{
  "id": "go/grpc-unavailable-load-balancer",
  "signature": "rpc error: code = Unavailable desc = all SubConns are in TransientFailure",
  "signature_zh": "rpc错误：代码=不可用 描述=所有子连接均处于瞬态故障状态",
  "regex": "rpc\\ error:\\ code\\ =\\ Unavailable\\ desc\\ =\\ all\\ SubConns\\ are\\ in\\ TransientFailure",
  "domain": "go",
  "category": "network_error",
  "subcategory": null,
  "root_cause": "The gRPC client's load balancer cannot connect to any backend server because all endpoints are unreachable or failing health checks.",
  "root_cause_type": "generic",
  "root_cause_zh": "gRPC客户端的负载均衡器无法连接到任何后端服务器，因为所有端点都不可达或健康检查失败。",
  "versions": [
    {
      "version": "1.21",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "1.22",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "Recreating the client without changing server addresses.",
      "why_fails": "Same endpoints, same connectivity issue.",
      "fail_rate": 0.9,
      "condition": "",
      "sources": []
    },
    {
      "action": "Setting a shorter dial timeout.",
      "why_fails": "Timeouts don't fix unreachable servers.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Verify server health and restart any down instances.",
      "success_rate": 0.85,
      "how": "// Check server status via health check endpoint\nhealthClient := grpc_health_v1.NewHealthClient(conn)\nresp, err := healthClient.Check(ctx, &grpc_health_v1.HealthCheckRequest{Service: \"myservice.MyService\"})",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use a different load balancing policy like round_robin with proper service discovery.",
      "success_rate": 0.9,
      "how": "conn, _ := grpc.Dial(\"dns:///myservice:50051\", grpc.WithDefaultServiceConfig(`{\"loadBalancingPolicy\":\"round_robin\"}`))",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": null,
  "official_doc_section": null,
  "error_code": null,
  "verification_tier": "ai_generated",
  "confidence": 0.87,
  "fix_success_rate": 0.8,
  "resolvable": "true",
  "first_seen": "2024-08-10",
  "last_confirmed": "2025-01-01",
  "last_updated": "2025-01-01",
  "evidence_count": 0,
  "tags": [],
  "locale": "en",
  "aliases": []
}