# rpc 错误：代码 = Unavailable 描述 = 没有健康的上游

- **ID:** `go/grpc-unavailable-load-balancer-no-backends`
- **领域:** go
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

负载均衡器或服务网格找不到任何健康的后端实例来路由请求。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.1 | active | — | — |

## 解决方案

1. **** (85% 成功率)
   ```
   // Configure health checks: grpc.HealthCheck(healthpb.NewHealthClient(conn))
   ```
2. **** (80% 成功率)
   ```
   // Configure destination rules with outlier detection.
   ```

## 无效尝试

- **** — Backends remain unhealthy; client restart doesn't fix server issues. (70% 失败率)
- **** — New replicas may also fail health checks due to same issue. (60% 失败率)