bahman/scylla
1
0
Fork 0
Code Issues Pull Requests Actions 2 Packages Projects Releases Wiki Activity

tablets: load_balancer: Print rack in addition to DC when giving context

Browse Source 
Load-balancing can be now per-rack instead of per-DC. So just printing
"in DC" is confusing. If we're balancing a rack, we should print which
rack is that.
This commit is contained in:
Tomasz Grabiec
2026-01-20 14:58:36 +01:00
parent df32318f66
commit f2b0146f0f
1 changed files with 6 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
service/tablet_allocator.cc
View File

@@ -903,6 +903,7 @@ class load_balancer {
absl::flat_hash_map<table_id, uint64_t> _disk_used_per_table;
dc_name _dc;
std::optional<sstring> _rack; // Set when plan making is limited to a single rack.
sstring _location; // Name of the current scope of plan making. DC or DC+rack.
size_t _total_capacity_shards; // Total number of non-drained shards in the balanced node set.
size_t _total_capacity_nodes; // Total number of non-drained nodes in the balanced node set.
uint64_t _total_capacity_storage; // Total storage of non-drained nodes in the balanced node set.
@@ -3396,7 +3397,7 @@ public:
// If there are 7 tablets and RF=3, each node must have 1 tablet replica.
// So node3 will have average load of 1, and node1 and node2 will have
// average shard load of 7.
lblogger.info("Not possible to achieve balance.");
lblogger.info("Not possible to achieve balance in {}", _location);
}
co_return std::move(plan);
@@ -3462,6 +3463,7 @@ public:
_dc = dc;
_rack = rack;
_location = fmt::format("{}{}", dc, rack ? fmt::format("/{}", *rack) : "");
auto node_filter = [&] (const locator::node& node) {
return node.dc_rack().dc == dc && (!rack || node.dc_rack().rack == *rack);
@@ -3631,8 +3633,8 @@ public:
});
if (!has_dest_nodes) {
for (auto host : nodes_to_drain) {
plan.add(drain_failure(host, format("No candidate nodes in DC {} to drain {}."
" Consider adding new nodes or reducing replication factor.", dc, host)));
plan.add(drain_failure(host, format("No candidate nodes in {} to drain {}."
" Consider adding new nodes or reducing replication factor.", _location, host)));
}
lblogger.debug("No candidate nodes");
_stats.for_dc(dc).stop_no_candidates++;
@@ -3815,7 +3817,7 @@ public:
if (_tm->tablets().balancing_enabled() && plan.empty() && !ongoing_rack_list_colocation()) {
auto dc_merge_plan = co_await make_merge_colocation_plan(dc, nodes);
auto level = dc_merge_plan.tablet_migration_count() > 0 ? seastar::log_level::info : seastar::log_level::debug;
lblogger.log(level, "Prepared {} migrations for co-locating sibling tablets in DC {}", dc_merge_plan.tablet_migration_count(), dc);
lblogger.log(level, "Prepared {} migrations for co-locating sibling tablets in {}", dc_merge_plan.tablet_migration_count(), _location);
plan.merge(std::move(dc_merge_plan));
}