Backport: MySQL version-aware reparent for PRS & ERS#866
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Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
Patch version differences within the same MySQL release do not affect replication compatibility, so the version-aware candidate election now ignores them. Only major.minor boundaries trigger the preference for a lower-version primary. Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com> Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
PRS always catches the elected tablet up to the old primary's exact demotion position, so replication position head-start is irrelevant for data safety. This change introduces SortMode (SortForPRS/SortForERS) to give PRS a distinct sort order: promotion rules > MySQL version > position > buffer pool > alias. ERS retains position-first ordering to minimize data loss. Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com> Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
- Remove unused `after.ServerVersion` assignment in StopReplicationAndGetStatus - Log warning when MySQL version string fails to parse - Clarify findCandidate post-loop comment explaining two-phase logic - Add v25 changelog entry with deployment note and cross-cell limitation Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com> Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
- Add `server_version` field to `PrimaryStatus` proto so that DemotePrimary and PrimaryStatus RPCs report the MySQL version - Populate version in PrimaryStatus, DemotePrimary, and StopReplicationAndGetStatus RPCs - Move GetVersionString call after replication stop in StopReplicationAndGetStatus to avoid delaying the critical path - Read PrimaryStatus.ServerVersion in ERS ERNotReplica path so demoted primary-status candidates no longer get unknownVersion - Extract getMySQLVersion helper to deduplicate the fetch-and-warn pattern across 4 call sites - Add test coverage for version propagation through both paths Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com> Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
ReleaseAtLeast already covers the same-release case (Minor >=), so the redundant IsSameRelease check can be removed. Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com> Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
StopReplicationAndGetStatus had several early-return paths (IO thread already stopped, replication not healthy, stop failures, after-status failure) that returned Before without populating ServerVersion. ERS builds its version map from Before.ServerVersion, so tablets hitting these paths became unknownVersion and could lose version-aware election to newer tablets. Fix: call getMySQLVersion(ctx) before every return that includes Before. Add a table-driven test covering all return paths (success and error) for both IOTHREADONLY and IOANDSQLTHREAD modes. Ref: vitessio#20211 (review) Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com> Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
The cherry-picked test case references a primaryAlias struct field that doesn't exist on the slack-22.0 branch. Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com>
Trace version detection and candidate selection so we can verify the lowest-version preference is working as intended in production. Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com>
The successful stop path set Before.ServerVersion but left After.ServerVersion empty, while the no-op paths return After: before and thus include it. Set after.ServerVersion = before.ServerVersion so the common success path is consistent, and extend the test to assert After.ServerVersion when present. Co-Authored-By: Claude <svc-devxp-claude@slack-corp.com> Signed-off-by: Eduardo Ortega <5791035+ejortegau@users.noreply.github.com>
This reverts commit 4bfe9c5.
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What's this?
Backport of the MySQL version-aware primary selection feature for PRS and ERS from upstream PR vitessio#20211.
When selecting a new primary during reparenting, this now prefers tablets running a lower MySQL release (major.minor) to maintain replication compatibility — replicas must be at the same or higher version than the primary.
How it works
server_versionfield to the replication status proto, populated duringStopReplicationAndGetStatussortTabletsForReparentto consider MySQL version after promotion rulesidentifyPrimaryCandidate, among same-tier candidates prefers the lowest MySQL releaseDifferences from upstream
log.Warningfinstead of structuredlog.Warn(slack-22.0 doesn't have the new logging)Cherry-picked and adapted by Claude Code from upstream commits.