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

locator: everywhere_replication_strategy: fix sanity_check_read_replicas when read_new is true

Browse Source 
ERMs created in `calculate_vnode_effective_replication_map` have RF computed based
on the old token metadata during a topology change. The reading replicas, however,
are computed based on the new token metadata (`target_token_metadata`) when
`read_new` is true. That can create a mismatch for EverywhereStrategy during some
topology changes - RF can be equal to the number of reading replicas +-1. During
bootstrap, this can cause the
`everywhere_replication_strategy::sanity_check_read_replicas` check to fail in
debug mode.

We fix the check in this commit by allowing one more reading replica when
`read_new` is true.

Fixes https://scylladb.atlassian.net/browse/SCYLLADB-1147

Closes scylladb/scylladb#29150

(cherry picked from commit 503a6e2d7e)

Closes scylladb/scylladb#29248
This commit is contained in:
Patryk Jędrzejczak
2026-03-20 12:48:00 +01:00
parent 233da83dd9
commit b176591488
1 changed files with 8 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
locator/everywhere_replication_strategy.cc
View File

@@ -42,7 +42,14 @@ void everywhere_replication_strategy::validate_options(const gms::feature_servic
sstring everywhere_replication_strategy::sanity_check_read_replicas(const effective_replication_map& erm, const host_id_vector_replica_set& read_replicas) const {
const auto replication_factor = erm.get_replication_factor();
if (read_replicas.size() > replication_factor) {
if (const auto& topo_info = erm.get_token_metadata().get_topology_change_info(); topo_info && topo_info->read_new) {
if (read_replicas.size() > replication_factor + 1) {
return seastar::format(
"everywhere_replication_strategy: the number of replicas for everywhere_replication_strategy is {}, "
"cannot be higher than replication factor {} + 1 during the 'read from new replicas' stage of a topology change",
read_replicas.size(), replication_factor);
}
} else if (read_replicas.size() > replication_factor) {
return seastar::format("everywhere_replication_strategy: the number of replicas for everywhere_replication_strategy is {}, cannot be higher than replication factor {}", read_replicas.size(), replication_factor);
}
return {};