{"record":{"id":"cdf8e15a5825fb28","repo":"vitessio/vitess","slug":"error-dialing-vtgate-w","errorCode":null,"errorMessage":"error dialing vtgate: %w","messagePattern":"error dialing vtgate: %w","errorType":"error_code","errorClass":null,"httpStatus":null,"severity":"error","filePath":"go/vt/vtadmin/vtsql/vtsql.go","lineNumber":160,"sourceCode":"\tvtadminproto.AnnotateClusterSpan(vtgate.cluster, span)\n\tspan.Annotate(\"is_using_credentials\", vtgate.creds != nil)\n\n\tconf := vitessdriver.Configuration{\n\t\tProtocol:        \"grpc_\" + vtgate.cluster.Id,\n\t\tAddress:         resolver.DialAddr(vtgate.resolver, \"vtgate\"),\n\t\tTarget:          target,\n\t\tGRPCDialOptions: append(opts, grpc.WithTransportCredentials(insecure.NewCredentials()), grpc.WithResolvers(vtgate.resolver)),\n\t}\n\n\tif vtgate.creds != nil {\n\t\tconf.GRPCDialOptions = append([]grpc.DialOption{\n\t\t\tgrpc.WithPerRPCCredentials(vtgate.creds),\n\t\t}, conf.GRPCDialOptions...)\n\t}\n\n\tvtgate.conn, err = vtgate.dialFunc(conf)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"error dialing vtgate: %w\", err)\n\t}\n\n\tlog.Info(\"Established gRPC connection to vtgate\\n\")\n\n\tvtgate.m.Lock()\n\tdefer vtgate.m.Unlock()\n\n\tvtgate.closed = false\n\tvtgate.dialedAt = time.Now()\n\n\treturn nil\n}\n\n// ShowTablets is part of the DB interface.\nfunc (vtgate *VTGateProxy) ShowTablets(ctx context.Context) (*sql.Rows, error) {\n\tspan, ctx := trace.NewSpan(ctx, \"VTGateProxy.ShowTablets\")\n\tdefer span.Finish()\n","sourceCodeStart":142,"sourceCodeEnd":178,"githubUrl":"https://github.com/vitessio/vitess/blob/01a25a7d176f94613b8d59d799f438380a8760e4/go/vt/vtadmin/vtsql/vtsql.go#L142-L178","documentation":"The vtadmin vtsql package dials vtgate over gRPC when constructing a V3 connection (New -> dial). If the dial function (grpc.DialContext) returns an error — typically network or TLS-level — it is wrapped as 'error dialing vtgate'. This happens during client construction, before any query is executed.","triggerScenarios":"Creating a new vtsql connection (vtsql.New with Parse'd config) where vtgate is unreachable: wrong hostname/port, vtgate process down, TLS handshake failure, or DNS resolution failure in dialFunc.","commonSituations":"vtgate not running or restarted; wrong --vtctld/vtgate port in vtadmin config; firewall or NetworkPolicy blocking the gRPC port; certificate/key mismatch when TLS is enabled; DNS name not resolvable from the vtadmin pod.","solutions":["Confirm vtgate is running and the vtadmin config's hostname/port point at it (nc/curl the gRPC port).","If TLS is enabled, verify the CA cert, client cert/key, and server name match; check vtgate's -grpc_cert/-grpc_key flags.","Check DNS/network reachability from the vtadmin host/pod to the vtgate address.","Review dialFunc options and grpc.Dial timeout/lazy-connect behavior; with WithBlock semantics, connectivity errors surface here."],"exampleFix":"// before\nvtsql.New(ctx, cfg) // cfg.VtgateHost = \"vtgate:15991\" (stale port)\n// after\nvtsql.New(ctx, cfg) // cfg.VtgateHost = \"vtgate:15999\" (actual vtgate grpc port)","handlingStrategy":"retry","validationCode":"// Go: probe vtgate reachability before dialing\nfunc vtgateReachable(host string, port int, timeout time.Duration) bool {\n    conn, err := net.DialTimeout(\"tcp\", fmt.Sprintf(\"%s:%d\", host, port), timeout)\n    if err != nil { return false }\n    conn.Close()\n    return true\n}","typeGuard":null,"tryCatchPattern":"vtg, err := vtsql.New(ctx, cfg)\nif err != nil {\n    if strings.Contains(err.Error(), \"error dialing vtgate\") {\n        // backoff and retry; verify vtgate address/TLS in the meantime\n    }\n}","preventionTips":["Health-check vtgate's gRPC port before starting vtadmin (readiness probe).","Pin vtgate address/port in config and keep it in sync with the cluster's service discovery.","Verify TLS certs/CA match between vtadmin and vtgate when grpc is secured."],"tags":["network","grpc","vtgate","vtadmin"],"backgroundTag":"connection-refused","analyzedSha":"01a25a7d176f94613b8d59d799f438380a8760e4","analyzedAt":"2026-09-01T17:28:30.605Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}