# rpc 错误：代码 = Canceled，描述 = 上下文已取消

- **ID:** `go/grpc-stream-canceled-by-client`
- **领域:** go
- **类别:** network_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

在 RPC 返回前，调用方的上下文被取消（客户端超时、用户请求中止或上游上下文传播）。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.40+ | active | — | — |

## 解决方案

1. **** (85% 成功率)
   ```
   Create a fresh context for retries with a bounded deadline:
retryCtx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
defer cancel()
resp, err := client.Do(retryCtx, req)
   ```
2. **** (90% 成功率)
   ```
   On the server, honor ctx.Done() and clean up resources:
<-ctx.Done()
// release DB conn, cancel downstream calls
   ```

## 无效尝试

- **** — A canceled context stays canceled; the retry fails immediately. (95% 失败率)
- **** — Masks upstream cancellation and can leak goroutines / leave server resources allocated. (70% 失败率)