{"record":{"id":"045e072039e333b6","repo":"vitessio/vitess","slug":"unable-to-get-version-for-tablet-v-v","errorCode":null,"errorMessage":"unable to get version for tablet %v: %v","messagePattern":"unable to get version for tablet (.+?): (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"go/vt/vtctl/grpcvtctldserver/server.go","lineNumber":5838,"sourceCode":"\tdefer versionFuncMu.Unlock()\n\tgetVersionFromTablet = versionFunc\n}\n\nfunc GetVersionFunc() func(string) (string, error) {\n\tversionFuncMu.Lock()\n\tdefer versionFuncMu.Unlock()\n\treturn getVersionFromTablet\n}\n\n// helper method to asynchronously get and diff a version\nfunc (s *VtctldServer) diffVersion(ctx context.Context, primaryVersion string, primaryAlias *topodatapb.TabletAlias, alias *topodatapb.TabletAlias, wg *sync.WaitGroup, er concurrency.ErrorRecorder) {\n\tdefer wg.Done()\n\tlog.Info(fmt.Sprintf(\"Gathering version for %v\", topoproto.TabletAliasString(alias)))\n\treplicaVersion, err := s.GetVersion(ctx, &vtctldatapb.GetVersionRequest{\n\t\tTabletAlias: alias,\n\t})\n\tif err != nil {\n\t\ter.RecordError(fmt.Errorf(\"unable to get version for tablet %v: %v\", alias, err))\n\t\treturn\n\t}\n\n\tif primaryVersion != replicaVersion.Version {\n\t\ter.RecordError(fmt.Errorf(\"primary %v version %v is different than replica %v version %v\", topoproto.TabletAliasString(primaryAlias), primaryVersion, topoproto.TabletAliasString(alias), replicaVersion))\n\t}\n}\n\n// ApplyKeyspaceRoutingRules is part of the vtctlservicepb.VtctldServer interface.\nfunc (s *VtctldServer) ApplyKeyspaceRoutingRules(ctx context.Context, req *vtctldatapb.ApplyKeyspaceRoutingRulesRequest) (*vtctldatapb.ApplyKeyspaceRoutingRulesResponse, error) {\n\tspan, ctx := trace.NewSpan(ctx, \"VtctldServer.ApplyKeyspaceRoutingRules\")\n\tdefer span.Finish()\n\n\tspan.Annotate(\"skip_rebuild\", req.SkipRebuild)\n\tspan.Annotate(\"rebuild_cells\", strings.Join(req.RebuildCells, \",\"))\n\n\tresp := &vtctldatapb.ApplyKeyspaceRoutingRulesResponse{}\n","sourceCodeStart":5820,"sourceCodeEnd":5856,"githubUrl":"https://github.com/vitessio/vitess/blob/01a25a7d176f94613b8d59d799f438380a8760e4/go/vt/vtctl/grpcvtctldserver/server.go#L5820-L5856","documentation":"While validating that all replicas run the same vttablet build as the primary, GetVersion is called per replica; failures are recorded (not fatal) as \"unable to get version for tablet %v: %v\" in the validation error recorder.","triggerScenarios":"ValidateShard/ValidateKeyspace where GetVersion RPC to a replica alias fails — tablet down, restarting, or unreachable over gRPC.","commonSituations":"Replica is lagging back from a restart; alias belongs to a decommissioned tablet still in the topo; version-comparison runs during a rolling upgrade.","solutions":["Bring the failing replica tablet back up and re-run validation.","Remove stale/decommissioned tablet aliases from the shard.","Run version checks outside of rolling-upgrade windows, when all tablets are on the target version."],"exampleFix":null,"handlingStrategy":"fallback","validationCode":"tab, err := ts.GetTablet(ctx, alias); if err != nil { log.Warn(\"alias not in topo; exclude from version check\", slog.String(\"alias\", topoproto.TabletAliasString(alias))) }","typeGuard":null,"tryCatchPattern":"if err := client.ValidateShard(ctx, req); err != nil { if strings.Contains(err.Error(), \"unable to get version for tablet\") { /* treat per-tablet; retry that tablet individually after it recovers */ } }","preventionTips":["Run version checks when all replicas are healthy","Grep tablet logs for restarts before validation","Clean up stale tablet aliases routinely"],"tags":["tablet","version","validation","rpc"],"backgroundTag":"tablet-unreachable","analyzedSha":"01a25a7d176f94613b8d59d799f438380a8760e4","analyzedAt":"2026-09-01T17:28:30.605Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}