关键查询（从库）
关键查询（从库）
SELECT SERVICE_STATE FROM performance_schema.replication_connection_status; -- ON
SELECT SERVICE_STATE FROM performance_schema.replication_applier_status; -- ON
SELECT CHANNEL_NAME, SERVICE_STATE, LAST_ERROR_MESSAGE
FROM performance_schema.replication_applier_status_by_worker;告警项
| 指标 | 阈值建议 |
|---|---|
| IO/SQL 线程 | 任一非 ON 持续 60s |
| 延迟 | > 300s 持续 5 分钟 |
| Relay 积压 | 环比翻倍或超 10GB |
| 错误日志 | 出现复制错误码即告警 |
mysqld_exporter + Prometheus 是常见组合；P_S 表比解析 SHOW 文本稳定。