# SENTINEL：仲裁节点不可达，故障转移延迟 30000ms

- **ID:** `redis/sentinel-arbiter-down-failover-delay`
- **领域:** redis
- **类别:** network_error
- **错误码:** `SENTINEL`
- **验证级别:** ai_generated
- **修复率:** 77%

## 根因

Sentinel 的仲裁节点不可达，导致无法达到故障转移所需的法定人数，从而造成延迟。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 6.2.0 | active | — | — |
| 7.0.0 | active | — | — |
| 7.2.0 | active | — | — |

## 解决方案

1. ```
   Check network connectivity from sentinel to arbiter: 'telnet <arbiter-ip> 26379' and ensure firewall rules allow traffic. If the arbiter is down, restart it and verify it rejoins the quorum: 'redis-cli -p 26379 SENTINEL CKQUORUM <mymaster>'
   ```
2. ```
   Temporarily reconfigure sentinel to use a different arbiter or increase the down-after-milliseconds to allow more time for arbiter recovery before failover is triggered
   ```

## 无效尝试

- **Increasing sentinel quorum to 2 to bypass arbiter requirement** — This reduces fault tolerance; if the arbiter is down but other nodes are up, failover may still be blocked if quorum is not met. (70% 失败率)
- **Restarting the arbiter node without checking network connectivity** — If the network between Sentinel and arbiter is partitioned, restarting alone won't fix the connectivity issue. (85% 失败率)
- **Removing the arbiter from the sentinel configuration** — This changes the quorum requirement and can lead to split-brain scenarios if the arbiter was intentionally placed there. (80% 失败率)