// applying the changes on all shards should never fail
// it will end up in an inconsistent state that we can't recover from.
slogger.error("Failed to apply token_metadata changes: {}. Aborting.", std::current_exception());
abort();
}
}
future<> storage_service::stop() {
co_await uninit_messaging_service();
// make sure nobody uses the semaphore
node_ops_signal_abort(std::nullopt);
_listeners.clear();
co_await _async_gate.close();
co_await std::move(_node_ops_abort_thread);
}
future<> storage_service::wait_for_group0_stop() {
_group0_as.request_abort();
_topology_state_machine.event.broken(make_exception_ptr(abort_requested_exception()));
co_await std::move(_raft_state_monitor);
}
future<> storage_service::check_for_endpoint_collision(std::unordered_set<gms::inet_address> initial_contact_nodes, const std::unordered_map<gms::inet_address, sstring>& loaded_peer_features) {
slogger.debug("Starting shadow gossip round to check for endpoint collision");
return seastar::async([this, initial_contact_nodes, loaded_peer_features] {
auto t = gms::gossiper::clk::now();
bool found_bootstrapping_node = false;
auto local_features = _feature_service.supported_feature_set();
do {
slogger.info("Performing gossip shadow round");
_gossiper.do_shadow_round(initial_contact_nodes, gms::gossiper::mandatory::yes).get();
if (!_raft_topology_change_enabled) {
_gossiper.check_knows_remote_features(local_features, loaded_peer_features);
}
_gossiper.check_snitch_name_matches(_snitch.local()->get_name());
auto addr = get_broadcast_address();
if (!_gossiper.is_safe_for_bootstrap(addr)) {
throw std::runtime_error(::format("A node with address {} already exists, cancelling join. "
"Use replace_address if you want to replace this node.", addr));
}
if (_db.local().get_config().consistent_rangemovement() &&
// Raft is responsible for consistency, so in case it is enable no need to check here
!_raft_topology_change_enabled) {
found_bootstrapping_node = false;
for (const auto& addr : _gossiper.get_endpoints()) {
auto state = _gossiper.get_gossip_status(addr);
if (state == sstring(versioned_value::STATUS_UNKNOWN)) {
throw std::runtime_error(::format("Node {} has gossip status=UNKNOWN. Try fixing it before adding new node to the cluster.", addr));
}
slogger.debug("Checking bootstrapping/leaving/moving nodes: node={}, status={} (check_for_endpoint_collision)", addr, state);
if (state == sstring(versioned_value::STATUS_BOOTSTRAPPING)) {
if (gms::gossiper::clk::now() > t + std::chrono::seconds(60)) {
throw std::runtime_error("Other bootstrapping/leaving/moving nodes detected, cannot bootstrap while consistent_rangemovement is true (check_for_endpoint_collision)");
} else {
sstring saved_state(state);
_gossiper.goto_shadow_round();
_gossiper.reset_endpoint_state_map().get();
found_bootstrapping_node = true;
auto elapsed = std::chrono::duration_cast<std::chrono::seconds>(gms::gossiper::clk::now() - t).count();
slogger.info("Checking bootstrapping/leaving/moving nodes: node={}, status={}, sleep 1 second and check again ({} seconds elapsed) (check_for_endpoint_collision)", addr, saved_state, elapsed);
sleep_abortable(std::chrono::seconds(1), _abort_source).get();
break;
}
}
}
}
} while (found_bootstrapping_node);
slogger.info("Checking bootstrapping/leaving/moving nodes: ok (check_for_endpoint_collision)");
_gossiper.reset_endpoint_state_map().get();
});
}
future<> storage_service::remove_endpoint(inet_address endpoint, gms::permit_id pid) {
co_await _gossiper.remove_endpoint(endpoint, pid);
try {
co_await _sys_ks.local().remove_endpoint(endpoint);
} catch (...) {
slogger.error("fail to remove endpoint={}: {}", endpoint, std::current_exception());
}
}
future<storage_service::replacement_info>
storage_service::prepare_replacement_info(std::unordered_set<gms::inet_address> initial_contact_nodes, const std::unordered_map<gms::inet_address, sstring>& loaded_peer_features) {
locator::host_id replace_host_id;
gms::inet_address replace_address;
auto& cfg = _db.local().get_config();
if (!cfg.replace_node_first_boot().empty()) {
replace_host_id = locator::host_id(utils::UUID(cfg.replace_node_first_boot()));
} else if (!cfg.replace_address_first_boot().empty()) {
replace_address = gms::inet_address(cfg.replace_address_first_boot());
slogger.warn("The replace_address_first_boot={} option is deprecated. Please use the replace_node_first_boot option", replace_address);
} else if (!cfg.replace_address().empty()) {
replace_address = gms::inet_address(cfg.replace_address());
slogger.warn("The replace_address={} option is deprecated. Please use the replace_node_first_boot option", replace_address);
} else {
on_internal_error(slogger, "No replace_node or replace_address configuration options found");
}
slogger.info("Gathering node replacement information for {}/{}", replace_host_id, replace_address);
auto seeds = _gossiper.get_seeds();
if (seeds.size() == 1 && seeds.contains(replace_address)) {
throw std::runtime_error(::format("Cannot replace_address {} because no seed node is up", replace_address));
}
// make magic happen
slogger.info("Performing gossip shadow round");
co_await _gossiper.do_shadow_round(initial_contact_nodes, gms::gossiper::mandatory::yes);
if (!_raft_topology_change_enabled) {
auto local_features = _feature_service.supported_feature_set();
_gossiper.check_knows_remote_features(local_features, loaded_peer_features);
}
// now that we've gossiped at least once, we should be able to find the node we're replacing
if (replace_host_id) {
auto nodes = _gossiper.get_nodes_with_host_id(replace_host_id);
if (nodes.empty()) {
throw std::runtime_error(::format("Replaced node with Host ID {} not found", replace_host_id));
}
if (nodes.size() > 1) {
throw std::runtime_error(::format("Found multiple nodes with Host ID {}: {}", replace_host_id, nodes));
}
replace_address = *nodes.begin();
}
auto state = _gossiper.get_endpoint_state_ptr(replace_address);
if (!state) {
throw std::runtime_error(::format("Cannot replace_address {} because it doesn't exist in gossip", replace_address));
}
// Reject to replace a node that has left the ring
auto status = _gossiper.get_gossip_status(replace_address);
if (status == gms::versioned_value::STATUS_LEFT || status == gms::versioned_value::REMOVED_TOKEN) {
throw std::runtime_error(::format("Cannot replace_address {} because it has left the ring, status={}", replace_address, status));
}
std::unordered_set<dht::token> tokens;
if (!_raft_topology_change_enabled) {
tokens = get_tokens_for(replace_address);
if (tokens.empty()) {
throw std::runtime_error(::format("Could not find tokens for {} to replace", replace_address));
}
}
auto dc_rack = get_dc_rack_for(replace_address).value_or(locator::endpoint_dc_rack::default_location);
if (!replace_host_id) {
replace_host_id = _gossiper.get_host_id(replace_address);
}
slogger.info("Host {}/{} is replacing {}/{}", get_token_metadata().get_my_id(), get_broadcast_address(), replace_host_id, replace_address);
co_await _gossiper.reset_endpoint_state_map();
co_return replacement_info {
.tokens = std::move(tokens),
.dc_rack = std::move(dc_rack),
.host_id = std::move(replace_host_id),
.address = replace_address,
};
}
future<std::map<gms::inet_address, float>> storage_service::get_ownership() {
return run_with_no_api_lock([] (storage_service& ss) {
const auto& tm = ss.get_token_metadata();
auto token_map = dht::token::describe_ownership(tm.sorted_tokens());
// describeOwnership returns tokens in an unspecified order, let's re-order them
std::map<gms::inet_address, float> ownership;
for (auto entry : token_map) {
gms::inet_address endpoint = tm.get_endpoint(entry.first).value();
auto token_ownership = entry.second;
ownership[endpoint] += token_ownership;
}
return ownership;
});
}
future<std::map<gms::inet_address, float>> storage_service::effective_ownership(sstring keyspace_name) {
return run_with_no_api_lock([keyspace_name] (storage_service& ss) mutable -> future<std::map<gms::inet_address, float>> {
locator::vnode_effective_replication_map_ptr erm;
if (keyspace_name != "") {
//find throws no such keyspace if it is missing
const replica::keyspace& ks = ss._db.local().find_keyspace(keyspace_name);
// This is ugly, but it follows origin
auto&& rs = ks.get_replication_strategy(); // clang complains about typeid(ks.get_replication_strategy());
if (typeid(rs) == typeid(locator::local_strategy)) {
throw std::runtime_error("Ownership values for keyspaces with LocalStrategy are meaningless");
}
erm = ks.get_effective_replication_map();
} else {
auto non_system_keyspaces = ss._db.local().get_non_system_keyspaces();
//system_traces is a non-system keyspace however it needs to be counted as one for this process
size_t special_table_count = 0;
if (std::find(non_system_keyspaces.begin(), non_system_keyspaces.end(), "system_traces") !=
non_system_keyspaces.end()) {
special_table_count += 1;
}
if (non_system_keyspaces.size() > special_table_count) {
throw std::runtime_error("Non-system keyspaces don't have the same replication settings, effective ownership information is meaningless");
}
keyspace_name = "system_traces";
const auto& ks = ss._db.local().find_keyspace(keyspace_name);
erm = ks.get_effective_replication_map();
}
// The following loops seems computationally heavy, but it's not as bad.
// The upper two simply iterate over all the endpoints by iterating over all the
// DC and all the instances in each DC.
//
// The call for get_range_for_endpoint is done once per endpoint
const auto& tm = *erm->get_token_metadata_ptr();
const auto token_ownership = dht::token::describe_ownership(tm.sorted_tokens());
const auto datacenter_endpoints = tm.get_topology().get_datacenter_endpoints();
std::map<gms::inet_address, float> final_ownership;
for (const auto& [dc, endpoints_map] : datacenter_endpoints) {
for (auto endpoint : endpoints_map) {
// calculate the ownership with replication and add the endpoint to the final ownership map
try {
float ownership = 0.0f;
auto ranges = ss.get_ranges_for_endpoint(erm, endpoint);
for (auto& r : ranges) {
// get_ranges_for_endpoint will unwrap the first range.
// With t0 t1 t2 t3, the first range (t3,t0] will be split
// as (min,t0] and (t3,max]. Skippping the range (t3,max]
// we will get the correct ownership number as if the first
// range were not split.
if (!r.end()) {
continue;
}
auto end_token = r.end()->value();
auto loc = token_ownership.find(end_token);
if (loc != token_ownership.end()) {
ownership += loc->second;
}
}
final_ownership[endpoint] = ownership;
} catch (replica::no_such_keyspace&) {
// In case ss.get_ranges_for_endpoint(keyspace_name, endpoint) is not found, just mark it as zero and continue
final_ownership[endpoint] = 0;
}
}
}
co_return final_ownership;
});
}
void storage_service::set_mode(mode m) {
if (m != _operation_mode) {
slogger.info("entering {} mode", m);
_operation_mode = m;
} else {
// This shouldn't happen, but it's too much for an assert,
// so -- just emit a warning in the hope that it will be
// noticed, reported and fixed
slogger.warn("re-entering {} mode", m);
}
}
sstring storage_service::get_release_version() {
return version::release();
}
sstring storage_service::get_schema_version() {
return _db.local().get_version().to_sstring();
}
static constexpr auto UNREACHABLE = "UNREACHABLE";
future<std::unordered_map<sstring, std::vector<sstring>>> storage_service::describe_schema_versions() {
auto live_hosts = _gossiper.get_live_members();
std::unordered_map<sstring, std::vector<sstring>> results;
netw::messaging_service& ms = _messaging.local();
return map_reduce(std::move(live_hosts), [&ms] (auto host) {
auto f0 = ms.send_schema_check(netw::msg_addr{ host, 0 });
return std::move(f0).then_wrapped([host] (auto f) {
if (f.failed()) {
f.ignore_ready_future();
return std::pair<gms::inet_address, std::optional<table_schema_version>>(host, std::nullopt);
}
return std::pair<gms::inet_address, std::optional<table_schema_version>>(host, f.get0());
});
}, std::move(results), [] (auto results, auto host_and_version) {
auto version = host_and_version.second ? host_and_version.second->to_sstring() : UNREACHABLE;
results.try_emplace(version).first->second.emplace_back(host_and_version.first.to_sstring());
return results;
}).then([this] (auto results) {
// we're done: the results map is ready to return to the client. the rest is just debug logging:
auto it_unreachable = results.find(UNREACHABLE);
if (it_unreachable != results.end()) {
slogger.debug("Hosts not in agreement. Didn't get a response from everybody: {}", fmt::join(it_unreachable->second, ","));
}
auto my_version = get_schema_version();
for (auto&& entry : results) {
// check for version disagreement. log the hosts that don't agree.
if (entry.first == UNREACHABLE || entry.first == my_version) {
continue;
}
for (auto&& host : entry.second) {
slogger.debug("{} disagrees ({})", host, entry.first);
}
}
if (results.size() == 1) {
slogger.debug("Schemas are in agreement.");
}
return results;
});
};
future<storage_service::mode> storage_service::get_operation_mode() {
return run_with_no_api_lock([] (storage_service& ss) {
return make_ready_future<mode>(ss._operation_mode);
});
}
future<bool> storage_service::is_gossip_running() {
return run_with_no_api_lock([] (storage_service& ss) {
return ss._gossiper.is_enabled();
});
}
future<> storage_service::start_gossiping() {
return run_with_api_lock(sstring("start_gossiping"), [] (storage_service& ss) -> future<> {
if (!ss._gossiper.is_enabled()) {
slogger.warn("Starting gossip by operator request");
co_await ss._gossiper.container().invoke_on_all(&gms::gossiper::start);
bool should_stop_gossiper = false; // undo action
try {
auto cdc_gen_ts = co_await ss._sys_ks.local().get_cdc_generation_id();
if (!cdc_gen_ts) {
cdc_log.warn("CDC generation timestamp missing when starting gossip");
}
co_await set_gossip_tokens(ss._gossiper,
co_await ss._sys_ks.local().get_local_tokens(),
cdc_gen_ts);
ss._gossiper.force_newer_generation();
co_await ss._gossiper.start_gossiping(gms::get_generation_number());
} catch (...) {
should_stop_gossiper = true;
}
if (should_stop_gossiper) {
co_await ss._gossiper.container().invoke_on_all(&gms::gossiper::stop);
}
}
});
}
future<> storage_service::stop_gossiping() {
return run_with_api_lock(sstring("stop_gossiping"), [] (storage_service& ss) {
if (ss._gossiper.is_enabled()) {
slogger.warn("Stopping gossip by operator request");
return ss._gossiper.container().invoke_on_all(&gms::gossiper::stop);
}
return make_ready_future<>();
});
}
static
void on_streaming_finished() {
utils::get_local_injector().inject("storage_service_streaming_sleep3", std::chrono::seconds{3}).get();
}
future<> storage_service::raft_decommission() {
auto& raft_server = _group0->group0_server();
auto disengage_shutdown_promise = defer([this] {
_shutdown_request_promise = std::nullopt;
});
while (true) {
auto guard = co_await _group0->client().start_operation(&_group0_as);
auto it = _topology_state_machine._topology.find(raft_server.id());
if (!it) {
throw std::runtime_error(::format("local node {} is not a member of the cluster", raft_server.id()));
}
const auto& rs = it->second;
if (rs.state != node_state::normal) {
throw std::runtime_error(::format("local node is not in the normal state (current state: {})", rs.state));
}
if (_topology_state_machine._topology.normal_nodes.size() == 1) {
throw std::runtime_error("Cannot decommission last node in the cluster");
}
slogger.info("raft topology: request decommission for: {}", raft_server.id());
topology_mutation_builder builder(guard.write_timestamp());
builder.with_node(raft_server.id())
.set("topology_request", topology_request::leave);
topology_change change{{builder.build()}};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard, ::format("decommission: request decommission for {}", raft_server.id()));
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard), &_group0_as);
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: decommission: concurrent operation is detected, retrying.");
continue;
}
break;
}
// Wait for the coordinator to tell us to shut down or for decomission request to disappear
bool abort_wait = false;
auto f1 = _shutdown_request_promise.emplace().get_future().then([this, &abort_wait] {
// shutdown was signalled, abort the wait for the topology event
abort_wait = true;
_topology_state_machine.event.broadcast();
});
auto f2 = _topology_state_machine.event.wait([this, &raft_server, &abort_wait] {
if (abort_wait) {
return true; // the wait is aborted
}
// Wait for decommission request to be removed, but node stay as normal which means decommission failed
auto it = _topology_state_machine._topology.find(raft_server.id());
if (it->second.state == node_state::normal) {
auto rit = _topology_state_machine._topology.requests.find(raft_server.id());
if (rit == _topology_state_machine._topology.requests.end() || rit->second != topology_request::leave) {
_shutdown_request_promise->set_exception(std::runtime_error("Decommission failure"));
return true; // node is normal, but leave request is gone. It means decommission failed
}
}
return false;
});
auto res = co_await when_all(std::move(f1), std::move(f2));
if (!std::get<0>(res).failed()) {
// Need to set it otherwise gossiper will try to send shutdown on exit
co_await _gossiper.add_local_application_state({{ gms::application_state::STATUS, gms::versioned_value::left({}, _gossiper.now().time_since_epoch().count()) }});
} else {
constexpr auto err = "Decommission failed. See earlier errors";
slogger.error(err);
throw std::runtime_error(err);
}
}
future<> storage_service::decommission() {
return run_with_api_lock(sstring("decommission"), [] (storage_service& ss) {
return seastar::async([&ss] {
std::exception_ptr leave_group0_ex;
if (ss._raft_topology_change_enabled) {
ss.raft_decommission().get();
} else {
bool left_token_ring = false;
auto uuid = node_ops_id::create_random_id();
auto& db = ss._db.local();
node_ops_ctl ctl(ss, node_ops_cmd::decommission_prepare, ss.get_token_metadata().get_my_id(), ss.get_broadcast_address());
auto stop_ctl = deferred_stop(ctl);
// Step 1: Decide who needs to sync data
// TODO: wire ignore_nodes provided by user
ctl.start("decommission");
uuid = ctl.uuid();
auto endpoint = ctl.endpoint;
const auto& tmptr = ctl.tmptr;
if (!tmptr->is_normal_token_owner(endpoint)) {
throw std::runtime_error("local node is not a member of the token ring yet");
}
// We assume that we're a member of group 0 if we're in decommission()` and Raft is enabled.
// We have no way to check that we're not a member: attempting to perform group 0 operations
// would simply hang in that case, the leader would refuse to talk to us.
// If we aren't a member then we shouldn't be here anyway, since it means that either
// an earlier decommission finished (leave_group0 is the last operation in decommission)
// or that we were removed using `removenode`.
//
// For handling failure scenarios such as a group 0 member that is not a token ring member,
// there's `removenode`.
auto temp = tmptr->clone_after_all_left().get0();
auto num_tokens_after_all_left = temp.sorted_tokens().size();
temp.clear_gently().get();
if (num_tokens_after_all_left < 2) {
throw std::runtime_error("no other normal nodes in the ring; decommission would be pointless");
}
if (ss._operation_mode != mode::NORMAL) {
throw std::runtime_error(::format("Node in {} state; wait for status to become normal or restart", ss._operation_mode));
}
ss.update_topology_change_info(::format("decommission {}", endpoint)).get();
auto non_system_keyspaces = db.get_non_local_vnode_based_strategy_keyspaces();
for (const auto& keyspace_name : non_system_keyspaces) {
if (ss._db.local().find_keyspace(keyspace_name).get_effective_replication_map()->has_pending_ranges(ss.get_broadcast_address())) {
throw std::runtime_error("data is currently moving to this node; unable to leave the ring");
}
}
slogger.info("DECOMMISSIONING: starts");
ctl.req.leaving_nodes = std::list<gms::inet_address>{endpoint};
assert(ss._group0);
bool raft_available = ss._group0->wait_for_raft().get();
try {
// Step 2: Start heartbeat updater
ctl.start_heartbeat_updater(node_ops_cmd::decommission_heartbeat);
// Step 3: Prepare to sync data
ctl.prepare(node_ops_cmd::decommission_prepare).get();
// Step 4: Start to sync data
slogger.info("DECOMMISSIONING: unbootstrap starts");
ss.unbootstrap().get();
on_streaming_finished();
slogger.info("DECOMMISSIONING: unbootstrap done");
// Step 5: Become a group 0 non-voter before leaving the token ring.
//
// Thanks to this, even if we fail after leaving the token ring but before leaving group 0,
// group 0's availability won't be reduced.
if (raft_available) {
slogger.info("decommission[{}]: becoming a group 0 non-voter", uuid);
ss._group0->become_nonvoter().get();
slogger.info("decommission[{}]: became a group 0 non-voter", uuid);
}
// Step 6: Verify that other nodes didn't abort in the meantime.
// See https://github.com/scylladb/scylladb/issues/12989.
ctl.query_pending_op().get();
// Step 7: Leave the token ring
slogger.info("decommission[{}]: leaving token ring", uuid);
ss.leave_ring().get();
left_token_ring = true;
slogger.info("decommission[{}]: left token ring", uuid);
// Step 8: Finish token movement
ctl.done(node_ops_cmd::decommission_done).get();
} catch (...) {
ctl.abort_on_error(node_ops_cmd::decommission_abort, std::current_exception()).get();
}
// Step 8: Leave group 0
//
// If the node failed to leave the token ring, don't remove it from group 0
// --- hence the `left_token_ring` check.
try {
utils::get_local_injector().inject("decommission_fail_before_leave_group0",
[] { throw std::runtime_error("decommission_fail_before_leave_group0"); });
if (raft_available && left_token_ring) {
slogger.info("decommission[{}]: leaving Raft group 0", uuid);
assert(ss._group0);
ss._group0->leave_group0().get();
slogger.info("decommission[{}]: left Raft group 0", uuid);
}
} catch (...) {
// Even though leave_group0 failed, we will finish decommission and shut down everything.
// There's nothing smarter we could do. We should not continue operating in this broken
// state (we're not a member of the token ring any more).
//
// If we didn't manage to leave group 0, we will stay as a non-voter
// (which is not too bad - non-voters at least do not reduce group 0's availability).
// It's possible to remove the garbage member using `removenode`.
slogger.error(
"decommission[{}]: FAILED when trying to leave Raft group 0: \"{}\". This node"
" is no longer a member of the token ring, so it will finish shutting down its services."
" It may still be a member of Raft group 0. To remove it, shut it down and use `removenode`."
" Consult the `decommission` and `removenode` documentation for more details.",
uuid, std::current_exception());
leave_group0_ex = std::current_exception();
}
}
ss.stop_transport().get();
slogger.info("DECOMMISSIONING: stopped transport");
ss.get_batchlog_manager().invoke_on_all([] (auto& bm) {
return bm.drain();
}).get();
slogger.info("DECOMMISSIONING: stop batchlog_manager done");
// StageManager.shutdownNow();
ss._sys_ks.local().set_bootstrap_state(db::system_keyspace::bootstrap_state::DECOMMISSIONED).get();
slogger.info("DECOMMISSIONING: set_bootstrap_state done");
ss.set_mode(mode::DECOMMISSIONED);
if (leave_group0_ex) {
std::rethrow_exception(leave_group0_ex);
}
slogger.info("DECOMMISSIONING: done");
// let op be responsible for killing the process
});
});
}
// Runs inside seastar::async context
void storage_service::run_bootstrap_ops(std::unordered_set<token>& bootstrap_tokens) {
node_ops_ctl ctl(*this, node_ops_cmd::bootstrap_prepare, get_token_metadata().get_my_id(), get_broadcast_address());
auto stop_ctl = deferred_stop(ctl);
const auto& uuid = ctl.uuid();
// Step 1: Decide who needs to sync data for bootstrap operation
// TODO: Specify ignore_nodes
ctl.start("bootstrap");
auto start_time = std::chrono::steady_clock::now();
for (;;) {
ctl.sync_nodes.insert(get_broadcast_address());
// Step 2: Wait until no pending node operations
std::unordered_map<gms::inet_address, std::list<node_ops_id>> pending_ops;
auto req = node_ops_cmd_request(node_ops_cmd::query_pending_ops, uuid);
parallel_for_each(ctl.sync_nodes, [this, req, uuid, &pending_ops] (const gms::inet_address& node) {
return _messaging.local().send_node_ops_cmd(netw::msg_addr(node), req).then([uuid, node, &pending_ops] (node_ops_cmd_response resp) {
slogger.debug("bootstrap[{}]: Got query_pending_ops response from node={}, resp.pending_ops={}", uuid, node, resp.pending_ops);
if (!resp.pending_ops.empty()) {
pending_ops.emplace(node, resp.pending_ops);
}
return make_ready_future<>();
});
}).handle_exception([uuid] (std::exception_ptr ep) {
slogger.warn("bootstrap[{}]: Failed to query_pending_ops : {}", uuid, ep);
}).get();
if (pending_ops.empty()) {
break;
} else {
if (std::chrono::steady_clock::now() > start_time + std::chrono::seconds(60)) {
throw std::runtime_error(::format("bootstrap[{}]: Found pending node ops = {}, reject bootstrap", uuid, pending_ops));
}
slogger.warn("bootstrap[{}]: Found pending node ops = {}, sleep 5 seconds and check again", uuid, pending_ops);
sleep_abortable(std::chrono::seconds(5), _abort_source).get();
ctl.refresh_sync_nodes();
// the bootstrapping node will be added back when we loop
}
}
auto tokens = std::list<dht::token>(bootstrap_tokens.begin(), bootstrap_tokens.end());
ctl.req.bootstrap_nodes = {
{get_broadcast_address(), tokens},
};
try {
// Step 2: Start heartbeat updater
ctl.start_heartbeat_updater(node_ops_cmd::bootstrap_heartbeat);
// Step 3: Prepare to sync data
ctl.prepare(node_ops_cmd::bootstrap_prepare).get();
// Step 5: Sync data for bootstrap
_repair.local().bootstrap_with_repair(get_token_metadata_ptr(), bootstrap_tokens).get();
on_streaming_finished();
// Step 6: Finish
ctl.done(node_ops_cmd::bootstrap_done).get();
} catch (...) {
ctl.abort_on_error(node_ops_cmd::bootstrap_abort, std::current_exception()).get();
}
}
// Runs inside seastar::async context
void storage_service::run_replace_ops(std::unordered_set<token>& bootstrap_tokens, replacement_info replace_info) {
node_ops_ctl ctl(*this, node_ops_cmd::replace_prepare, replace_info.host_id, replace_info.address);
auto stop_ctl = deferred_stop(ctl);
const auto& uuid = ctl.uuid();
gms::inet_address replace_address = replace_info.address;
ctl.ignore_nodes = parse_node_list(_db.local().get_config().ignore_dead_nodes_for_replace(), *ctl.tmptr);
// Step 1: Decide who needs to sync data for replace operation
// The replacing node is not a normal token owner yet
// Add it back explicitly after checking all other nodes.
ctl.start("replace", [&] (gms::inet_address node) {
return node != replace_address;
});
ctl.sync_nodes.insert(get_broadcast_address());
auto sync_nodes_generations = _gossiper.get_generation_for_nodes(ctl.sync_nodes).get();
// Map existing nodes to replacing nodes
ctl.req.replace_nodes = {
{replace_address, get_broadcast_address()},
};
try {
// Step 2: Start heartbeat updater
ctl.start_heartbeat_updater(node_ops_cmd::replace_heartbeat);
// Step 3: Prepare to sync data
ctl.prepare(node_ops_cmd::replace_prepare).get();
// Step 4: Allow nodes in sync_nodes list to mark the replacing node as alive
_gossiper.advertise_to_nodes(sync_nodes_generations).get();
slogger.info("replace[{}]: Allow nodes={} to mark replacing node={} as alive", uuid, ctl.sync_nodes, get_broadcast_address());
// Step 5: Wait for nodes to finish marking the replacing node as live
ctl.send_to_all(node_ops_cmd::replace_prepare_mark_alive).get();
// Step 6: Update pending ranges on nodes
ctl.send_to_all(node_ops_cmd::replace_prepare_pending_ranges).get();
// Step 7: Sync data for replace
if (is_repair_based_node_ops_enabled(streaming::stream_reason::replace)) {
slogger.info("replace[{}]: Using repair based node ops to sync data", uuid);
_repair.local().replace_with_repair(get_token_metadata_ptr(), bootstrap_tokens, ctl.ignore_nodes).get();
} else {
slogger.info("replace[{}]: Using streaming based node ops to sync data", uuid);
dht::boot_strapper bs(_db, _stream_manager, _abort_source, get_broadcast_address(), _snitch.local()->get_location(), bootstrap_tokens, get_token_metadata_ptr());
bs.bootstrap(streaming::stream_reason::replace, _gossiper, null_topology_guard, replace_address).get();
}
on_streaming_finished();
// Step 8: Finish
ctl.done(node_ops_cmd::replace_done).get();
// Allow any nodes to mark the replacing node as alive
_gossiper.advertise_to_nodes({}).get();
slogger.info("replace[{}]: Allow any nodes to mark replacing node={} as alive", uuid, get_broadcast_address());
} catch (...) {
// we need to revert the effect of prepare verb the replace ops is failed
ctl.abort_on_error(node_ops_cmd::replace_abort, std::current_exception()).get();
}
}
future<> storage_service::raft_removenode(locator::host_id host_id, std::list<locator::host_id_or_endpoint> ignore_nodes_params) {
auto id = raft::server_id{host_id.uuid()};
while (true) {
auto guard = co_await _group0->client().start_operation(&_group0_as);
auto it = _topology_state_machine._topology.find(id);
if (!it) {
throw std::runtime_error(::format("removenode: host id {} is not found in the cluster", host_id));
}
auto& rs = it->second; // not usable after yield
if (rs.state != node_state::normal) {
throw std::runtime_error(::format("removenode: node {} is in '{}' state. Wait for it to be in 'normal' state", id, rs.state));
}
const auto& am = _group0->address_map();
auto ip = am.find(id);
if (!ip) {
// What to do if there is no mapping? Wait and retry?
on_fatal_internal_error(slogger, ::format("Remove node cannot find a mapping from node id {} to its ip", id));
}
if (_gossiper.is_alive(*ip)) {
const std::string message = ::format(
"removenode: Rejected removenode operation for node {} ip {} "
"the node being removed is alive, maybe you should use decommission instead?",
id, *ip);
slogger.warn("raft topology {}", message);
throw std::runtime_error(message);
}
auto ignored_ids = find_raft_nodes_from_hoeps(ignore_nodes_params);
slogger.info("raft topology: request removenode for: {}, ignored nodes: {}", id, ignored_ids);
topology_mutation_builder builder(guard.write_timestamp());
builder.with_node(id)
.set("ignore_nodes", ignored_ids)
.set("topology_request", topology_request::remove);
topology_change change{{builder.build()}};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard, ::format("removenode: request remove for {}", id));
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard), &_group0_as);
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: removenode: concurrent operation is detected, retrying.");
continue;
}
break;
}
bool left = false;
co_await _topology_state_machine.event.when([this, id, &left] {
// Wait for this node to move to state left which means that removenode completed
// or wait for removenode request to be removed, but node stay as normal which means removenode failed
auto it = _topology_state_machine._topology.find(id);
if (!it) {
left = true;
return true; // node either left or on the way
}
if (it->second.state == node_state::normal) {
auto rit = _topology_state_machine._topology.requests.find(id);
if (rit == _topology_state_machine._topology.requests.end() || rit->second != topology_request::remove) {
return true; // node is normal, but remove request is gone. It means removenode failed
}
}
return false;
});
if (left) {
try {
co_await _group0->remove_from_raft_config(id);
} catch (raft::not_a_member&) {
slogger.info("raft topology removenode: already removed from the raft config by the topology coordinator");
}
} else {
constexpr auto err = "Removenode failed. See earlier errors";
slogger.error(err);
throw std::runtime_error(err);
}
}
future<> storage_service::removenode(locator::host_id host_id, std::list<locator::host_id_or_endpoint> ignore_nodes_params) {
return run_with_api_lock(sstring("removenode"), [host_id, ignore_nodes_params = std::move(ignore_nodes_params)] (storage_service& ss) mutable {
return seastar::async([&ss, host_id, ignore_nodes_params = std::move(ignore_nodes_params)] () mutable {
if (ss._raft_topology_change_enabled) {
ss.raft_removenode(host_id, std::move(ignore_nodes_params)).get();
return;
}
node_ops_ctl ctl(ss, node_ops_cmd::removenode_prepare, host_id, gms::inet_address());
auto stop_ctl = deferred_stop(ctl);
auto uuid = ctl.uuid();
const auto& tmptr = ctl.tmptr;
auto endpoint_opt = tmptr->get_endpoint_for_host_id_if_known(host_id);
assert(ss._group0);
auto raft_id = raft::server_id{host_id.uuid()};
bool raft_available = ss._group0->wait_for_raft().get();
bool is_group0_member = raft_available && ss._group0->is_member(raft_id, false);
if (!endpoint_opt && !is_group0_member) {
throw std::runtime_error(::format("removenode[{}]: Node {} not found in the cluster", uuid, host_id));
}
// If endpoint_opt is engaged, the node is a member of the token ring.
// is_group0_member indicates whether the node is a member of Raft group 0.
// A node might be a member of group 0 but not a member of the token ring, e.g. due to a
// previously failed removenode/decommission. The code is written to handle this
// situation. Parts related to removing this node from the token ring are conditioned on
// endpoint_opt, while parts related to removing from group 0 are conditioned on
// is_group0_member.
if (endpoint_opt && ss._gossiper.is_alive(*endpoint_opt)) {
const std::string message = ::format(
"removenode[{}]: Rejected removenode operation (node={}); "
"the node being removed is alive, maybe you should use decommission instead?",
uuid, *endpoint_opt);
slogger.warn(std::string_view(message));
throw std::runtime_error(message);
}
for (auto& hoep : ignore_nodes_params) {
hoep.resolve(*tmptr);
ctl.ignore_nodes.insert(hoep.endpoint);
}
bool removed_from_token_ring = !endpoint_opt;
if (endpoint_opt) {
auto endpoint = *endpoint_opt;
ctl.endpoint = endpoint;
// Step 1: Make the node a group 0 non-voter before removing it from the token ring.
//
// Thanks to this, even if we fail after removing the node from the token ring
// but before removing it group 0, group 0's availability won't be reduced.
if (is_group0_member && ss._group0->is_member(raft_id, true)) {
slogger.info("removenode[{}]: making node {} a non-voter in group 0", uuid, raft_id);
ss._group0->make_nonvoter(raft_id).get();
slogger.info("removenode[{}]: made node {} a non-voter in group 0", uuid, raft_id);
}
// Step 2: Decide who needs to sync data
//
// By default, we require all nodes in the cluster to participate
// the removenode operation and sync data if needed. We fail the
// removenode operation if any of them is down or fails.
//
// If the user want the removenode operation to succeed even if some of the nodes
// are not available, the user has to explicitly pass a list of
// node that can be skipped for the operation.
ctl.start("removenode", [&] (gms::inet_address node) {
return node != endpoint;
});
auto tokens = tmptr->get_tokens(endpoint);
try {
// Step 3: Start heartbeat updater
ctl.start_heartbeat_updater(node_ops_cmd::removenode_heartbeat);
// Step 4: Prepare to sync data
ctl.req.leaving_nodes = {endpoint};
ctl.prepare(node_ops_cmd::removenode_prepare).get();
// Step 5: Start to sync data
ctl.send_to_all(node_ops_cmd::removenode_sync_data).get();
on_streaming_finished();
// Step 6: Finish token movement
ctl.done(node_ops_cmd::removenode_done).get();
// Step 7: Announce the node has left
slogger.info("removenode[{}]: Advertising that the node left the ring", uuid);
auto permit = ss._gossiper.lock_endpoint(endpoint, gms::null_permit_id).get();
const auto& pid = permit.id();
ss._gossiper.advertise_token_removed(endpoint, host_id, pid).get();
std::unordered_set<token> tmp(tokens.begin(), tokens.end());
ss.excise(std::move(tmp), endpoint, pid).get();
removed_from_token_ring = true;
slogger.info("removenode[{}]: Finished removing the node from the ring", uuid);
} catch (...) {
// we need to revert the effect of prepare verb the removenode ops is failed
ctl.abort_on_error(node_ops_cmd::removenode_abort, std::current_exception()).get();
}
}
// Step 8: Remove the node from group 0
//
// If the node was a token ring member but we failed to remove it,
// don't remove it from group 0 -- hence the `removed_from_token_ring` check.
try {
utils::get_local_injector().inject("removenode_fail_before_remove_from_group0",
[] { throw std::runtime_error("removenode_fail_before_remove_from_group0"); });
if (is_group0_member && removed_from_token_ring) {
slogger.info("removenode[{}]: removing node {} from Raft group 0", uuid, raft_id);
ss._group0->remove_from_group0(raft_id).get();
slogger.info("removenode[{}]: removed node {} from Raft group 0", uuid, raft_id);
}
} catch (...) {
slogger.error(
"removenode[{}]: FAILED when trying to remove the node from Raft group 0: \"{}\". The node"
" is no longer a member of the token ring, but it may still be a member of Raft group 0."
" Please retry `removenode`. Consult the `removenode` documentation for more details.",
uuid, std::current_exception());
throw;
}
slogger.info("removenode[{}]: Finished removenode operation, host id={}", uuid, host_id);
});
});
}
future<> storage_service::check_and_repair_cdc_streams() {
assert(this_shard_id() == 0);
if (!_cdc_gens.local_is_initialized()) {
return make_exception_future<>(std::runtime_error("CDC generation service not initialized yet"));
}
if (_raft_topology_change_enabled) {
return raft_check_and_repair_cdc_streams();
}
return _cdc_gens.local().check_and_repair_cdc_streams();
}
class node_ops_meta_data {
node_ops_id _ops_uuid;
gms::inet_address _coordinator;
std::function<future<> ()> _abort;
shared_ptr<abort_source> _abort_source;
std::function<void ()> _signal;
shared_ptr<node_ops_info> _ops;
seastar::timer<lowres_clock> _watchdog;
std::chrono::seconds _watchdog_interval;
public:
explicit node_ops_meta_data(
node_ops_id ops_uuid,
gms::inet_address coordinator,
std::list<gms::inet_address> ignore_nodes,
std::chrono::seconds watchdog_interval,
std::function<future<> ()> abort_func,
std::function<void ()> signal_func);
shared_ptr<node_ops_info> get_ops_info();
shared_ptr<abort_source> get_abort_source();
future<> abort();
void update_watchdog();
void cancel_watchdog();
};
void storage_service::node_ops_cmd_check(gms::inet_address coordinator, const node_ops_cmd_request& req) {
auto ops_uuids = boost::copy_range<std::vector<node_ops_id>>(_node_ops| boost::adaptors::map_keys);
std::string msg;
if (req.cmd == node_ops_cmd::removenode_prepare || req.cmd == node_ops_cmd::replace_prepare ||
req.cmd == node_ops_cmd::decommission_prepare || req.cmd == node_ops_cmd::bootstrap_prepare) {
// Peer node wants to start a new node operation. Make sure no pending node operation is in progress.
if (!_node_ops.empty()) {
msg = ::format("node_ops_cmd_check: Node {} rejected node_ops_cmd={} from node={} with ops_uuid={}, pending_node_ops={}, pending node ops is in progress",
get_broadcast_address(), req.cmd, coordinator, req.ops_uuid, ops_uuids);
}
} else if (req.cmd == node_ops_cmd::decommission_heartbeat || req.cmd == node_ops_cmd::removenode_heartbeat ||
req.cmd == node_ops_cmd::replace_heartbeat || req.cmd == node_ops_cmd::bootstrap_heartbeat) {
// We allow node_ops_cmd heartbeat to be sent before prepare cmd
} else {
if (ops_uuids.size() == 1 && ops_uuids.front() == req.ops_uuid) {
// Check is good, since we know this ops_uuid and this is the only ops_uuid we are working on.
} else if (ops_uuids.size() == 0) {
// The ops_uuid received is unknown. Fail the request.
msg = ::format("node_ops_cmd_check: Node {} rejected node_ops_cmd={} from node={} with ops_uuid={}, pending_node_ops={}, the node ops is unknown",
get_broadcast_address(), req.cmd, coordinator, req.ops_uuid, ops_uuids);
} else {
// Other node ops is in progress. Fail the request.
msg = ::format("node_ops_cmd_check: Node {} rejected node_ops_cmd={} from node={} with ops_uuid={}, pending_node_ops={}, pending node ops is in progress",
get_broadcast_address(), req.cmd, coordinator, req.ops_uuid, ops_uuids);
}
}
if (!msg.empty()) {
slogger.warn("{}", msg);
throw std::runtime_error(msg);
}
}
void storage_service::on_node_ops_registered(node_ops_id ops_uuid) {
utils::get_local_injector().inject("storage_service_nodeops_prepare_handler_sleep3", std::chrono::seconds{3}).get();
utils::get_local_injector().inject("storage_service_nodeops_abort_after_1s", [this, ops_uuid] {
(void)with_gate(_async_gate, [this, ops_uuid] {
return seastar::sleep_abortable(std::chrono::seconds(1), _abort_source).then([this, ops_uuid] {
node_ops_signal_abort(ops_uuid);
});
});
});
}
void storage_service::node_ops_insert(node_ops_id ops_uuid,
gms::inet_address coordinator,
std::list<inet_address> ignore_nodes,
std::function<future<>()> abort_func) {
auto watchdog_interval = std::chrono::seconds(_db.local().get_config().nodeops_watchdog_timeout_seconds());
auto meta = node_ops_meta_data(ops_uuid, coordinator, std::move(ignore_nodes), watchdog_interval, std::move(abort_func),
[this, ops_uuid]() mutable { node_ops_signal_abort(ops_uuid); });
_node_ops.emplace(ops_uuid, std::move(meta));
on_node_ops_registered(ops_uuid);
}
future<node_ops_cmd_response> storage_service::node_ops_cmd_handler(gms::inet_address coordinator, node_ops_cmd_request req) {
return seastar::async([this, coordinator, req = std::move(req)] () mutable {
auto ops_uuid = req.ops_uuid;
auto topo_guard = null_topology_guard;
slogger.debug("node_ops_cmd_handler cmd={}, ops_uuid={}", req.cmd, ops_uuid);
if (req.cmd == node_ops_cmd::query_pending_ops) {
bool ok = true;
auto ops_uuids = boost::copy_range<std::list<node_ops_id>>(_node_ops| boost::adaptors::map_keys);
node_ops_cmd_response resp(ok, ops_uuids);
slogger.debug("node_ops_cmd_handler: Got query_pending_ops request from {}, pending_ops={}", coordinator, ops_uuids);
return resp;
} else if (req.cmd == node_ops_cmd::repair_updater) {
slogger.debug("repair[{}]: Got repair_updater request from {}", ops_uuid, coordinator);
_db.invoke_on_all([coordinator, ops_uuid, tables = req.repair_tables] (replica::database &db) {
for (const auto& table_id : tables) {
try {
auto& table = db.find_column_family(table_id);
table.update_off_strategy_trigger();
slogger.debug("repair[{}]: Updated off_strategy_trigger for table {}.{} by node {}",
ops_uuid, table.schema()->ks_name(), table.schema()->cf_name(), coordinator);
} catch (replica::no_such_column_family&) {
// The table could be dropped by user, ignore it.
} catch (...) {
throw;
}
}
}).get();
bool ok = true;
return node_ops_cmd_response(ok);
}
node_ops_cmd_check(coordinator, req);
if (req.cmd == node_ops_cmd::removenode_prepare) {
if (req.leaving_nodes.size() > 1) {
auto msg = ::format("removenode[{}]: Could not removenode more than one node at a time: leaving_nodes={}", req.ops_uuid, req.leaving_nodes);
slogger.warn("{}", msg);
throw std::runtime_error(msg);
}
mutate_token_metadata([coordinator, &req, this] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& node : req.leaving_nodes) {
slogger.info("removenode[{}]: Added node={} as leaving node, coordinator={}", req.ops_uuid, node, coordinator);
tmptr->add_leaving_endpoint(node);
}
return update_topology_change_info(tmptr, ::format("removenode {}", req.leaving_nodes));
}).get();
node_ops_insert(ops_uuid, coordinator, std::move(req.ignore_nodes), [this, coordinator, req = std::move(req)] () mutable {
return mutate_token_metadata([this, coordinator, req = std::move(req)] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& node : req.leaving_nodes) {
slogger.info("removenode[{}]: Removed node={} as leaving node, coordinator={}", req.ops_uuid, node, coordinator);
tmptr->del_leaving_endpoint(node);
}
return update_topology_change_info(tmptr, ::format("removenode {}", req.leaving_nodes));
});
});
} else if (req.cmd == node_ops_cmd::removenode_heartbeat) {
slogger.debug("removenode[{}]: Updated heartbeat from coordinator={}", req.ops_uuid, coordinator);
node_ops_update_heartbeat(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::removenode_done) {
slogger.info("removenode[{}]: Marked ops done from coordinator={}", req.ops_uuid, coordinator);
node_ops_done(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::removenode_sync_data) {
auto it = _node_ops.find(ops_uuid);
if (it == _node_ops.end()) {
throw std::runtime_error(::format("removenode[{}]: Can not find ops_uuid={}", ops_uuid, ops_uuid));
}
auto ops = it->second.get_ops_info();
auto as = it->second.get_abort_source();
for (auto& node : req.leaving_nodes) {
if (is_repair_based_node_ops_enabled(streaming::stream_reason::removenode)) {
slogger.info("removenode[{}]: Started to sync data for removing node={} using repair, coordinator={}", req.ops_uuid, node, coordinator);
_repair.local().removenode_with_repair(get_token_metadata_ptr(), node, ops).get();
} else {
slogger.info("removenode[{}]: Started to sync data for removing node={} using stream, coordinator={}", req.ops_uuid, node, coordinator);
removenode_with_stream(node, topo_guard, as).get();
}
}
} else if (req.cmd == node_ops_cmd::removenode_abort) {
node_ops_abort(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::decommission_prepare) {
utils::get_local_injector().inject(
"storage_service_decommission_prepare_handler_sleep", std::chrono::milliseconds{1500}).get();
if (req.leaving_nodes.size() > 1) {
auto msg = ::format("decommission[{}]: Could not decommission more than one node at a time: leaving_nodes={}", req.ops_uuid, req.leaving_nodes);
slogger.warn("{}", msg);
throw std::runtime_error(msg);
}
mutate_token_metadata([coordinator, &req, this] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& node : req.leaving_nodes) {
slogger.info("decommission[{}]: Added node={} as leaving node, coordinator={}", req.ops_uuid, node, coordinator);
tmptr->add_leaving_endpoint(node);
}
return update_topology_change_info(tmptr, ::format("decommission {}", req.leaving_nodes));
}).get();
node_ops_insert(ops_uuid, coordinator, std::move(req.ignore_nodes), [this, coordinator, req = std::move(req)] () mutable {
return mutate_token_metadata([this, coordinator, req = std::move(req)] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& node : req.leaving_nodes) {
slogger.info("decommission[{}]: Removed node={} as leaving node, coordinator={}", req.ops_uuid, node, coordinator);
tmptr->del_leaving_endpoint(node);
}
return update_topology_change_info(tmptr, ::format("decommission {}", req.leaving_nodes));
});
});
} else if (req.cmd == node_ops_cmd::decommission_heartbeat) {
slogger.debug("decommission[{}]: Updated heartbeat from coordinator={}", req.ops_uuid, coordinator);
node_ops_update_heartbeat(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::decommission_done) {
bool check_again = false;
auto start_time = std::chrono::steady_clock::now();
slogger.info("decommission[{}]: Started to check if nodes={} have left the cluster, coordinator={}", req.ops_uuid, req.leaving_nodes, coordinator);
do {
check_again = false;
for (auto& node : req.leaving_nodes) {
auto tmptr = get_token_metadata_ptr();
if (tmptr->is_normal_token_owner(node)) {
check_again = true;
if (std::chrono::steady_clock::now() > start_time + std::chrono::seconds(60)) {
auto msg = ::format("decommission[{}]: Node {} is still in the cluster", req.ops_uuid, node);
throw std::runtime_error(msg);
}
slogger.warn("decommission[{}]: Node {} is still in the cluster, sleep and check again", req.ops_uuid, node);
sleep_abortable(std::chrono::milliseconds(500), _abort_source).get();
break;
}
}
} while (check_again);
slogger.info("decommission[{}]: Finished to check if nodes={} have left the cluster, coordinator={}", req.ops_uuid, req.leaving_nodes, coordinator);
slogger.info("decommission[{}]: Marked ops done from coordinator={}", req.ops_uuid, coordinator);
slogger.debug("Triggering off-strategy compaction for all non-system tables on decommission completion");
_db.invoke_on_all([](replica::database &db) {
for (auto& table : db.get_non_system_column_families()) {
table->trigger_offstrategy_compaction();
}
}).get();
node_ops_done(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::decommission_abort) {
node_ops_abort(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::replace_prepare) {
// Mark the replacing node as replacing
if (req.replace_nodes.size() > 1) {
auto msg = ::format("replace[{}]: Could not replace more than one node at a time: replace_nodes={}", req.ops_uuid, req.replace_nodes);
slogger.warn("{}", msg);
throw std::runtime_error(msg);
}
mutate_token_metadata([coordinator, &req, this] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& x: req.replace_nodes) {
auto existing_node = x.first;
auto replacing_node = x.second;
slogger.info("replace[{}]: Added replacing_node={} to replace existing_node={}, coordinator={}", req.ops_uuid, replacing_node, existing_node, coordinator);
tmptr->update_topology(replacing_node, get_dc_rack_for(replacing_node), locator::node::state::replacing);
tmptr->add_replacing_endpoint(existing_node, replacing_node);
}
return make_ready_future<>();
}).get();
node_ops_insert(ops_uuid, coordinator, std::move(req.ignore_nodes), [this, coordinator, req = std::move(req)] () mutable {
return mutate_token_metadata([this, coordinator, req = std::move(req)] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& x: req.replace_nodes) {
auto existing_node = x.first;
auto replacing_node = x.second;
slogger.info("replace[{}]: Removed replacing_node={} to replace existing_node={}, coordinator={}", req.ops_uuid, replacing_node, existing_node, coordinator);
tmptr->del_replacing_endpoint(existing_node);
}
return update_topology_change_info(tmptr, ::format("replace {}", req.replace_nodes));
});
});
} else if (req.cmd == node_ops_cmd::replace_prepare_mark_alive) {
// Wait for local node has marked replacing node as alive
auto nodes = boost::copy_range<std::vector<inet_address>>(req.replace_nodes| boost::adaptors::map_values);
try {
_gossiper.wait_alive(nodes, std::chrono::milliseconds(120 * 1000)).get();
} catch (...) {
slogger.warn("replace[{}]: Failed to wait for marking replacing node as up, replace_nodes={}: {}",
req.ops_uuid, req.replace_nodes, std::current_exception());
throw;
}
} else if (req.cmd == node_ops_cmd::replace_prepare_pending_ranges) {
// Update the pending_ranges for the replacing node
slogger.debug("replace[{}]: Updated pending_ranges from coordinator={}", req.ops_uuid, coordinator);
mutate_token_metadata([&req, this] (mutable_token_metadata_ptr tmptr) mutable {
return update_topology_change_info(tmptr, ::format("replace {}", req.replace_nodes));
}).get();
} else if (req.cmd == node_ops_cmd::replace_heartbeat) {
slogger.debug("replace[{}]: Updated heartbeat from coordinator={}", req.ops_uuid, coordinator);
node_ops_update_heartbeat(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::replace_done) {
slogger.info("replace[{}]: Marked ops done from coordinator={}", req.ops_uuid, coordinator);
node_ops_done(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::replace_abort) {
node_ops_abort(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::bootstrap_prepare) {
// Mark the bootstrap node as bootstrapping
if (req.bootstrap_nodes.size() > 1) {
auto msg = ::format("bootstrap[{}]: Could not bootstrap more than one node at a time: bootstrap_nodes={}", req.ops_uuid, req.bootstrap_nodes);
slogger.warn("{}", msg);
throw std::runtime_error(msg);
}
mutate_token_metadata([coordinator, &req, this] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& x: req.bootstrap_nodes) {
auto& endpoint = x.first;
auto tokens = std::unordered_set<dht::token>(x.second.begin(), x.second.end());
slogger.info("bootstrap[{}]: Added node={} as bootstrap, coordinator={}", req.ops_uuid, endpoint, coordinator);
tmptr->update_topology(endpoint, get_dc_rack_for(endpoint), locator::node::state::bootstrapping);
tmptr->add_bootstrap_tokens(tokens, endpoint);
}
return update_topology_change_info(tmptr, ::format("bootstrap {}", req.bootstrap_nodes));
}).get();
node_ops_insert(ops_uuid, coordinator, std::move(req.ignore_nodes), [this, coordinator, req = std::move(req)] () mutable {
return mutate_token_metadata([this, coordinator, req = std::move(req)] (mutable_token_metadata_ptr tmptr) mutable {
for (auto& x: req.bootstrap_nodes) {
auto& endpoint = x.first;
auto tokens = std::unordered_set<dht::token>(x.second.begin(), x.second.end());
slogger.info("bootstrap[{}]: Removed node={} as bootstrap, coordinator={}", req.ops_uuid, endpoint, coordinator);
tmptr->remove_bootstrap_tokens(tokens);
}
return update_topology_change_info(tmptr, ::format("bootstrap {}", req.bootstrap_nodes));
});
});
} else if (req.cmd == node_ops_cmd::bootstrap_heartbeat) {
slogger.debug("bootstrap[{}]: Updated heartbeat from coordinator={}", req.ops_uuid, coordinator);
node_ops_update_heartbeat(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::bootstrap_done) {
slogger.info("bootstrap[{}]: Marked ops done from coordinator={}", req.ops_uuid, coordinator);
node_ops_done(ops_uuid).get();
} else if (req.cmd == node_ops_cmd::bootstrap_abort) {
node_ops_abort(ops_uuid).get();
} else {
auto msg = ::format("node_ops_cmd_handler: ops_uuid={}, unknown cmd={}", req.ops_uuid, req.cmd);
slogger.warn("{}", msg);
throw std::runtime_error(msg);
}
bool ok = true;
node_ops_cmd_response resp(ok);
return resp;
});
}
future<> storage_service::reload_schema() {
// Flush memtables and clear cache so that we use the same state we would after node restart
// to rule out potential discrepancies which could stem from merging with memtable/cache readers.
co_await replica::database::flush_keyspace_on_all_shards(_db, db::schema_tables::v3::NAME);
co_await replica::database::drop_cache_for_keyspace_on_all_shards(_db, db::schema_tables::v3::NAME);
co_await _migration_manager.invoke_on(0, [] (auto& mm) {
return mm.reload_schema();
});
}
future<> storage_service::drain() {
return run_with_api_lock(sstring("drain"), [] (storage_service& ss) {
if (ss._operation_mode == mode::DRAINED) {
slogger.warn("Cannot drain node (did it already happen?)");
return make_ready_future<>();
}
ss.set_mode(mode::DRAINING);
return ss.do_drain().then([&ss] {
ss._drain_finished.set_value();
ss.set_mode(mode::DRAINED);
});
});
}
future<> storage_service::do_drain() {
co_await stop_transport();
co_await tracing::tracing::tracing_instance().invoke_on_all(&tracing::tracing::shutdown);
co_await get_batchlog_manager().invoke_on_all([] (auto& bm) {
return bm.drain();
});
co_await _db.invoke_on_all(&replica::database::drain);
co_await _sys_ks.invoke_on_all(&db::system_keyspace::shutdown);
co_await _repair.invoke_on_all(&repair_service::shutdown);
}
future<> storage_service::raft_rebuild(sstring source_dc) {
auto& raft_server = _group0->group0_server();
while (true) {
auto guard = co_await _group0->client().start_operation(&_group0_as);
auto it = _topology_state_machine._topology.find(raft_server.id());
if (!it) {
throw std::runtime_error(::format("local node {} is not a member of the cluster", raft_server.id()));
}
const auto& rs = it->second;
if (rs.state != node_state::normal) {
throw std::runtime_error(::format("local node is not in the normal state (current state: {})", rs.state));
}
if (_topology_state_machine._topology.normal_nodes.size() == 1) {
throw std::runtime_error("Cannot rebuild a single node");
}
slogger.info("raft topology: request rebuild for: {}", raft_server.id());
topology_mutation_builder builder(guard.write_timestamp());
builder.with_node(raft_server.id())
.set("topology_request", topology_request::rebuild)
.set("rebuild_option", source_dc);
topology_change change{{builder.build()}};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard, ::format("rebuild: request rebuild for {} ({})", raft_server.id(), source_dc));
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard), &_group0_as);
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: rebuild: concurrent operation is detected, retrying.");
continue;
}
break;
}
// Wait until rebuild completes. We know it completes when the request parameter is empty
co_await _topology_state_machine.event.when([this, &raft_server] {
return !_topology_state_machine._topology.req_param.contains(raft_server.id());
});
}
future<> storage_service::raft_check_and_repair_cdc_streams() {
std::optional<cdc::generation_id_v2> curr_gen;
while (true) {
slogger.info("raft topology: request check_and_repair_cdc_streams, refreshing topology");
auto guard = co_await _group0->client().start_operation(&_group0_as);
auto curr_req = _topology_state_machine._topology.global_request;
if (curr_req && *curr_req != global_topology_request::new_cdc_generation) {
// FIXME: replace this with a queue
throw std::runtime_error{
"check_and_repair_cdc_streams: a different topology request is already pending, try again later"};
}
curr_gen = _topology_state_machine._topology.current_cdc_generation_id;
if (!curr_gen) {
slogger.error("check_and_repair_cdc_streams: no current CDC generation, requesting a new one.");
} else {
auto gen = co_await _sys_ks.local().read_cdc_generation(curr_gen->id);
if (cdc::is_cdc_generation_optimal(gen, get_token_metadata())) {
cdc_log.info("CDC generation {} does not need repair", curr_gen);
co_return;
}
cdc_log.info("CDC generation {} needs repair, requesting a new one", curr_gen);
}
topology_mutation_builder builder(guard.write_timestamp());
builder.set_global_topology_request(global_topology_request::new_cdc_generation);
topology_change change{{builder.build()}};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard,
::format("request check+repair CDC generation from {}", _group0->group0_server().id()));
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard), &_group0_as);
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: request check+repair CDC: concurrent operation is detected, retrying.");
continue;
}
break;
}
// Wait until the current CDC generation changes.
co_await _topology_state_machine.event.when([this, &curr_gen] {
return curr_gen != _topology_state_machine._topology.current_cdc_generation_id;
});
}
future<> storage_service::rebuild(sstring source_dc) {
return run_with_api_lock(sstring("rebuild"), [source_dc] (storage_service& ss) -> future<> {
if (ss._raft_topology_change_enabled) {
co_await ss.raft_rebuild(source_dc);
} else {
slogger.info("rebuild from dc: {}", source_dc == "" ? "(any dc)" : source_dc);
auto tmptr = ss.get_token_metadata_ptr();
if (ss.is_repair_based_node_ops_enabled(streaming::stream_reason::rebuild)) {
co_await ss._repair.local().rebuild_with_repair(tmptr, std::move(source_dc));
} else {
auto streamer = make_lw_shared<dht::range_streamer>(ss._db, ss._stream_manager, tmptr, ss._abort_source,
ss.get_broadcast_address(), ss._snitch.local()->get_location(), "Rebuild", streaming::stream_reason::rebuild, null_topology_guard);
streamer->add_source_filter(std::make_unique<dht::range_streamer::failure_detector_source_filter>(ss._gossiper.get_unreachable_members()));
if (source_dc != "") {
streamer->add_source_filter(std::make_unique<dht::range_streamer::single_datacenter_filter>(source_dc));
}
auto ks_erms = ss._db.local().get_non_local_strategy_keyspaces_erms();
for (const auto& [keyspace_name, erm] : ks_erms) {
co_await streamer->add_ranges(keyspace_name, erm, ss.get_ranges_for_endpoint(erm, ss.get_broadcast_address()), ss._gossiper, false);
}
try {
co_await streamer->stream_async();
slogger.info("Streaming for rebuild successful");
} catch (...) {
auto ep = std::current_exception();
// This is used exclusively through JMX, so log the full trace but only throw a simple RTE
slogger.warn("Error while rebuilding node: {}", ep);
std::rethrow_exception(std::move(ep));
}
}
}
});
}
int32_t storage_service::get_exception_count() {
// FIXME
// We return 0 for no exceptions, it should probably be
// replaced by some general exception handling that would count
// the unhandled exceptions.
//return (int)StorageMetrics.exceptions.count();
return 0;
}
future<std::unordered_multimap<dht::token_range, inet_address>>
storage_service::get_changed_ranges_for_leaving(locator::vnode_effective_replication_map_ptr erm, inet_address endpoint) {
// First get all ranges the leaving endpoint is responsible for
auto ranges = get_ranges_for_endpoint(erm, endpoint);
slogger.debug("Node {} ranges [{}]", endpoint, ranges);
std::unordered_map<dht::token_range, inet_address_vector_replica_set> current_replica_endpoints;
// Find (for each range) all nodes that store replicas for these ranges as well
for (auto& r : ranges) {
auto end_token = r.end() ? r.end()->value() : dht::maximum_token();
auto eps = erm->get_natural_endpoints(end_token);
current_replica_endpoints.emplace(r, std::move(eps));
co_await coroutine::maybe_yield();
}
auto temp = co_await get_token_metadata_ptr()->clone_after_all_left();
// endpoint might or might not be 'leaving'. If it was not leaving (that is, removenode
// command was used), it is still present in temp and must be removed.
if (temp.is_normal_token_owner(endpoint)) {
temp.remove_endpoint(endpoint);
}
std::unordered_multimap<dht::token_range, inet_address> changed_ranges;
// Go through the ranges and for each range check who will be
// storing replicas for these ranges when the leaving endpoint
// is gone. Whoever is present in newReplicaEndpoints list, but
// not in the currentReplicaEndpoints list, will be needing the
// range.
const auto& rs = erm->get_replication_strategy();
for (auto& r : ranges) {
auto end_token = r.end() ? r.end()->value() : dht::maximum_token();
auto new_replica_endpoints = co_await rs.calculate_natural_endpoints(end_token, temp);
auto rg = current_replica_endpoints.equal_range(r);
for (auto it = rg.first; it != rg.second; it++) {
const dht::token_range& range_ = it->first;
inet_address_vector_replica_set& current_eps = it->second;
slogger.debug("range={}, current_replica_endpoints={}, new_replica_endpoints={}", range_, current_eps, new_replica_endpoints);
for (auto ep : it->second) {
auto beg = new_replica_endpoints.begin();
auto end = new_replica_endpoints.end();
new_replica_endpoints.erase(std::remove(beg, end, ep), end);
}
}
if (slogger.is_enabled(logging::log_level::debug)) {
if (new_replica_endpoints.empty()) {
slogger.debug("Range {} already in all replicas", r);
} else {
slogger.debug("Range {} will be responsibility of {}", r, new_replica_endpoints);
}
}
for (auto& ep : new_replica_endpoints) {
changed_ranges.emplace(r, ep);
}
// Replication strategy doesn't necessarily yield in calculate_natural_endpoints.
// E.g. everywhere_replication_strategy
co_await coroutine::maybe_yield();
}
co_await temp.clear_gently();
co_return changed_ranges;
}
future<> storage_service::unbootstrap() {
slogger.info("Started batchlog replay for decommission");
co_await get_batchlog_manager().local().do_batch_log_replay();
slogger.info("Finished batchlog replay for decommission");
if (is_repair_based_node_ops_enabled(streaming::stream_reason::decommission)) {
co_await _repair.local().decommission_with_repair(get_token_metadata_ptr());
} else {
std::unordered_map<sstring, std::unordered_multimap<dht::token_range, inet_address>> ranges_to_stream;
auto ks_erms = _db.local().get_non_local_strategy_keyspaces_erms();
for (const auto& [keyspace_name, erm] : ks_erms) {
auto ranges_mm = co_await get_changed_ranges_for_leaving(erm, get_broadcast_address());
if (slogger.is_enabled(logging::log_level::debug)) {
std::vector<range<token>> ranges;
for (auto& x : ranges_mm) {
ranges.push_back(x.first);
}
slogger.debug("Ranges needing transfer for keyspace={} are [{}]", keyspace_name, ranges);
}
ranges_to_stream.emplace(keyspace_name, std::move(ranges_mm));
}
set_mode(mode::LEAVING);
auto stream_success = stream_ranges(std::move(ranges_to_stream));
// wait for the transfer runnables to signal the latch.
slogger.debug("waiting for stream acks.");
try {
co_await std::move(stream_success);
} catch (...) {
slogger.warn("unbootstrap fails to stream : {}", std::current_exception());
throw;
}
slogger.debug("stream acks all received.");
}
}
future<> storage_service::removenode_add_ranges(lw_shared_ptr<dht::range_streamer> streamer, gms::inet_address leaving_node) {
auto my_address = get_broadcast_address();
auto ks_erms = _db.local().get_non_local_strategy_keyspaces_erms();
for (const auto& [keyspace_name, erm] : ks_erms) {
std::unordered_multimap<dht::token_range, inet_address> changed_ranges = co_await get_changed_ranges_for_leaving(erm, leaving_node);
dht::token_range_vector my_new_ranges;
for (auto& x : changed_ranges) {
if (x.second == my_address) {
my_new_ranges.emplace_back(x.first);
}
}
std::unordered_multimap<inet_address, dht::token_range> source_ranges = co_await get_new_source_ranges(erm, my_new_ranges);
std::unordered_map<inet_address, dht::token_range_vector> ranges_per_endpoint;
for (auto& x : source_ranges) {
ranges_per_endpoint[x.first].emplace_back(x.second);
}
streamer->add_rx_ranges(keyspace_name, std::move(ranges_per_endpoint));
}
}
future<> storage_service::removenode_with_stream(gms::inet_address leaving_node,
frozen_topology_guard topo_guard,
shared_ptr<abort_source> as_ptr) {
return seastar::async([this, leaving_node, as_ptr, topo_guard] {
auto tmptr = get_token_metadata_ptr();
abort_source as;
auto sub = _abort_source.subscribe([&as] () noexcept {
if (!as.abort_requested()) {
as.request_abort();
}
});
if (!as_ptr) {
throw std::runtime_error("removenode_with_stream: abort_source is nullptr");
}
auto as_ptr_sub = as_ptr->subscribe([&as] () noexcept {
if (!as.abort_requested()) {
as.request_abort();
}
});
auto streamer = make_lw_shared<dht::range_streamer>(_db, _stream_manager, tmptr, as, get_broadcast_address(), _snitch.local()->get_location(), "Removenode", streaming::stream_reason::removenode, topo_guard);
removenode_add_ranges(streamer, leaving_node).get();
try {
streamer->stream_async().get();
} catch (...) {
slogger.warn("removenode_with_stream: stream failed: {}", std::current_exception());
throw;
}
});
}
future<> storage_service::excise(std::unordered_set<token> tokens, inet_address endpoint, gms::permit_id pid) {
slogger.info("Removing tokens {} for {}", tokens, endpoint);
// FIXME: HintedHandOffManager.instance.deleteHintsForEndpoint(endpoint);
co_await remove_endpoint(endpoint, pid);
auto tmlock = std::make_optional(co_await get_token_metadata_lock());
auto tmptr = co_await get_mutable_token_metadata_ptr();
tmptr->remove_endpoint(endpoint);
tmptr->remove_bootstrap_tokens(tokens);
co_await update_topology_change_info(tmptr, ::format("excise {}", endpoint));
co_await replicate_to_all_cores(std::move(tmptr));
tmlock.reset();
co_await notify_left(endpoint);
}
future<> storage_service::excise(std::unordered_set<token> tokens, inet_address endpoint, int64_t expire_time, gms::permit_id pid) {
add_expire_time_if_found(endpoint, expire_time);
return excise(tokens, endpoint, pid);
}
future<> storage_service::leave_ring() {
co_await _cdc_gens.local().leave_ring();
co_await _sys_ks.local().set_bootstrap_state(db::system_keyspace::bootstrap_state::NEEDS_BOOTSTRAP);
co_await mutate_token_metadata([this] (mutable_token_metadata_ptr tmptr) {
auto endpoint = get_broadcast_address();
tmptr->remove_endpoint(endpoint);
return update_topology_change_info(std::move(tmptr), ::format("leave_ring {}", endpoint));
});
auto expire_time = _gossiper.compute_expire_time().time_since_epoch().count();
co_await _gossiper.add_local_application_state(gms::application_state::STATUS,
versioned_value::left(co_await _sys_ks.local().get_local_tokens(), expire_time));
auto delay = std::max(get_ring_delay(), gms::gossiper::INTERVAL);
slogger.info("Announcing that I have left the ring for {}ms", delay.count());
co_await sleep_abortable(delay, _abort_source);
}
future<>
storage_service::stream_ranges(std::unordered_map<sstring, std::unordered_multimap<dht::token_range, inet_address>> ranges_to_stream_by_keyspace) {
auto streamer = dht::range_streamer(_db, _stream_manager, get_token_metadata_ptr(), _abort_source,
get_broadcast_address(),
_snitch.local()->get_location(),
"Unbootstrap",
streaming::stream_reason::decommission,
null_topology_guard);
for (auto& entry : ranges_to_stream_by_keyspace) {
const auto& keyspace = entry.first;
auto& ranges_with_endpoints = entry.second;
if (ranges_with_endpoints.empty()) {
continue;
}
std::unordered_map<inet_address, dht::token_range_vector> ranges_per_endpoint;
for (auto& end_point_entry : ranges_with_endpoints) {
dht::token_range r = end_point_entry.first;
inet_address endpoint = end_point_entry.second;
ranges_per_endpoint[endpoint].emplace_back(r);
co_await coroutine::maybe_yield();
}
streamer.add_tx_ranges(keyspace, std::move(ranges_per_endpoint));
}
try {
co_await streamer.stream_async();
slogger.info("stream_ranges successful");
} catch (...) {
auto ep = std::current_exception();
slogger.warn("stream_ranges failed: {}", ep);
std::rethrow_exception(std::move(ep));
}
}
void storage_service::add_expire_time_if_found(inet_address endpoint, int64_t expire_time) {
if (expire_time != 0L) {
using clk = gms::gossiper::clk;
auto time = clk::time_point(clk::duration(expire_time));
_gossiper.add_expire_time_for_endpoint(endpoint, time);
}
}
future<> storage_service::shutdown_protocol_servers() {
for (auto& server : _protocol_servers) {
slogger.info("Shutting down {} server", server->name());
try {
co_await server->stop_server();
} catch (...) {
slogger.error("Unexpected error shutting down {} server: {}",
server->name(), std::current_exception());
throw;
}
slogger.info("Shutting down {} server was successful", server->name());
}
}
future<std::unordered_multimap<inet_address, dht::token_range>>
storage_service::get_new_source_ranges(locator::vnode_effective_replication_map_ptr erm, const dht::token_range_vector& ranges) const {
auto my_address = get_broadcast_address();
std::unordered_map<dht::token_range, inet_address_vector_replica_set> range_addresses = co_await erm->get_range_addresses();
std::unordered_multimap<inet_address, dht::token_range> source_ranges;
// find alive sources for our new ranges
auto tmptr = erm->get_token_metadata_ptr();
for (auto r : ranges) {
inet_address_vector_replica_set sources;
auto it = range_addresses.find(r);
if (it != range_addresses.end()) {
sources = it->second;
}
tmptr->get_topology().sort_by_proximity(my_address, sources);
if (std::find(sources.begin(), sources.end(), my_address) != sources.end()) {
auto err = ::format("get_new_source_ranges: sources={}, my_address={}", sources, my_address);
slogger.warn("{}", err);
throw std::runtime_error(err);
}
for (auto& source : sources) {
if (_gossiper.is_alive(source)) {
source_ranges.emplace(source, r);
break;
}
}
co_await coroutine::maybe_yield();
}
co_return source_ranges;
}
future<> storage_service::move(token new_token) {
return run_with_api_lock(sstring("move"), [] (storage_service& ss) mutable {
return make_exception_future<>(std::runtime_error("Move operation is not supported only more"));
});
}
future<std::vector<storage_service::token_range_endpoints>>
storage_service::describe_ring(const sstring& keyspace, bool include_only_local_dc) const {
return locator::describe_ring(_db.local(), _gossiper, keyspace, include_only_local_dc);
}
future<std::unordered_map<dht::token_range, inet_address_vector_replica_set>>
storage_service::construct_range_to_endpoint_map(
locator::vnode_effective_replication_map_ptr erm,
const dht::token_range_vector& ranges) const {
std::unordered_map<dht::token_range, inet_address_vector_replica_set> res;
res.reserve(ranges.size());
for (auto r : ranges) {
res[r] = erm->get_natural_endpoints(
r.end() ? r.end()->value() : dht::maximum_token());
co_await coroutine::maybe_yield();
}
co_return res;
}
std::map<token, inet_address> storage_service::get_token_to_endpoint_map() {
return get_token_metadata().get_normal_and_bootstrapping_token_to_endpoint_map();
}
std::chrono::milliseconds storage_service::get_ring_delay() {
auto ring_delay = _db.local().get_config().ring_delay_ms();
slogger.trace("Get RING_DELAY: {}ms", ring_delay);
return std::chrono::milliseconds(ring_delay);
}
future<locator::token_metadata_lock> storage_service::get_token_metadata_lock() noexcept {
assert(this_shard_id() == 0);
return _shared_token_metadata.get_lock();
}
// Acquire the token_metadata lock and get a mutable_token_metadata_ptr.
// Pass that ptr to \c func, and when successfully done,
// replicate it to all cores.
//
// By default the merge_lock (that is unified with the token_metadata_lock)
// is acquired for mutating the token_metadata. Pass acquire_merge_lock::no
// when called from paths that already acquire the merge_lock, like
// db::schema_tables::do_merge_schema.
//
// Note: must be called on shard 0.
future<> storage_service::mutate_token_metadata(std::function<future<> (mutable_token_metadata_ptr)> func, acquire_merge_lock acquire_merge_lock) noexcept {
assert(this_shard_id() == 0);
std::optional<token_metadata_lock> tmlock;
if (acquire_merge_lock) {
tmlock.emplace(co_await get_token_metadata_lock());
}
auto tmptr = co_await get_mutable_token_metadata_ptr();
co_await func(tmptr);
co_await replicate_to_all_cores(std::move(tmptr));
}
future<> storage_service::update_topology_change_info(mutable_token_metadata_ptr tmptr, sstring reason) {
assert(this_shard_id() == 0);
try {
locator::dc_rack_fn<gms::inet_address> get_dc_rack_from_gossiper([this] (inet_address ep) { return get_dc_rack_for(ep); });
co_await tmptr->update_topology_change_info(get_dc_rack_from_gossiper);
} catch (...) {
auto ep = std::current_exception();
slogger.error("Failed to update topology change info for {}: {}", reason, ep);
std::rethrow_exception(std::move(ep));
}
}
future<> storage_service::update_topology_change_info(sstring reason, acquire_merge_lock acquire_merge_lock) {
return mutate_token_metadata([this, reason = std::move(reason)] (mutable_token_metadata_ptr tmptr) mutable {
return update_topology_change_info(std::move(tmptr), std::move(reason));
}, acquire_merge_lock);
}
future<> storage_service::keyspace_changed(const sstring& ks_name) {
// The keyspace_changed notification is called on all shards
// after any keyspace schema change, but we need to mutate_token_metadata
// once after all shards are done with database::update_keyspace.
// mutate_token_metadata (via update_topology_change_info) will update the
// token metadata and effective_replication_map on all shards.
if (this_shard_id() != 0) {
return make_ready_future<>();
}
// Update pending ranges since keyspace can be changed after we calculate pending ranges.
sstring reason = ::format("keyspace {}", ks_name);
return update_topology_change_info(reason, acquire_merge_lock::no);
}
void storage_service::on_update_tablet_metadata() {
if (this_shard_id() != 0) {
// replicate_to_all_cores() takes care of other shards.
return;
}
// FIXME: Avoid reading whole tablet metadata on partial changes.
load_tablet_metadata().get();
_topology_state_machine.event.broadcast(); // wake up load balancer.
}
future<> storage_service::load_tablet_metadata() {
if (!_db.local().get_config().check_experimental(db::experimental_features_t::feature::TABLETS)) {
return make_ready_future<>();
}
return mutate_token_metadata([this] (mutable_token_metadata_ptr tmptr) -> future<> {
tmptr->set_tablets(co_await replica::read_tablet_metadata(_qp));
tmptr->tablets().set_balancing_enabled(_topology_state_machine._topology.tablet_balancing_enabled);
}, acquire_merge_lock::no);
}
future<> storage_service::snitch_reconfigured() {
assert(this_shard_id() == 0);
auto& snitch = _snitch.local();
co_await mutate_token_metadata([&] (mutable_token_metadata_ptr tmptr) -> future<> {
// re-read local rack and DC info
tmptr->update_topology(get_broadcast_address(), snitch->get_location());
return make_ready_future<>();
});
if (_gossiper.is_enabled()) {
co_await _gossiper.add_local_application_state(snitch->get_app_states());
}
}
future<raft_topology_cmd_result> storage_service::raft_topology_cmd_handler(raft::term_t term, uint64_t cmd_index, const raft_topology_cmd& cmd) {
raft_topology_cmd_result result;
slogger.trace("raft topology: topology cmd rpc {} is called", cmd.cmd);
// The retrier does:
// If no operation was previously started - start it now
// If previous operation still running - wait for it an return its result
// If previous operation completed successfully - return immediately
// If previous operation failed - restart it
auto retrier = [] (std::optional<shared_future<>>& f, auto&& func) -> future<> {
if (!f || f->failed()) {
if (f) {
slogger.info("raft topology: retry streaming after previous attempt failed with {}", f->get_future().get_exception());
} else {
slogger.info("raft topology: start streaming");
}
f = func();
} else {
slogger.debug("raft topology: already streaming");
}
co_await f.value().get_future();
slogger.info("raft topology: streaming completed");
};
try {
auto& raft_server = _group0->group0_server();
// do barrier to make sure we always see the latest topology
co_await raft_server.read_barrier(&_group0_as);
if (raft_server.get_current_term() != term) {
// Return an error since the command is from outdated leader
co_return result;
}
{
auto& state = _raft_topology_cmd_handler_state;
if (state.term != term) {
state.term = term;
} else if (cmd_index <= state.last_index) {
// Return an error since the command is outdated
co_return result;
}
state.last_index = cmd_index;
}
// We capture the topology version right after the checks
// above, before any yields. This is crucial since _topology_state_machine._topology
// might be altered concurrently while this method is running,
// which can cause the fence command to apply an invalid fence version.
const auto version = _topology_state_machine._topology.version;
switch (cmd.cmd) {
case raft_topology_cmd::command::barrier: {
// This barrier might have been issued by the topology coordinator
// as a step in enabling a feature, i.e. it noticed that all
// nodes support some feature, then issue the barrier to make
// sure that all nodes observed this fact in their local state
// (a node cannot revoke support for a feature after that), and
// after receiving a confirmation from all nodes it will mark
// the feature as enabled.
//
// However, it might happen that the node handles this request
// early in the boot process, before it did the second feature
// check that happens when the node updates its metadata
// in `system.topology`. The node might have committed a command
// that advertises support for a feature as the last node
// to do so, crashed and now it doesn't support it. This should
// be rare, but it can happen and we can detect it right here.
std::exception_ptr ex;
try {
const auto& enabled_features = _topology_state_machine._topology.enabled_features;
const auto unsafe_to_disable_features = _topology_state_machine._topology.calculate_not_yet_enabled_features();
_feature_service.check_features(enabled_features, unsafe_to_disable_features);
} catch (const gms::unsupported_feature_exception&) {
ex = std::current_exception();
}
if (ex) {
slogger.error("raft topology: feature check during barrier failed: {}", ex);
co_await drain();
break;
}
// we already did read barrier above
result.status = raft_topology_cmd_result::command_status::success;
}
break;
case raft_topology_cmd::command::barrier_and_drain: {
co_await container().invoke_on_all([version] (storage_service& ss) -> future<> {
const auto current_version = ss._shared_token_metadata.get()->get_version();
slogger.debug("Got raft_topology_cmd::barrier_and_drain, version {}, current version {}",
version, current_version);
// This shouldn't happen under normal operation, it's only plausible
// if the topology change coordinator has
// moved to another node and managed to update the topology
// parallel to this method. The previous coordinator
// should be inactive now, so it won't observe this
// exception. By returning exception we aim
// to reveal any other conditions where this may arise.
if (current_version != version) {
co_await coroutine::return_exception(std::runtime_error(
::format("raft topology: command::barrier_and_drain, the version has changed, "
"version {}, current_version {}, the topology change coordinator "
" had probably migrated to another node",
version, current_version)));
}
co_await ss._shared_token_metadata.stale_versions_in_use();
co_await get_topology_session_manager().drain_closing_sessions();
slogger.debug("raft_topology_cmd::barrier_and_drain done");
});
result.status = raft_topology_cmd_result::command_status::success;
}
break;
case raft_topology_cmd::command::stream_ranges: {
const auto& rs = _topology_state_machine._topology.find(raft_server.id())->second;
auto tstate = _topology_state_machine._topology.tstate;
if (!rs.ring ||
(tstate != topology::transition_state::write_both_read_old && rs.state != node_state::normal && rs.state != node_state::rebuilding)) {
slogger.warn("raft topology: got stream_ranges request while my tokens state is {} and node state is {}", tstate, rs.state);
break;
}
utils::get_local_injector().inject("stream_ranges_fail",
[] { throw std::runtime_error("stream_range failed due to error injection"); });
switch(rs.state) {
case node_state::bootstrapping:
case node_state::replacing: {
set_mode(mode::BOOTSTRAP);
// See issue #4001
co_await mark_existing_views_as_built();
co_await _db.invoke_on_all([] (replica::database& db) {
for (auto& cf : db.get_non_system_column_families()) {
cf->notify_bootstrap_or_replace_start();
}
});
if (rs.state == node_state::bootstrapping) {
if (!_topology_state_machine._topology.normal_nodes.empty()) { // stream only if there is a node in normal state
co_await retrier(_bootstrap_result, coroutine::lambda([&] () -> future<> {
if (is_repair_based_node_ops_enabled(streaming::stream_reason::bootstrap)) {
co_await _repair.local().bootstrap_with_repair(get_token_metadata_ptr(), rs.ring.value().tokens);
} else {
dht::boot_strapper bs(_db, _stream_manager, _abort_source, get_broadcast_address(),
locator::endpoint_dc_rack{rs.datacenter, rs.rack}, rs.ring.value().tokens, get_token_metadata_ptr());
co_await bs.bootstrap(streaming::stream_reason::bootstrap, _gossiper, _topology_state_machine._topology.session);
}
}));
}
// Bootstrap did not complete yet, but streaming did
} else {
co_await retrier(_bootstrap_result, coroutine::lambda([&] () ->future<> {
if (!_topology_state_machine._topology.req_param.contains(raft_server.id())) {
on_internal_error(slogger, ::format("Cannot find request_param for node id {}", raft_server.id()));
}
if (is_repair_based_node_ops_enabled(streaming::stream_reason::replace)) {
// FIXME: we should not need to translate ids to IPs here. See #6403.
std::unordered_set<gms::inet_address> ignored_ips;
for (const auto& id : std::get<replace_param>(_topology_state_machine._topology.req_param[raft_server.id()]).ignored_ids) {
auto ip = _group0->address_map().find(id);
if (!ip) {
on_fatal_internal_error(slogger, ::format("Cannot find a mapping from node id {} to its ip", id));
}
ignored_ips.insert(*ip);
}
co_await _repair.local().replace_with_repair(get_token_metadata_ptr(), rs.ring.value().tokens, std::move(ignored_ips));
} else {
dht::boot_strapper bs(_db, _stream_manager, _abort_source, get_broadcast_address(),
locator::endpoint_dc_rack{rs.datacenter, rs.rack}, rs.ring.value().tokens, get_token_metadata_ptr());
auto replaced_id = std::get<replace_param>(_topology_state_machine._topology.req_param[raft_server.id()]).replaced_id;
auto existing_ip = _group0->address_map().find(replaced_id);
assert(existing_ip);
co_await bs.bootstrap(streaming::stream_reason::replace, _gossiper, _topology_state_machine._topology.session, *existing_ip);
}
}));
}
co_await _db.invoke_on_all([] (replica::database& db) {
for (auto& cf : db.get_non_system_column_families()) {
cf->notify_bootstrap_or_replace_end();
}
});
result.status = raft_topology_cmd_result::command_status::success;
}
break;
case node_state::decommissioning:
co_await retrier(_decommission_result, coroutine::lambda([&] () { return unbootstrap(); }));
result.status = raft_topology_cmd_result::command_status::success;
break;
case node_state::normal: {
// If asked to stream a node in normal state it means that remove operation is running
// Find the node that is been removed
auto it = boost::find_if(_topology_state_machine._topology.transition_nodes, [] (auto& e) { return e.second.state == node_state::removing; });
if (it == _topology_state_machine._topology.transition_nodes.end()) {
slogger.warn("raft topology: got stream_ranges request while my state is normal but cannot find a node that is been removed");
break;
}
auto id = it->first;
slogger.debug("raft topology: streaming to remove node {}", id);
const auto& am = _group0->address_map();
auto ip = am.find(id); // map node id to ip
assert (ip); // what to do if address is unknown?
co_await retrier(_remove_result[id], coroutine::lambda([&] () {
auto as = make_shared<abort_source>();
auto sub = _abort_source.subscribe([as] () noexcept {
if (!as->abort_requested()) {
as->request_abort();
}
});
if (is_repair_based_node_ops_enabled(streaming::stream_reason::removenode)) {
if (!_topology_state_machine._topology.req_param.contains(id)) {
on_internal_error(slogger, ::format("Cannot find request_param for node id {}", id));
}
// FIXME: we should not need to translate ids to IPs here. See #6403.
std::list<gms::inet_address> ignored_ips;
for (const auto& ignored_id : std::get<removenode_param>(_topology_state_machine._topology.req_param[id]).ignored_ids) {
auto ip = _group0->address_map().find(ignored_id);
if (!ip) {
on_fatal_internal_error(slogger, ::format("Cannot find a mapping from node id {} to its ip", ignored_id));
}
ignored_ips.push_back(*ip);
}
auto ops = seastar::make_shared<node_ops_info>(node_ops_id::create_random_id(), as, std::move(ignored_ips));
return _repair.local().removenode_with_repair(get_token_metadata_ptr(), *ip, ops);
} else {
return removenode_with_stream(*ip, _topology_state_machine._topology.session, as);
}
}));
result.status = raft_topology_cmd_result::command_status::success;
}
break;
case node_state::rebuilding: {
auto source_dc = std::get<rebuild_param>(_topology_state_machine._topology.req_param[raft_server.id()]).source_dc;
slogger.info("raft topology: rebuild from dc: {}", source_dc == "" ? "(any dc)" : source_dc);
co_await retrier(_rebuild_result, [&] () -> future<> {
auto tmptr = get_token_metadata_ptr();
if (is_repair_based_node_ops_enabled(streaming::stream_reason::rebuild)) {
co_await _repair.local().rebuild_with_repair(tmptr, std::move(source_dc));
} else {
auto streamer = make_lw_shared<dht::range_streamer>(_db, _stream_manager, tmptr, _abort_source,
get_broadcast_address(), _snitch.local()->get_location(), "Rebuild", streaming::stream_reason::rebuild,
_topology_state_machine._topology.session);
streamer->add_source_filter(std::make_unique<dht::range_streamer::failure_detector_source_filter>(_gossiper.get_unreachable_members()));
if (source_dc != "") {
streamer->add_source_filter(std::make_unique<dht::range_streamer::single_datacenter_filter>(source_dc));
}
auto ks_erms = _db.local().get_non_local_strategy_keyspaces_erms();
for (const auto& [keyspace_name, erm] : ks_erms) {
co_await streamer->add_ranges(keyspace_name, erm, get_ranges_for_endpoint(erm, get_broadcast_address()), _gossiper, false);
}
try {
co_await streamer->stream_async();
slogger.info("raft topology: streaming for rebuild successful");
} catch (...) {
auto ep = std::current_exception();
// This is used exclusively through JMX, so log the full trace but only throw a simple RTE
slogger.warn("raft topology: error while rebuilding node: {}", ep);
std::rethrow_exception(std::move(ep));
}
}
});
_rebuild_result.reset();
result.status = raft_topology_cmd_result::command_status::success;
}
break;
case node_state::left_token_ring:
case node_state::left:
case node_state::none:
case node_state::removing:
case node_state::rollback_to_normal:
on_fatal_internal_error(slogger, ::format("Node {} got streaming request in state {}. It should be either dead or not part of the cluster",
raft_server.id(), rs.state));
break;
}
}
break;
case raft_topology_cmd::command::shutdown:
if (_shutdown_request_promise) {
std::exchange(_shutdown_request_promise, std::nullopt)->set_value();
} else {
slogger.warn("raft topology: got shutdown request while not decommissioning");
}
break;
}
} catch (...) {
slogger.error("raft topology: raft_topology_cmd failed with: {}", std::current_exception());
}
co_return result;
}
future<> storage_service::update_fence_version(token_metadata::version_t new_version) {
return container().invoke_on_all([new_version] (storage_service& ss) {
ss._shared_token_metadata.update_fence_version(new_version);
});
}
inet_address storage_service::host2ip(locator::host_id host) {
auto ip = _group0->address_map().find(raft::server_id(host.uuid()));
if (!ip) {
throw std::runtime_error(::format("Cannot map host {} to ip", host));
}
return *ip;
}
// Performs a replica-side operation for a given tablet.
// What operation is performed is determined by "op" based on the
// current state of tablet metadata. The coordinator is supposed to prepare tablet
// metadata according to his intent and trigger the operation,
// without passing any transient information.
//
// If the operation succeeds, and the coordinator is still valid, it means
// that the operation intended by the coordinator was performed.
// If the coordinator is no longer valid, the operation may succeed but
// the actual operation performed may be different than intended, it may
// be the one intended by the new coordinator. This is not a problem
// because the old coordinator should do nothing with such result.
//
// The triggers may be retried. They may also be reordered with older triggers, from
// the same or a different coordinator. There is a protocol which ensures that
// stale triggers won't cause operations to run beyond the migration stage they were
// intended for. For example, that streaming is not still running after the coordinator
// moved past the "streaming" stage, and that it won't be started when the stage is not appropriate.
// A non-stale trigger is the one which completed successfully and caused the valid coordinator
// to advance tablet migration to the next stage. Other triggers are called stale.
// We can divide stale triggers into categories:
// (1) Those which start after the tablet was moved to the next stage
// Those which start before the tablet was moved to the next stage,
// (2) ...but after the non-stale trigger finished
// (3) ...but before the non-stale trigger finished
//
// By "start" I mean the atomic block which inserts into _tablet_ops, and by "finish" I mean
// removal from _tablet_ops.
// So event ordering is local from the perspective of this replica, and is linear because
// this happens on the same shard.
//
// What prevents (1) from running is the fact that triggers check the state of tablet
// metadata, and will fail immediately if the stage is not appropriate. It can happen
// that the trigger is so stale that it will match with an appropriate stage of the next
// migration of the same tablet. This is not a problem because we fall into the same
// category as a stale trigger which was started in the new migration, so cases (2) or (3) apply.
//
// What prevents (2) from running is the fact that after the coordinator moves on to
// the next stage, it executes a token metadata barrier, which will wait for such triggers
// to complete as they hold on to erm via tablet_metadata_barrier. They should be aborted
// soon after the coordinator changes the stage by the means of tablet_metadata_barrier::get_abort_source().
//
// What prevents (3) from running is that they will join with the non-stale trigger, or non-stale
// trigger will join with them, depending on which came first. In that case they finish at the same time.
//
// It's very important that the global token metadata barrier involves all nodes which
// may receive stale triggers started in the previous stage, so that those nodes will
// see tablet metadata which reflects group0 state. This will cut-off stale triggers
// as soon as the coordinator moves to the next stage.
future<> storage_service::do_tablet_operation(locator::global_tablet_id tablet,
sstring op_name,
std::function<future<>(locator::tablet_metadata_guard&)> op) {
// The coordinator may not execute global token metadata barrier before triggering the operation, so we need
// a barrier here to see the token metadata which is at least as recent as that of the sender.
auto& raft_server = _group0->group0_server();
co_await raft_server.read_barrier(&_group0_as);
if (_tablet_ops.contains(tablet)) {
slogger.debug("{} retry joining with existing session for tablet {}", op_name, tablet);
co_await _tablet_ops[tablet].done.get_future();
co_return;
}
locator::tablet_metadata_guard guard(_db.local().find_column_family(tablet.table), tablet);
auto& as = guard.get_abort_source();
auto sub = _group0_as.subscribe([&as] () noexcept {
as.request_abort();
});
auto async_gate_holder = _async_gate.hold();
promise<> p;
_tablet_ops.emplace(tablet, tablet_operation {
op_name, seastar::shared_future<>(p.get_future())
});
auto erase_registry_entry = seastar::defer([&] {
_tablet_ops.erase(tablet);
});
try {
co_await op(guard);
p.set_value();
slogger.debug("{} for tablet migration of {} successful", op_name, tablet);
} catch (...) {
p.set_exception(std::current_exception());
slogger.warn("{} for tablet migration of {} failed: {}", op_name, tablet, std::current_exception());
throw;
}
}
// Streams data to the pending tablet replica of a given tablet on this node.
// The source tablet replica is determined from the current transition info of the tablet.
future<> storage_service::stream_tablet(locator::global_tablet_id tablet) {
return do_tablet_operation(tablet, "Streaming", [this, tablet] (locator::tablet_metadata_guard& guard) -> future<> {
auto tm = guard.get_token_metadata();
auto& tmap = guard.get_tablet_map();
auto* trinfo = tmap.get_tablet_transition_info(tablet.tablet);
// Check if the request is still valid.
// If there is mismatch, it means this streaming was canceled and the coordinator moved on.
if (!trinfo) {
throw std::runtime_error(format("No transition info for tablet {}", tablet));
}
if (trinfo->stage != locator::tablet_transition_stage::streaming) {
throw std::runtime_error(format("Tablet {} stage is not at streaming", tablet));
}
auto topo_guard = trinfo->session_id;
if (!trinfo->session_id) {
throw std::runtime_error(format("Tablet {} session is not set", tablet));
}
if (trinfo->pending_replica.host != tm->get_my_id()) {
throw std::runtime_error(format("Tablet {} has pending replica different than this one", tablet));
}
auto& tinfo = tmap.get_tablet_info(tablet.tablet);
auto range = tmap.get_token_range(tablet.tablet);
locator::tablet_replica leaving_replica = locator::get_leaving_replica(tinfo, *trinfo);
if (leaving_replica.host == tm->get_my_id()) {
// The algorithm doesn't work with tablet migration within the same node because
// it assumes there is only one tablet replica, picked by the sharder, on local node.
throw std::runtime_error(format("Cannot stream within the same node, tablet: {}, shard {} -> {}",
tablet, leaving_replica.shard, trinfo->pending_replica.shard));
}
auto leaving_replica_ip = host2ip(leaving_replica.host);
auto& table = _db.local().find_column_family(tablet.table);
std::vector<sstring> tables = {table.schema()->cf_name()};
auto streamer = make_lw_shared<dht::range_streamer>(_db, _stream_manager, std::move(tm), guard.get_abort_source(),
get_broadcast_address(), _snitch.local()->get_location(),
"Tablet migration", streaming::stream_reason::tablet_migration, topo_guard, std::move(tables));
tm = nullptr;
streamer->add_source_filter(std::make_unique<dht::range_streamer::failure_detector_source_filter>(
_gossiper.get_unreachable_members()));
std::unordered_map<inet_address, dht::token_range_vector> ranges_per_endpoint;
ranges_per_endpoint[leaving_replica_ip].emplace_back(range);
streamer->add_rx_ranges(table.schema()->ks_name(), std::move(ranges_per_endpoint));
co_await streamer->stream_async();
co_return;
});
}
future<> storage_service::cleanup_tablet(locator::global_tablet_id tablet) {
return do_tablet_operation(tablet, "Cleanup", [this, tablet] (locator::tablet_metadata_guard& guard) {
shard_id shard;
{
auto tm = guard.get_token_metadata();
auto& tmap = guard.get_tablet_map();
auto *trinfo = tmap.get_tablet_transition_info(tablet.tablet);
// Check if the request is still valid.
// If there is mismatch, it means this cleanup was canceled and the coordinator moved on.
if (!trinfo) {
throw std::runtime_error(format("No transition info for tablet {}", tablet));
}
if (trinfo->stage != locator::tablet_transition_stage::cleanup) {
throw std::runtime_error(format("Tablet {} stage is not at cleanup", tablet));
}
auto& tinfo = tmap.get_tablet_info(tablet.tablet);
locator::tablet_replica leaving_replica = locator::get_leaving_replica(tinfo, *trinfo);
if (leaving_replica.host != tm->get_my_id()) {
throw std::runtime_error(format("Tablet {} has leaving replica different than this one", tablet));
}
auto shard_opt = tmap.get_shard(tablet.tablet, tm->get_my_id());
if (!shard_opt) {
on_internal_error(slogger, format("Tablet {} has no shard on this node", tablet));
}
shard = *shard_opt;
}
return _db.invoke_on(shard, [tablet] (replica::database& db) {
auto& table = db.find_column_family(tablet.table);
return table.cleanup_tablet(tablet.tablet);
});
});
}
future<> storage_service::move_tablet(table_id table, dht::token token, locator::tablet_replica src, locator::tablet_replica dst) {
auto holder = _async_gate.hold();
if (this_shard_id() != 0) {
// group0 is only set on shard 0.
co_return co_await container().invoke_on(0, [&] (auto& ss) {
return ss.move_tablet(table, token, src, dst);
});
}
while (true) {
auto guard = co_await _group0->client().start_operation(&_abort_source);
while (_topology_state_machine._topology.is_busy()) {
slogger.debug("move_tablet(): topology state machine is busy");
release_guard(std::move(guard));
co_await _topology_state_machine.event.wait();
guard = co_await _group0->client().start_operation(&_abort_source);
}
std::vector<canonical_mutation> updates;
auto ks_name = _db.local().find_schema(table)->ks_name();
auto& tmap = get_token_metadata().tablets().get_tablet_map(table);
auto tid = tmap.get_tablet_id(token);
auto& tinfo = tmap.get_tablet_info(tid);
auto last_token = tmap.get_last_token(tid);
auto gid = locator::global_tablet_id{table, tid};
// FIXME: Validate replication strategy constraints.
if (!locator::contains(tinfo.replicas, src)) {
throw std::runtime_error(format("Tablet {} has no replica on {}", gid, src));
}
auto* node = get_token_metadata().get_topology().find_node(dst.host);
if (!node) {
throw std::runtime_error(format("Unknown host: {}", dst.host));
}
if (dst.shard >= node->get_shard_count()) {
throw std::runtime_error(format("Host {} does not have shard {}", dst.shard));
}
if (src.host == dst.host) {
throw std::runtime_error("Migrating within the same node is not supported");
}
if (src == dst) {
co_return;
}
updates.push_back(canonical_mutation(replica::tablet_mutation_builder(guard.write_timestamp(), ks_name, table)
.set_new_replicas(last_token, locator::replace_replica(tinfo.replicas, src, dst))
.set_stage(last_token, locator::tablet_transition_stage::allow_write_both_read_old)
.build()));
updates.push_back(canonical_mutation(topology_mutation_builder(guard.write_timestamp())
.set_transition_state(topology::transition_state::tablet_migration)
.set_version(_topology_state_machine._topology.version + 1)
.build()));
sstring reason = format("Moving tablet {} from {} to {}", gid, src, dst);
slogger.info("raft topology: {}", reason);
slogger.trace("raft topology: do update {} reason {}", updates, reason);
topology_change change{std::move(updates)};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard, reason);
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard));
break;
} catch (group0_concurrent_modification&) {
slogger.debug("move_tablet(): concurrent modification, retrying");
}
}
// Wait for migration to finish.
co_await _topology_state_machine.event.wait([&] {
auto& tmap = get_token_metadata().tablets().get_tablet_map(table);
return !tmap.get_tablet_transition_info(tmap.get_tablet_id(token));
});
}
future<> storage_service::set_tablet_balancing_enabled(bool enabled) {
auto holder = _async_gate.hold();
if (this_shard_id() != 0) {
// group0 is only set on shard 0.
co_return co_await container().invoke_on(0, [&] (auto& ss) {
return ss.set_tablet_balancing_enabled(enabled);
});
}
while (true) {
group0_guard guard = co_await _group0->client().start_operation(&_abort_source);
while (_topology_state_machine._topology.is_busy()) {
slogger.debug("set_tablet_balancing_enabled(): topology is busy");
release_guard(std::move(guard));
co_await _topology_state_machine.event.wait();
guard = co_await _group0->client().start_operation(&_abort_source);
}
std::vector<canonical_mutation> updates;
updates.push_back(canonical_mutation(topology_mutation_builder(guard.write_timestamp())
.set_tablet_balancing_enabled(enabled)
.build()));
sstring reason = format("Setting tablet balancing to {}", enabled);
slogger.info("raft topology: {}", reason);
topology_change change{std::move(updates)};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard, reason);
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard));
break;
} catch (group0_concurrent_modification&) {
slogger.debug("set_tablet_balancing_enabled(): concurrent modification");
}
}
}
future<join_node_request_result> storage_service::join_node_request_handler(join_node_request_params params) {
join_node_request_result result;
slogger.info("raft topology: received request to join from host_id: {}", params.host_id);
if (params.cluster_name != _db.local().get_config().cluster_name()) {
result.result = join_node_request_result::rejected{
.reason = ::format("Cluster name check failed. This node cannot join the cluster "
"because it expected cluster name \"{}\" and not \"{}\"",
params.cluster_name,
_db.local().get_config().cluster_name()),
};
co_return result;
}
if (params.snitch_name != _db.local().get_snitch_name()) {
result.result = join_node_request_result::rejected{
.reason = ::format("Snitch name check failed. This node cannot join the cluster "
"because it uses \"{}\" and not \"{}\"",
params.snitch_name,
_db.local().get_snitch_name()),
};
co_return result;
}
co_await _topology_state_machine.event.when([this] {
// The first node defines the cluster and inserts its entry to the
// `system.topology` without checking anything. It is possible that the
// `join_node_request_handler` fires before the first node sets itself
// as a normal node, therefore we might need to wait until that happens,
// here. If we didn't do it, the topology coordinator could handle the
// joining node as the first one and skip the necessary join node
// handshake.
return !_topology_state_machine._topology.normal_nodes.empty();
});
auto& g0_server = _group0->group0_server();
if (params.replaced_id && *params.replaced_id == g0_server.current_leader()) {
// There is a peculiar case that can happen if the leader is killed
// and then replaced very quickly:
//
// - Cluster with nodes `A`, `B`, `C` - `A` is the topology
// coordinator/group0 leader,
// - `A` is killed,
// - New node `D` attempts to replace `A` with the same IP as `A`,
// sends `join_node_request` rpc to node `B`,
// - Node `B` handles the RPC and wants to perform group0 operation
// and wants to perform a barrier - still thinks that `A`
// is the leader and is alive, sends an RPC to its IP,
// - `D` accidentally receives the request that was meant to `A`
// but throws an exception because of host_id mismatch,
// - Failure is propagated back to `B`, and then to `D` - and `D`
// fails the replace operation.
//
// We can try to detect if this failure might happen: if the new node
// is going to replace but the ID of the replaced node is the same
// as the leader, wait for a short while until a reelection happens.
// If replaced ID == leader ID, then this indicates either the situation
// above or an operator error (actually trying to replace a live node).
const auto timeout = std::chrono::seconds(10);
slogger.warn("raft topology: the node {} which was requested to be"
" replaced has the same ID as the current group 0 leader ({});"
" this looks like an attempt to join a node with the same IP"
" as a leader which might have just crashed; waiting for"
" a reelection",
params.host_id, g0_server.current_leader());
abort_source as;
timer<lowres_clock> t;
t.set_callback([&as] {
as.request_abort();
});
t.arm(timeout);
try {
while (!g0_server.current_leader() || *params.replaced_id == g0_server.current_leader()) {
// FIXME: Wait for the next term instead of sleeping in a loop
// Waiting for state change is not enough because a new leader
// might be chosen without us going through the candidate state.
co_await sleep_abortable(std::chrono::milliseconds(100), as);
}
} catch (abort_requested_exception&) {
slogger.warn("raft topology: the node {} tries to replace the"
" current leader {} but the leader didn't change within"
" {}s. Rejecting the node",
params.host_id,
*params.replaced_id,
std::chrono::duration_cast<std::chrono::seconds>(timeout).count());
result.result = join_node_request_result::rejected{
.reason = format(
"It is only allowed to replace dead nodes, however the"
" node that was requested to be replaced is still seen"
" as the group0 leader after {}s, which indicates that"
" it might be still alive. You are either trying to replace"
" a live node or trying to replace a node very quickly"
" after it went down and reelection didn't happen within"
" the timeout. Refusing to continue",
std::chrono::duration_cast<std::chrono::seconds>(timeout).count()),
};
co_return result;
}
}
while (true) {
auto guard = co_await _group0->client().start_operation(&_group0_as);
if (const auto *p = _topology_state_machine._topology.find(params.host_id)) {
const auto& rs = p->second;
if (rs.state == node_state::left) {
slogger.warn("raft topology: the node {} attempted to join",
" but it was removed from the cluster. Rejecting"
" the node",
params.host_id);
result.result = join_node_request_result::rejected{
.reason = "The node has already been removed from the cluster",
};
} else {
slogger.warn("raft topology: the node {} attempted to join",
" again after an unfinished attempt but it is no longer"
" allowed to do so. Rejecting the node",
params.host_id);
result.result = join_node_request_result::rejected{
.reason = "The node requested to join before but didn't finish the procedure. "
"Please clear the data directory and restart.",
};
}
co_return result;
}
auto mutation = build_mutation_from_join_params(params, guard);
topology_change change{{std::move(mutation)}};
group0_command g0_cmd = _group0->client().prepare_command(std::move(change), guard,
format("raft topology: placing join request for {}", params.host_id));
try {
co_await _group0->client().add_entry(std::move(g0_cmd), std::move(guard), &_group0_as);
break;
} catch (group0_concurrent_modification&) {
slogger.info("raft topology: join_node_request: concurrent operation is detected, retrying.");
}
}
slogger.info("raft topology: placed join request for {}", params.host_id);
// Success
result.result = join_node_request_result::ok {};
co_return result;
}
future<join_node_response_result> storage_service::join_node_response_handler(join_node_response_params params) {
assert(this_shard_id() == 0);
// Usually this handler will only run once, but there are some cases where we might get more than one RPC,
// possibly happening at the same time, e.g.:
//
// - Another node becomes the topology coordinator while the old one waits for the RPC,
// - Topology coordinator finished the RPC but failed to update the group 0 state.
// Serialize handling the responses.
auto lock = co_await get_units(_join_node_response_handler_mutex, 1);
// Wait until we sent and completed the join_node_request RPC
co_await _join_node_request_done.get_shared_future(_group0_as);
if (_join_node_response_done.available()) {
// We already handled this RPC. No need to retry it. Return immediately for idempotence.
slogger.info("raft topology: the node got join_node_response RPC for the second time, ignoring");
co_return join_node_response_result{};
}
co_return co_await std::visit(overloaded_functor {
[&] (const join_node_response_params::accepted& acc) -> future<join_node_response_result> {
// Allow other nodes to mark the replacing node as alive. It has
// effect only if the replacing node is reusing the IP of the
// replaced node. In such a case, we do not allow the replacing
// node to advertise itself earlier. Thanks to this, if the
// topology sees the node being replaced as alive, it can safely
// reject the join request because it can be sure that it is not
// the replacing node that is alive.
co_await _gossiper.advertise_to_nodes({});
// Do a read barrier to read/initialize the topology state
auto& raft_server = _group0->group0_server();
co_await raft_server.read_barrier(&_group0_as);
// Calculate nodes to ignore
// TODO: ignore_dead_nodes setting for bootstrap
std::unordered_set<raft::server_id> ignored_ids;
auto my_request_it =
_topology_state_machine._topology.req_param.find(_group0->load_my_id());
if (my_request_it != _topology_state_machine._topology.req_param.end()) {
if (auto* replace = std::get_if<service::replace_param>(&my_request_it->second)) {
ignored_ids = replace->ignored_ids;
ignored_ids.insert(replace->replaced_id);
}
}
// After this RPC finishes, repair or streaming will be run, and
// both of them require this node to see the normal nodes as UP.
// This condition might not be true yet as this information is
// propagated through gossip. In order to reduce the chance of
// repair/streaming failure, wait here until we see normal nodes
// as UP (or the timeout elapses).
const auto& amap = _group0->address_map();
std::vector<gms::inet_address> sync_nodes;
// FIXME: https://github.com/scylladb/scylladb/issues/12279
// Keep trying to translate host IDs to IPs until all are available in gossip
// Ultimately, we should take this information from token_metadata
const auto sync_nodes_resolve_deadline = lowres_clock::now() + wait_for_live_nodes_timeout;
while (true) {
sync_nodes.clear();
std::vector<raft::server_id> untranslated_ids;
for (const auto& [id, _] : _topology_state_machine._topology.normal_nodes) {
if (ignored_ids.contains(id)) {
continue;
}
if (auto ip = amap.find(id)) {
sync_nodes.push_back(*ip);
} else {
untranslated_ids.push_back(id);
}
}
if (!untranslated_ids.empty()) {
if (lowres_clock::now() > sync_nodes_resolve_deadline) {
throw std::runtime_error(format(
"Failed to obtain IP addresses of nodes that should be seen"
" as alive within {}s",
std::chrono::duration_cast<std::chrono::seconds>(wait_for_live_nodes_timeout).count()));
}
static logger::rate_limit rate_limit{std::chrono::seconds(1)};
slogger.log(log_level::warn, rate_limit, "raft topology: cannot map nodes {} to ips, retrying.",
untranslated_ids);
co_await sleep_abortable(std::chrono::milliseconds(5), _group0_as);
} else {
break;
}
}
slogger.info("raft topology: coordinator accepted request to join, "
"waiting for nodes {} to be alive before responding and continuing",
sync_nodes);
co_await _gossiper.wait_alive(sync_nodes, wait_for_live_nodes_timeout);
slogger.info("raft topology: nodes {} are alive", sync_nodes);
// Unblock waiting join_node_rpc_handshaker::post_server_start,
// which will start the raft server and continue
_join_node_response_done.set_value();
co_return join_node_response_result{};
},
[&] (const join_node_response_params::rejected& rej) -> future<join_node_response_result> {
auto eptr = std::make_exception_ptr(std::runtime_error(
format("the topology coordinator rejected request to join the cluster: {}", rej.reason)));
_join_node_response_done.set_exception(std::move(eptr));
co_return join_node_response_result{};
},
}, params.response);
}
void storage_service::init_messaging_service(bool raft_topology_change_enabled) {
_messaging.local().register_node_ops_cmd([this] (const rpc::client_info& cinfo, node_ops_cmd_request req) {
auto coordinator = cinfo.retrieve_auxiliary<gms::inet_address>("baddr");
return container().invoke_on(0, [coordinator, req = std::move(req)] (auto& ss) mutable {
return ss.node_ops_cmd_handler(coordinator, std::move(req));
});
});
if (raft_topology_change_enabled) {
auto handle_raft_rpc = [this] (raft::server_id dst_id, auto handler) {
return container().invoke_on(0, [dst_id, handler = std::move(handler)] (auto& ss) mutable {
if (!ss._group0 || !ss._group0->joined_group0()) {
throw std::runtime_error("The node did not join group 0 yet");
}
if (ss._group0->load_my_id() != dst_id) {
throw raft_destination_id_not_correct(ss._group0->load_my_id(), dst_id);
}
return handler(ss);
});
};
ser::storage_service_rpc_verbs::register_raft_topology_cmd(&_messaging.local(), [handle_raft_rpc] (raft::server_id dst_id, raft::term_t term, uint64_t cmd_index, raft_topology_cmd cmd) {
return handle_raft_rpc(dst_id, [cmd = std::move(cmd), term, cmd_index] (auto& ss) {
return ss.raft_topology_cmd_handler(term, cmd_index, cmd);
});
});
ser::storage_service_rpc_verbs::register_raft_pull_topology_snapshot(&_messaging.local(), [handle_raft_rpc] (raft::server_id dst_id, raft_topology_pull_params params) {
return handle_raft_rpc(dst_id, [] (storage_service& ss) -> future<raft_topology_snapshot> {
std::vector<canonical_mutation> topology_mutations;
{
// FIXME: make it an rwlock, here we only need to lock for reads,
// might be useful if multiple nodes are trying to pull concurrently.
auto read_apply_mutex_holder = co_await ss._group0->client().hold_read_apply_mutex();
auto rs = co_await db::system_keyspace::query_mutations(
ss._db, db::system_keyspace::NAME, db::system_keyspace::TOPOLOGY);
auto s = ss._db.local().find_schema(db::system_keyspace::NAME, db::system_keyspace::TOPOLOGY);
topology_mutations.reserve(rs->partitions().size());
boost::range::transform(
rs->partitions(), std::back_inserter(topology_mutations), [s] (const partition& p) {
return canonical_mutation{p.mut().unfreeze(s)};
});
}
std::vector<canonical_mutation> cdc_generation_mutations;
{
// FIXME: when we bootstrap nodes in quick succession, the timestamp of the newest CDC generation
// may be for some time larger than the clocks of our nodes. The last bootstrapped node will only
// read the newest CDC generation into memory and not earlier ones, so it will only be able
// to coordinate writes to CDC-enabled tables after its clock advances to reach the newest
// generation's timestamp. In other words, it may not be able to coordinate writes for some
// time after bootstrapping and drivers connecting to it will receive errors.
// To fix that, we could store in topology a small history of recent CDC generation IDs
// (garbage-collected with time) instead of just the last one, and load all of them.
// Alternatively, a node would wait for some time before switching to normal state.
auto read_apply_mutex_holder = co_await ss._group0->client().hold_read_apply_mutex();
auto rs = co_await db::system_keyspace::query_mutations(
ss._db, db::system_keyspace::NAME, db::system_keyspace::CDC_GENERATIONS_V3);
auto s = ss._db.local().find_schema(db::system_keyspace::NAME, db::system_keyspace::CDC_GENERATIONS_V3);
cdc_generation_mutations.reserve(rs->partitions().size());
boost::range::transform(
rs->partitions(), std::back_inserter(cdc_generation_mutations), [s] (const partition& p) {
return canonical_mutation{p.mut().unfreeze(s)};
});
}
co_return raft_topology_snapshot{
.topology_mutations = std::move(topology_mutations),
.cdc_generation_mutations = std::move(cdc_generation_mutations),
};
});
});
ser::storage_service_rpc_verbs::register_tablet_stream_data(&_messaging.local(), [handle_raft_rpc] (raft::server_id dst_id, locator::global_tablet_id tablet) {
return handle_raft_rpc(dst_id, [tablet] (auto& ss) {
return ss.stream_tablet(tablet);
});
});
ser::storage_service_rpc_verbs::register_tablet_cleanup(&_messaging.local(), [handle_raft_rpc] (raft::server_id dst_id, locator::global_tablet_id tablet) {
return handle_raft_rpc(dst_id, [tablet] (auto& ss) {
return ss.cleanup_tablet(tablet);
});
});
ser::join_node_rpc_verbs::register_join_node_request(&_messaging.local(), [handle_raft_rpc] (raft::server_id dst_id, service::join_node_request_params params) {
return handle_raft_rpc(dst_id, [params = std::move(params)] (auto& ss) mutable {
return ss.join_node_request_handler(std::move(params));
});
});
ser::join_node_rpc_verbs::register_join_node_response(&_messaging.local(), [this] (raft::server_id dst_id, service::join_node_response_params params) {
return container().invoke_on(0, [dst_id, params = std::move(params)] (auto& ss) mutable -> future<join_node_response_result> {
co_await ss._join_node_group0_started.get_shared_future(ss._group0_as);
if (ss._group0->load_my_id() != dst_id) {
throw raft_destination_id_not_correct(ss._group0->load_my_id(), dst_id);
}
co_return co_await ss.join_node_response_handler(std::move(params));
});
});
}
}
future<> storage_service::uninit_messaging_service() {
return when_all_succeed(
_messaging.local().unregister_node_ops_cmd(),
ser::storage_service_rpc_verbs::unregister(&_messaging.local()),
ser::join_node_rpc_verbs::unregister(&_messaging.local())
).discard_result();
}
void storage_service::do_isolate_on_error(disk_error type)
{
static std::atomic<bool> isolated = { false };
if (!isolated.exchange(true)) {
slogger.error("Shutting down communications due to I/O errors until operator intervention: {} error: {}", type == disk_error::commit ? "Commitlog" : "Disk", std::current_exception());
// isolated protect us against multiple stops
//FIXME: discarded future.
(void)isolate();
}
}
future<> storage_service::isolate() {
return run_with_no_api_lock([] (storage_service& ss) {
return ss.stop_transport();
});
}
future<sstring> storage_service::get_removal_status() {
return run_with_no_api_lock([] (storage_service& ss) {
return make_ready_future<sstring>(sstring("No token removals in process."));
});
}
future<> storage_service::force_remove_completion() {
return run_with_no_api_lock([] (storage_service& ss) -> future<> {
while (!ss._operation_in_progress.empty()) {
if (ss._operation_in_progress != sstring("removenode")) {
throw std::runtime_error(::format("Operation {} is in progress, try again", ss._operation_in_progress));
}
// This flag will make removenode stop waiting for the confirmation,
// wait it to complete
slogger.info("Operation removenode is in progress, wait for it to complete");
co_await sleep_abortable(std::chrono::seconds(1), ss._abort_source);
}
ss._operation_in_progress = sstring("removenode_force");
try {
const auto& tm = ss.get_token_metadata();
if (!tm.get_leaving_endpoints().empty()) {
auto leaving = tm.get_leaving_endpoints();
slogger.warn("Removal not confirmed, Leaving={}", leaving);
for (auto endpoint : leaving) {
const auto host_id = tm.get_host_id_if_known(endpoint);
if (!host_id) {
slogger.warn("No host_id is found for endpoint {}", endpoint);
continue;
}
auto tokens = tm.get_tokens(endpoint);
auto permit = co_await ss._gossiper.lock_endpoint(endpoint, gms::null_permit_id);
const auto& pid = permit.id();
co_await ss._gossiper.advertise_token_removed(endpoint, *host_id, pid);
std::unordered_set<token> tokens_set(tokens.begin(), tokens.end());
co_await ss.excise(tokens_set, endpoint, pid);
slogger.info("force_remove_completion: removing endpoint {} from group 0", endpoint);
assert(ss._group0);
bool raft_available = co_await ss._group0->wait_for_raft();
if (raft_available) {
co_await ss._group0->remove_from_group0(raft::server_id{host_id->uuid()});
}
}
} else {
slogger.warn("No tokens to force removal on, call 'removenode' first");
}
ss._operation_in_progress = {};
} catch (...) {
ss._operation_in_progress = {};
throw;
}
});
}
/**
* Takes an ordered list of adjacent tokens and divides them in the specified number of ranges.
*/
static std::vector<std::pair<dht::token_range, uint64_t>>
calculate_splits(std::vector<dht::token> tokens, uint64_t split_count, replica::column_family& cf) {
auto sstables = cf.get_sstables();
const double step = static_cast<double>(tokens.size() - 1) / split_count;
auto prev_token_idx = 0;
std::vector<std::pair<dht::token_range, uint64_t>> splits;
splits.reserve(split_count);
for (uint64_t i = 1; i <= split_count; ++i) {
auto index = static_cast<uint32_t>(std::round(i * step));
dht::token_range range({{ std::move(tokens[prev_token_idx]), false }}, {{ tokens[index], true }});
// always return an estimate > 0 (see CASSANDRA-7322)
uint64_t estimated_keys_for_range = 0;
for (auto&& sst : *sstables) {
estimated_keys_for_range += sst->estimated_keys_for_range(range);
}
splits.emplace_back(std::move(range), std::max(static_cast<uint64_t>(cf.schema()->min_index_interval()), estimated_keys_for_range));
prev_token_idx = index;
}
return splits;
};
std::vector<std::pair<dht::token_range, uint64_t>>
storage_service::get_splits(const sstring& ks_name, const sstring& cf_name, range<dht::token> range, uint32_t keys_per_split) {
using range_type = dht::token_range;
auto& cf = _db.local().find_column_family(ks_name, cf_name);
auto schema = cf.schema();
auto sstables = cf.get_sstables();
uint64_t total_row_count_estimate = 0;
std::vector<dht::token> tokens;
std::vector<range_type> unwrapped;
if (range.is_wrap_around(dht::token_comparator())) {
auto uwr = range.unwrap();
unwrapped.emplace_back(std::move(uwr.second));
unwrapped.emplace_back(std::move(uwr.first));
} else {
unwrapped.emplace_back(std::move(range));
}
tokens.push_back(std::move(unwrapped[0].start().value_or(range_type::bound(dht::minimum_token()))).value());
for (auto&& r : unwrapped) {
std::vector<dht::token> range_tokens;
for (auto &&sst : *sstables) {
total_row_count_estimate += sst->estimated_keys_for_range(r);
auto keys = sst->get_key_samples(*cf.schema(), r);
std::transform(keys.begin(), keys.end(), std::back_inserter(range_tokens), [](auto&& k) { return std::move(k.token()); });
}
std::sort(range_tokens.begin(), range_tokens.end());
std::move(range_tokens.begin(), range_tokens.end(), std::back_inserter(tokens));
}
tokens.push_back(std::move(unwrapped[unwrapped.size() - 1].end().value_or(range_type::bound(dht::maximum_token()))).value());
// split_count should be much smaller than number of key samples, to avoid huge sampling error
constexpr uint32_t min_samples_per_split = 4;
uint64_t max_split_count = tokens.size() / min_samples_per_split + 1;
uint64_t split_count = std::max(uint64_t(1), std::min(max_split_count, total_row_count_estimate / keys_per_split));
return calculate_splits(std::move(tokens), split_count, cf);
};
dht::token_range_vector
storage_service::get_ranges_for_endpoint(const locator::vnode_effective_replication_map_ptr& erm, const gms::inet_address& ep) const {
return erm->get_ranges(ep);
}
// Caller is responsible to hold token_metadata valid until the returned future is resolved
future<dht::token_range_vector>
storage_service::get_all_ranges(const std::vector<token>& sorted_tokens) const {
if (sorted_tokens.empty())
co_return dht::token_range_vector();
int size = sorted_tokens.size();
dht::token_range_vector ranges;
ranges.reserve(size + 1);
ranges.push_back(dht::token_range::make_ending_with(range_bound<token>(sorted_tokens[0], true)));
co_await coroutine::maybe_yield();
for (int i = 1; i < size; ++i) {
dht::token_range r(range<token>::bound(sorted_tokens[i - 1], false), range<token>::bound(sorted_tokens[i], true));
ranges.push_back(r);
co_await coroutine::maybe_yield();
}
ranges.push_back(dht::token_range::make_starting_with(range_bound<token>(sorted_tokens[size-1], false)));
co_return ranges;
}
inet_address_vector_replica_set
storage_service::get_natural_endpoints(const sstring& keyspace,
const sstring& cf, const sstring& key) const {
auto schema = _db.local().find_schema(keyspace, cf);
partition_key pk = partition_key::from_nodetool_style_string(schema, key);
dht::token token = schema->get_partitioner().get_token(*schema, pk.view());
return get_natural_endpoints(keyspace, token);
}
inet_address_vector_replica_set
storage_service::get_natural_endpoints(const sstring& keyspace, const token& pos) const {
return _db.local().find_keyspace(keyspace).get_effective_replication_map()->get_natural_endpoints(pos);
}
future<> endpoint_lifecycle_notifier::notify_down(gms::inet_address endpoint) {
return seastar::async([this, endpoint] {
_subscribers.thread_for_each([endpoint] (endpoint_lifecycle_subscriber* subscriber) {
try {
subscriber->on_down(endpoint);
} catch (...) {
slogger.warn("Down notification failed {}: {}", endpoint, std::current_exception());
}
});
});
}
future<> storage_service::notify_down(inet_address endpoint) {
co_await container().invoke_on_all([endpoint] (auto&& ss) {
ss._messaging.local().remove_rpc_client(netw::msg_addr{endpoint, 0});
return ss._lifecycle_notifier.notify_down(endpoint);
});
slogger.debug("Notify node {} has been down", endpoint);
}
future<> endpoint_lifecycle_notifier::notify_left(gms::inet_address endpoint) {
return seastar::async([this, endpoint] {
_subscribers.thread_for_each([endpoint] (endpoint_lifecycle_subscriber* subscriber) {
try {
subscriber->on_leave_cluster(endpoint);
} catch (...) {
slogger.warn("Leave cluster notification failed {}: {}", endpoint, std::current_exception());
}
});
});
}
future<> storage_service::notify_left(inet_address endpoint) {
co_await container().invoke_on_all([endpoint] (auto&& ss) {
return ss._lifecycle_notifier.notify_left(endpoint);
});
slogger.debug("Notify node {} has left the cluster", endpoint);
}
future<> endpoint_lifecycle_notifier::notify_up(gms::inet_address endpoint) {
return seastar::async([this, endpoint] {
_subscribers.thread_for_each([endpoint] (endpoint_lifecycle_subscriber* subscriber) {
try {
subscriber->on_up(endpoint);
} catch (...) {
slogger.warn("Up notification failed {}: {}", endpoint, std::current_exception());
}
});
});
}
future<> storage_service::notify_up(inet_address endpoint) {
if (!_gossiper.is_cql_ready(endpoint) || !_gossiper.is_alive(endpoint)) {
co_return;
}
co_await container().invoke_on_all([endpoint] (auto&& ss) {
return ss._lifecycle_notifier.notify_up(endpoint);
});
slogger.debug("Notify node {} has been up", endpoint);
}
future<> endpoint_lifecycle_notifier::notify_joined(gms::inet_address endpoint) {
return seastar::async([this, endpoint] {
_subscribers.thread_for_each([endpoint] (endpoint_lifecycle_subscriber* subscriber) {
try {
subscriber->on_join_cluster(endpoint);
} catch (...) {
slogger.warn("Join cluster notification failed {}: {}", endpoint, std::current_exception());
}
});
});
}
future<> storage_service::notify_joined(inet_address endpoint) {
if (!_gossiper.is_normal(endpoint)) {
co_return;
}
co_await utils::get_local_injector().inject(
"storage_service_notify_joined_sleep", std::chrono::milliseconds{500});
co_await container().invoke_on_all([endpoint] (auto&& ss) {
ss._messaging.local().remove_rpc_client_with_ignored_topology(netw::msg_addr{endpoint, 0});
return ss._lifecycle_notifier.notify_joined(endpoint);
});
slogger.debug("Notify node {} has joined the cluster", endpoint);
}
future<> storage_service::notify_cql_change(inet_address endpoint, bool ready) {
if (ready) {
co_await notify_up(endpoint);
} else {
co_await notify_down(endpoint);
}
}
bool storage_service::is_normal_state_handled_on_boot(gms::inet_address node) {
return _normal_state_handled_on_boot.contains(node);
}
// Wait for normal state handlers to finish on boot
future<> storage_service::wait_for_normal_state_handled_on_boot() {
static logger::rate_limit rate_limit{std::chrono::seconds{5}};
static auto fmt_nodes_with_statuses = [this] (const auto& eps) {
return boost::algorithm::join(
eps | boost::adaptors::transformed([this] (const auto& ep) {
return ::format("({}, status={})", ep, _gossiper.get_gossip_status(ep));
}), ", ");
};
slogger.info("Started waiting for normal state handlers to finish");
auto start_time = std::chrono::steady_clock::now();
std::vector<gms::inet_address> eps;
while (true) {
eps = _gossiper.get_endpoints();
auto it = std::partition(eps.begin(), eps.end(),
[this, me = get_broadcast_address()] (const gms::inet_address& ep) {
return ep == me || !_gossiper.is_normal_ring_member(ep) || is_normal_state_handled_on_boot(ep);
});
if (it == eps.end()) {
break;
}
if (std::chrono::steady_clock::now() > start_time + std::chrono::seconds(60)) {
auto err = ::format("Timed out waiting for normal state handlers to finish for nodes {}",
fmt_nodes_with_statuses(boost::make_iterator_range(it, eps.end())));
slogger.error("{}", err);
throw std::runtime_error{std::move(err)};
}
slogger.log(log_level::info, rate_limit, "Normal state handlers not yet finished for nodes {}",
fmt_nodes_with_statuses(boost::make_iterator_range(it, eps.end())));
co_await sleep_abortable(std::chrono::milliseconds{100}, _abort_source);
}
slogger.info("Finished waiting for normal state handlers; endpoints observed in gossip: {}",
fmt_nodes_with_statuses(eps));
}
future<bool> storage_service::is_cleanup_allowed(sstring keyspace) {
return container().invoke_on(0, [keyspace = std::move(keyspace)] (storage_service& ss) {
auto my_address = ss.get_broadcast_address();
auto pending_ranges = ss._db.local().find_keyspace(keyspace).get_effective_replication_map()->has_pending_ranges(my_address);
bool is_bootstrap_mode = ss._operation_mode == mode::BOOTSTRAP;
slogger.debug("is_cleanup_allowed: keyspace={}, is_bootstrap_mode={}, pending_ranges={}",
keyspace, is_bootstrap_mode, pending_ranges);
return !is_bootstrap_mode && !pending_ranges;
});
}
bool storage_service::is_repair_based_node_ops_enabled(streaming::stream_reason reason) {
static const std::unordered_map<sstring, streaming::stream_reason> reason_map{
{"replace", streaming::stream_reason::replace},
{"bootstrap", streaming::stream_reason::bootstrap},
{"decommission", streaming::stream_reason::decommission},
{"removenode", streaming::stream_reason::removenode},
{"rebuild", streaming::stream_reason::rebuild},
};
auto enabled_list_str = _db.local().get_config().allowed_repair_based_node_ops();
std::vector<sstring> enabled_list = utils::split_comma_separated_list(std::move(enabled_list_str));
std::unordered_set<streaming::stream_reason> enabled_set;
for (const sstring& op : enabled_list) {
try {
auto it = reason_map.find(op);
if (it != reason_map.end()) {
enabled_set.insert(it->second);
} else {
throw std::invalid_argument(::format("unsupported operation name: {}", op));
}
} catch (...) {
throw std::invalid_argument(::format("Failed to parse allowed_repair_based_node_ops parameter [{}]: {}",
enabled_list_str, std::current_exception()));
}
}
bool global_enabled = _db.local().get_config().enable_repair_based_node_ops();
slogger.info("enable_repair_based_node_ops={}, allowed_repair_based_node_ops={{{}}}", global_enabled, fmt::join(enabled_set, " ,"));
return global_enabled && enabled_set.contains(reason);
}
node_ops_meta_data::node_ops_meta_data(
node_ops_id ops_uuid,
gms::inet_address coordinator,
std::list<gms::inet_address> ignore_nodes,
std::chrono::seconds watchdog_interval,
std::function<future<> ()> abort_func,
std::function<void ()> signal_func)
: _ops_uuid(std::move(ops_uuid))
, _coordinator(std::move(coordinator))
, _abort(std::move(abort_func))
, _abort_source(seastar::make_shared<abort_source>())
, _signal(std::move(signal_func))
, _ops(seastar::make_shared<node_ops_info>(_ops_uuid, _abort_source, std::move(ignore_nodes)))
, _watchdog([sig = _signal] { sig(); })
, _watchdog_interval(watchdog_interval)
{
slogger.debug("node_ops_meta_data: ops_uuid={} arm interval={}", _ops_uuid, _watchdog_interval.count());
_watchdog.arm(_watchdog_interval);
}
future<> node_ops_meta_data::abort() {
slogger.debug("node_ops_meta_data: ops_uuid={} abort", _ops_uuid);
_watchdog.cancel();
return _abort();
}
void node_ops_meta_data::update_watchdog() {
slogger.debug("node_ops_meta_data: ops_uuid={} update_watchdog", _ops_uuid);
if (_abort_source->abort_requested()) {
return;
}
_watchdog.cancel();
_watchdog.arm(_watchdog_interval);
}
void node_ops_meta_data::cancel_watchdog() {
slogger.debug("node_ops_meta_data: ops_uuid={} cancel_watchdog", _ops_uuid);
_watchdog.cancel();
}
shared_ptr<node_ops_info> node_ops_meta_data::get_ops_info() {
return _ops;
}
shared_ptr<abort_source> node_ops_meta_data::get_abort_source() {
return _abort_source;
}
future<> storage_service::node_ops_update_heartbeat(node_ops_id ops_uuid) {
slogger.debug("node_ops_update_heartbeat: ops_uuid={}", ops_uuid);
auto permit = co_await seastar::get_units(_node_ops_abort_sem, 1);
auto it = _node_ops.find(ops_uuid);
if (it != _node_ops.end()) {
node_ops_meta_data& meta = it->second;
meta.update_watchdog();
}
}
future<> storage_service::node_ops_done(node_ops_id ops_uuid) {
slogger.debug("node_ops_done: ops_uuid={}", ops_uuid);
auto permit = co_await seastar::get_units(_node_ops_abort_sem, 1);
auto it = _node_ops.find(ops_uuid);
if (it != _node_ops.end()) {
node_ops_meta_data& meta = it->second;
meta.cancel_watchdog();
_node_ops.erase(it);
}
}
future<> storage_service::node_ops_abort(node_ops_id ops_uuid) {
slogger.debug("node_ops_abort: ops_uuid={}", ops_uuid);
auto permit = co_await seastar::get_units(_node_ops_abort_sem, 1);
if (!ops_uuid) {
for (auto& [uuid, meta] : _node_ops) {
co_await meta.abort();
auto as = meta.get_abort_source();
if (as && !as->abort_requested()) {
as->request_abort();
}
}
_node_ops.clear();
co_return;
}
auto it = _node_ops.find(ops_uuid);
if (it != _node_ops.end()) {
node_ops_meta_data& meta = it->second;
slogger.info("aborting node operation ops_uuid={}", ops_uuid);
co_await meta.abort();
auto as = meta.get_abort_source();
if (as && !as->abort_requested()) {
as->request_abort();
}
_node_ops.erase(it);
} else {
slogger.info("aborting node operation ops_uuid={}: operation not found", ops_uuid);
}
}
void storage_service::node_ops_signal_abort(std::optional<node_ops_id> ops_uuid) {
if (ops_uuid) {
slogger.warn("Node operation ops_uuid={} watchdog expired. Signaling the operation to abort", ops_uuid);
}
_node_ops_abort_queue.push_back(ops_uuid);
_node_ops_abort_cond.signal();
}
future<> storage_service::node_ops_abort_thread() {
slogger.info("Started node_ops_abort_thread");
for (;;) {
co_await _node_ops_abort_cond.wait([this] { return !_node_ops_abort_queue.empty(); });
slogger.debug("Awoke node_ops_abort_thread: node_ops_abort_queue={}", _node_ops_abort_queue);
while (!_node_ops_abort_queue.empty()) {
auto uuid_opt = _node_ops_abort_queue.front();
_node_ops_abort_queue.pop_front();
try {
co_await node_ops_abort(uuid_opt.value_or(node_ops_id::create_null_id()));
} catch (...) {
slogger.warn("Failed to abort node operation ops_uuid={}: {}", *uuid_opt, std::current_exception());
}
if (!uuid_opt) {
slogger.info("Stopped node_ops_abort_thread");
co_return;
}
}
}
__builtin_unreachable();
}
} // namespace service