# SENTINEL: arbiter node timeout, failover aborted for master 'mymaster'

- **ID:** `redis/sentinel-arbiter-timeout-failover`
- **Domain:** redis
- **Category:** network_error
- **Error Code:** `SENTINEL`
- **Verification:** ai_generated
- **Fix Rate:** 78%

## Root Cause

A Sentinel arbiter node failed to respond within the configured timeout during a failover vote, preventing quorum from being reached.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 6.2 | active | — | — |
| 7.0 | active | — | — |
| 7.2 | active | — | — |

## Workarounds

1. **Increase the sentinel failover-timeout to give the arbiter more time to respond. Example: SENTINEL SET mymaster failover-timeout 60000 (from 30000 ms default)** (80% success)
   ```
   Increase the sentinel failover-timeout to give the arbiter more time to respond. Example: SENTINEL SET mymaster failover-timeout 60000 (from 30000 ms default)
   ```
2. **Check network connectivity between the Sentinel nodes and the arbiter; reduce latency by ensuring they are in the same datacenter or use a faster network path.** (85% success)
   ```
   Check network connectivity between the Sentinel nodes and the arbiter; reduce latency by ensuring they are in the same datacenter or use a faster network path.
   ```
3. **If the arbiter is unreliable, replace it with a more stable Sentinel instance or remove it from the sentinel monitor configuration.** (75% success)
   ```
   If the arbiter is unreliable, replace it with a more stable Sentinel instance or remove it from the sentinel monitor configuration.
   ```

## Dead Ends

- **Increase the sentinel monitor quorum to a higher value to require more votes.** — This increases the required votes but does not fix the arbiter timeout; it may make failover even harder. (60% fail)
- **Set all Sentinels to have equal weight by removing arbiter designation.** — Arbiters are a concept in some setups; in Redis Sentinel, all nodes vote equally, and removing designation does not address timeout. (70% fail)
- **Restart the arbiter Sentinel node to clear its state.** — If the timeout is due to network or resource issues, restarting provides only temporary relief. (50% fail)