{"record":{"id":"5d249d5e5ce414ac","repo":"dgraph-io/dgraph","slug":"unable-to-reach-the-alpha-that-served-that-task","errorCode":null,"errorMessage":"unable to reach the Alpha that served that task","messagePattern":"unable to reach the Alpha that served that task","errorType":"error_code","errorClass":null,"httpStatus":null,"severity":"error","filePath":"worker/queue.go","lineNumber":62,"sourceCode":"\t}\n\n\t// Find the Alpha with the required Raft ID.\n\tvar addr string\n\tfor _, group := range groups().state.GetGroups() {\n\t\tfor _, member := range group.GetMembers() {\n\t\t\tif member.GetId() == raftId {\n\t\t\t\taddr = member.GetAddr()\n\t\t\t}\n\t\t}\n\t}\n\tif addr == \"\" {\n\t\treturn nil, fmt.Errorf(\"the Alpha that served that task is not available\")\n\t}\n\n\t// Send the request to the Alpha.\n\tpool, err := conn.GetPools().Get(addr)\n\tif err != nil {\n\t\treturn nil, errors.Wrapf(err, \"unable to reach the Alpha that served that task\")\n\t}\n\tclient := pb.NewWorkerClient(pool.Get())\n\treturn client.TaskStatus(ctx, req)\n}\n\n// TaskStatus retrieves metadata for a given task ID.\nfunc (*grpcWorker) TaskStatus(ctx context.Context, req *pb.TaskStatusRequest,\n) (*pb.TaskStatusResponse, error) {\n\ttaskId := req.GetTaskId()\n\tmeta, err := Tasks.get(taskId)\n\tif err != nil {\n\t\treturn nil, err\n\t}\n\n\tresp := &pb.TaskStatusResponse{TaskMeta: meta.uint64()}\n\treturn resp, nil\n}\n","sourceCodeStart":44,"sourceCodeEnd":80,"githubUrl":"https://github.com/dgraph-io/dgraph/blob/759e242be62c91f8d084da06ad0c8d21256d9c07/worker/queue.go#L44-L80","documentation":"The Alpha that served the task was found in membership (addr resolved), but conn.GetPools().Get(addr) failed to establish/get a connection pool to it; the error is wrapped with 'unable to reach the Alpha that served that task'. This is a network/connectivity failure to a specific cluster peer.","triggerScenarios":"Calling TaskStatusOverNetwork when the target Alpha at addr is down, restarting, unreachable due to network issues, or listening on a different port than the membership record says.","commonSituations":"The serving Alpha crashed after starting a backup; firewall or Kubernetes service blocking the internal gRPC port; stale address after a pod rescheduled to a new IP; TLS/ACL configuration mismatch between nodes.","solutions":["Retry after a short delay — the Alpha may be restarting or reconnecting","Verify the Alpha process is running and its gRPC port is reachable from this node (ping/nc)","Check membership records vs actual addresses (stale ZK/Zero entries) and correct them","Confirm TLS and ACL settings match across all Alphas"],"exampleFix":"// before\nmeta, _ := pb.TaskStatusOverNetwork(ctx, req)\n// after\nvar meta *pb.TaskStatusResponse\nvar err error\nfor i := 0; i < 5; i++ {\n    meta, err = pb.TaskStatusOverNetwork(ctx, req)\n    if err == nil { break }\n    time.Sleep(time.Duration(1<<i) * time.Second)\n}","handlingStrategy":"retry","validationCode":"// Pre-flight reachability check\nconn, err := net.DialTimeout(\"tcp\", addr, 2*time.Second)\nif err != nil { return fmt.Errorf(\"alpha %s unreachable: %w\", addr, err) }\nconn.Close()","typeGuard":null,"tryCatchPattern":"meta, err := worker.TaskStatusOverNetwork(ctx, req)\nvar nerr net.Error\nif err != nil && (errors.As(err, &nerr) || strings.Contains(err.Error(), \"unable to reach\")) {\n    time.Sleep(backoff)\n    meta, err = worker.TaskStatusOverNetwork(ctx, req)\n}","preventionTips":["Monitor Alpha liveness and internal gRPC port reachability","Keep Zero/membership addresses in sync with actual network addresses","Use retry with exponential backoff around cross-Alpha calls","Ensure TLS/ACL settings are identical on all Alphas"],"tags":["network","grpc","connectivity","dgraph"],"backgroundTag":"connection-refused","analyzedSha":"759e242be62c91f8d084da06ad0c8d21256d9c07","analyzedAt":"2026-09-01T14:42:12.034Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}