{"record":{"id":"5c497d242b4564ce","repo":"vitessio/vitess","slug":"failed-to-transition-from-state-s","errorCode":null,"errorMessage":"failed to transition from state %s","messagePattern":"failed to transition from state (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"go/vt/vtctl/grpcvtctldclient/client.go","lineNumber":124,"sourceCode":"\t\t\tconnState := client.cc.GetState()\n\n\t\t\tswitch connState {\n\t\t\tcase connectivity.Ready:\n\t\t\t\treturn nil\n\n\t\t\t// Per https://github.com/grpc/grpc/blob/master/doc/connectivity-semantics-and-api.md,\n\t\t\t// a client that enters the SHUTDOWN state never leaves this state, and all new RPCs should\n\t\t\t// fail immediately. Further polling is futile, in other words, and so we\n\t\t\t// return an error immediately to indicate that the caller can close the connection.\n\t\t\tcase connectivity.Shutdown:\n\t\t\t\treturn ErrConnectionShutdown\n\n\t\t\t// If the connection is IDLE, CONNECTING, or in a TRANSIENT_FAILURE mode,\n\t\t\t// then we wait to see if it will transition to a READY state.\n\t\t\tdefault:\n\t\t\t\tif !client.cc.WaitForStateChange(ctx, connState) {\n\t\t\t\t\t// If the client has failed to transition, fail so that the caller can close the connection.\n\t\t\t\t\treturn fmt.Errorf(\"failed to transition from state %s\", connState)\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\t}\n}\n\nfunc init() {\n\tvtctldclient.Register(\"grpc\", gRPCVtctldClientFactory)\n}\n","sourceCodeStart":106,"sourceCodeEnd":134,"githubUrl":"https://github.com/vitessio/vitess/blob/01a25a7d176f94613b8d59d799f438380a8760e4/go/vt/vtctl/grpcvtctldclient/client.go#L106-L134","documentation":"grpcvtctldclient.WaitForReady polls the gRPC channel state while trying to establish a connection to the vtctld server. If WaitForStateChange returns false — meaning the context was cancelled or the channel shut down — before reaching READY, it reports 'failed to transition from state %s'. This surfaces connection establishment failures (unreachable server, dial errors) as a state-transition error.","triggerScenarios":"Dialing a vtctld address that is down or wrong; context timeout/cancellation while the channel is IDLE, CONNECTING, or TRANSIENT_FAILURE; the ClientConn being closed during WaitForReady.","commonSituations":"vtctld not running or wrong port in VTDATARUN/vtctld config; network/firewall blocking the gRPC port; tests cancelling contexts too early; TLS mismatch causing TRANSIENT_FAILURE.","solutions":["Verify the vtctld server is running and the address/port is correct (e.g. `vtctldclient --server host:port GetSrvKeyspaces`).","Check the ctx deadline/cancellation and increase the timeout if needed.","Inspect gRPC TRANSIENT_FAILURE cause (TLS certs, DNS) in server/client logs.","Recreate the client if the ClientConn was closed by mistake."],"exampleFix":"// before\nctx := context.Background()\nclient.WaitForReady(ctx) // hangs or fails on dead server\n// after\nctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)\ndefer cancel()\nif err := client.WaitForReady(ctx); err != nil {\n    log.Warn(\"vtctld not ready\", slog.Any(\"error\", err))\n}","handlingStrategy":"retry","validationCode":"// pre-check connectivity before WaitForReady\nconn, err := grpc.NewClient(addr, opts...)\nif err != nil { return err }\nctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)\ndefer cancel()\n_ = conn\n","typeGuard":"func isTransitionFailure(err error) bool {\n    return err != nil && strings.Contains(err.Error(), \"failed to transition from state\")\n}","tryCatchPattern":"if err := client.WaitForReady(ctx); err != nil {\n    if isTransitionFailure(err) {\n        // check vtctld is up, then retry with backoff\n        return retryWithBackoff(ctx, client.WaitForReady)\n    }\n    return err\n}","preventionTips":["Always pass a context with a generous deadline to WaitForReady","Health-check the vtctld address/port before dialing","Verify TLS/credentials config matches the server","Recreate the ClientConn if it was closed earlier"],"tags":["grpc","connection","vtctld"],"backgroundTag":"grpc-connection-failure","analyzedSha":"01a25a7d176f94613b8d59d799f438380a8760e4","analyzedAt":"2026-09-01T17:28:30.605Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}