{"record":{"id":"a3b3678653187652","repo":"vitessio/vitess","slug":"getschema-cluster-s-keyspace-s-tablet-s-a3b367","errorCode":null,"errorMessage":"GetSchema(cluster = %s, keyspace = %s, tablet = %s) failed: %w","messagePattern":"GetSchema\\(cluster = (.+?), keyspace = (.+?), tablet = (.+?)\\) failed: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"go/vt/vtadmin/cluster/cluster.go","lineNumber":1703,"sourceCode":"\t\t\treq.TableSizesOnly = sizesOnly\n\t\t\treq.TabletAlias = tablet.Tablet.Alias\n\n\t\t\tAnnotateSpan(c, span)\n\t\t\tannotateGetSchemaRequest(req, span)\n\t\t\tspan.Annotate(\"keyspace\", keyspace)\n\t\t\tspan.Annotate(\"shard\", tablet.Tablet.Shard)\n\n\t\t\tif err := c.schemaReadPool.Acquire(ctx); err != nil {\n\t\t\t\terr = fmt.Errorf(\"GetSchema(cluster = %s, keyspace = %s, tablet = %s) failed to acquire schemaReadPool: %w\", c.ID, keyspace, tablet.Tablet.Alias, err)\n\t\t\t\trec.RecordError(err)\n\t\t\t\treturn\n\t\t\t}\n\n\t\t\tresp, err := c.Vtctld.GetSchema(ctx, req)\n\t\t\tc.schemaReadPool.Release()\n\n\t\t\tif err != nil {\n\t\t\t\terr = fmt.Errorf(\"GetSchema(cluster = %s, keyspace = %s, tablet = %s) failed: %w\", c.ID, keyspace, tablet.Tablet.Alias, err)\n\t\t\t\trec.RecordError(err)\n\n\t\t\t\treturn\n\t\t\t}\n\n\t\t\tif resp == nil || resp.Schema == nil {\n\t\t\t\treturn\n\t\t\t}\n\n\t\t\tm.Lock()\n\t\t\tdefer m.Unlock()\n\n\t\t\tif !sizesOnly {\n\t\t\t\tschema.TableDefinitions = resp.Schema.TableDefinitions\n\t\t\t}\n\n\t\t\tif !opts.TableSizeOptions.AggregateSizes {\n\t\t\t\treturn","sourceCodeStart":1685,"sourceCodeEnd":1721,"githubUrl":"https://github.com/vitessio/vitess/blob/01a25a7d176f94613b8d59d799f438380a8760e4/go/vt/vtadmin/cluster/cluster.go#L1685-L1721","documentation":"When the Vtctld.GetSchema RPC for a specific tablet fails, vtadmin wraps the error with cluster ID, keyspace, and tablet alias and records it. Because the fan-out aggregates per-tablet errors, the overall GetSchema can partially succeed — the error names exactly which tablet's schema query failed.","triggerScenarios":"Vtctld.GetSchema RPC failure for one tablet: tablet down/restarting, mysqld unreachable from the tablet, vtctld timeout, or per-tablet ctx cancellation during the fan-out.","commonSituations":"A replica tablet being resynced/reparented during schema fetch; mysqld socket issues on one host; vtctld under load timing out on slow tablets; tablet drained or decommissioned mid-request.","solutions":["Read the recorded error to identify the failing tablet alias and wrapped cause","Check tablet health (vtctld GetTablets / tablet status page) and mysqld connectivity on that host","Retry GetSchema — healthy tablets' results are kept, only failed tablets need re-querying","Prefer querying a healthy replica/primary rather than a tablet in a transient state"],"exampleFix":null,"handlingStrategy":"retry","validationCode":"// Go: filter to healthy tablets before requesting schema\nhealthy := filterTablets(tablets, func(t *vtadminpb.Tablet) bool {\n\treturn t.Tablet.Type != topodatapb.TabletType_UNKNOWN && t.State == vtadminpb.Tablet_SERVING\n})","typeGuard":null,"tryCatchPattern":"schema, err := c.GetSchema(ctx, req)\nif err != nil {\n\t// error names the failing tablet alias\n\tvar alias string\n\tif _, scanErr := fmt.Sscanf(err.Error(), \"GetSchema(cluster = %*s keyspace = %*s tablet = %s\", &alias); scanErr == nil {\n\t\t// check/restart that tablet, then retry\n\t}\n\treturn err\n}","preventionTips":["Monitor tablet/mysqld health proactively","Avoid schema fetches during reparents and resyncs","Prefer primary or up-to-date replicas for schema reads","Aggregate per-tablet errors and retry only failed tablets"],"tags":["vtadmin","schema","vtctld","rpc"],"backgroundTag":"vtctld-rpc-failed","analyzedSha":"01a25a7d176f94613b8d59d799f438380a8760e4","analyzedAt":"2026-09-01T17:28:30.605Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}