bahman/scylla
1
0
Fork 0
Code Issues Pull Requests Actions 3 Packages Projects Releases Wiki Activity

virtual_tables: scope virtual tables registry in system_keyspace

Browse Source 
Virtual tables are kept in a thread_local registry for deduplication
purposes. The problem is that thread_local variables are destroyed late,
possibly after the schema registry and the reactor are destroyed.
Currently this isn't a problem, but after a seastar change to
destroy the reactor after termination [1], things break.

Fix by moving the registry to system_keyspace. system_keyspace was chosen
since it was the birthplace of virtual tables.

Pimpl is used to avoid increasing dependencies.

[1] 101b245ed7
This commit is contained in:
Avi Kivity
2023-12-21 16:19:42 +02:00
parent ee203f846e
commit 2853f79f96
3 changed files with 27 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
db/system_keyspace.hh
View File

@@ -24,6 +24,7 @@
#include "cdc/generation_id.hh"
#include "locator/host_id.hh"
#include "mutation/canonical_mutation.hh"
#include "virtual_tables.hh"
namespace sstables {
struct entry_descriptor;
@@ -112,6 +113,7 @@ class system_keyspace : public seastar::peering_sharded_service<system_keyspace>
cql3::query_processor& _qp;
replica::database& _db;
std::unique_ptr<local_cache> _cache;
virtual_tables_registry _virtual_tables_registry;
static schema_ptr raft_snapshot_config();
static schema_ptr local();
@@ -521,6 +523,7 @@ public:
~system_keyspace();
future<> shutdown();
virtual_tables_registry& get_virtual_tables_registry() { return _virtual_tables_registry; }
private:
future<::shared_ptr<cql3::untyped_result_set>> execute_cql(const sstring& query_string, const std::initializer_list<data_value>& values);
template <typename... Args>

17
db/virtual_tables.cc
View File

@@ -982,11 +982,8 @@ private:
}
// Map from table's schema ID to table itself. Helps avoiding accidental duplication.
static thread_local std::map<table_id, std::unique_ptr<virtual_table>> virtual_tables;
static void register_virtual_tables(distributed<replica::database>& dist_db, distributed<service::storage_service>& dist_ss, sharded<gms::gossiper>& dist_gossiper, sharded<service::raft_group_registry>& dist_raft_gr, db::config& cfg) {
auto add_table = [] (std::unique_ptr<virtual_table>&& tbl) {
static void register_virtual_tables(virtual_tables_registry_impl& virtual_tables, distributed<replica::database>& dist_db, distributed<service::storage_service>& dist_ss, sharded<gms::gossiper>& dist_gossiper, sharded<service::raft_group_registry>& dist_raft_gr, db::config& cfg) {
auto add_table = [&] (std::unique_ptr<virtual_table>&& tbl) {
virtual_tables[tbl->schema()->id()] = std::move(tbl);
};
@@ -1007,6 +1004,7 @@ static void register_virtual_tables(distributed<replica::database>& dist_db, dis
}
static void install_virtual_readers_and_writers(db::system_keyspace& sys_ks, replica::database& db) {
auto& virtual_tables = *sys_ks.get_virtual_tables_registry();
db.find_column_family(system_keyspace::size_estimates()).set_virtual_reader(mutation_source(db::size_estimates::virtual_reader(db, sys_ks)));
db.find_column_family(system_keyspace::v3::views_builds_in_progress()).set_virtual_reader(mutation_source(db::view::build_progress_virtual_reader(db)));
db.find_column_family(system_keyspace::built_indexes()).set_virtual_reader(mutation_source(db::index::built_indexes_virtual_reader(db)));
@@ -1023,7 +1021,9 @@ future<> initialize_virtual_tables(
sharded<gms::gossiper>& dist_gossiper, distributed<service::raft_group_registry>& dist_raft_gr,
sharded<db::system_keyspace>& sys_ks,
db::config& cfg) {
register_virtual_tables(dist_db, dist_ss, dist_gossiper, dist_raft_gr, cfg);
auto& virtual_tables_registry = sys_ks.local().get_virtual_tables_registry();
auto& virtual_tables = *virtual_tables_registry;
register_virtual_tables(virtual_tables, dist_db, dist_ss, dist_gossiper, dist_raft_gr, cfg);
auto& db = dist_db.local();
for (auto&& [id, vt] : virtual_tables) {
@@ -1034,4 +1034,9 @@ future<> initialize_virtual_tables(
install_virtual_readers_and_writers(sys_ks.local(), db);
}
virtual_tables_registry::virtual_tables_registry() : unique_ptr(std::make_unique<virtual_tables_registry_impl>()) {
}
virtual_tables_registry::~virtual_tables_registry() = default;
} // namespace db

13
db/virtual_tables.hh
View File

@@ -10,6 +10,7 @@
#pragma once
#include <seastar/core/distributed.hh>
#include <map>
#include "schema/schema_fwd.hh"
namespace replica {
@@ -38,4 +39,16 @@ future<> initialize_virtual_tables(
sharded<db::system_keyspace>& sys_ks,
db::config&);
class virtual_table;
using virtual_tables_registry_impl = std::map<table_id, std::unique_ptr<virtual_table>>;
// Pimpl to hide virtual_table from the rest of the code
class virtual_tables_registry : public std::unique_ptr<virtual_tables_registry_impl> {
public:
virtual_tables_registry();
~virtual_tables_registry();
};
} // namespace db