# MaxScale 25.10.4 logs (both instances merged), same window. mariadbmon issues STOP SLAVE on core-db-1 at 18:21:38 and 18:22:49. Router noise removed.
2026-10-30T18:21:01.254642101Z 2026-10-30 18:21:01   error  : Monitor was unable to connect to server core-db-0[core-db-0.core-db-internal.noop.svc.cluster.local:3306] : 'Connection to [core-db-0.core-db-internal.noop.svc.cluster.local]:3306 failed. Error 2002: Can't connect to server on 'core-db-0.core-db-internal.noop.svc.cluster.local' (115)'
2026-10-30T18:21:01.265762762Z 2026-10-30 18:21:01   notice : [mariadbmon] 'mariadbmon-monitor' acquired the exclusive lock on a majority of its servers. Configured automatic cluster manipulation operations (e.g. failover) can be performed in 5 monitor ticks.
2026-10-30T18:21:01.265867812Z 2026-10-30 18:21:01   notice : Server changed state: core-db-0[core-db-0.core-db-internal.noop.svc.cluster.local:3306]: master_down. [Master, Running] -> [Down]
2026-10-30T18:21:02.334651256Z 2026-10-30 18:21:02   error  : (ConfigManager); Failed to sync configuration: No valid servers in cluster 'mariadbmon-monitor'.
2026-10-30T18:21:38.644670447Z 2026-10-30 18:21:38   notice : [mariadbmon] Selecting a server to promote and replace 'core-db-0'. Candidates are: 'core-db-1', 'core-db-2'.
2026-10-30T18:21:38.645864287Z 2026-10-30 18:21:38   notice : [mariadbmon] Selected 'core-db-1'.
2026-10-30T18:21:38.645871592Z 2026-10-30 18:21:38   notice : [mariadbmon] Performing automatic failover to replace failed primary 'core-db-0'.
2026-10-30T18:21:45.831869925Z 2026-10-30 18:21:45   error  : [mariadbmon] Failed to stop replica connection on 'core-db-1': Query 'SET STATEMENT max_statement_time=6 FOR STOP SLAVE '';' failed on core-db-1. Error 2026: TLS/SSL error: Connection timed out (110).
2026-10-30T18:21:45.831900365Z 2026-10-30 18:21:45   error  : [mariadbmon] Failed to remove replica connection(s) from 'core-db-1'.
2026-10-30T18:21:45.843932852Z 2026-10-30 18:21:45   error  : [mariadbmon] Failover 'core-db-0' -> 'core-db-1' failed.
2026-10-30T18:21:45.843965638Z 2026-10-30 18:21:45   notice : [mariadbmon] Disabling automatic cluster operations for 5 monitor ticks.
2026-10-30T18:21:45.949094325Z 2026-10-30 18:21:45   warning: [mariadbmon] Lost the lock maxscale_mariadbmonitor on core-db-1 due to a reconnection. The lock is now owned by connection 28.
2026-10-30T18:21:52.950917153Z 2026-10-30 18:21:52   warning: [mariadbmon] 'mariadbmon-monitor' lost the exclusive lock on a majority of its servers. Configured automatic cluster manipulation operations (e.g. failover) can not be performed.
2026-10-30T18:21:52.950947133Z 2026-10-30 18:21:52   warning: [mariadbmon] 'mariadbmon-monitor' holds 1 exclusive server lock(s) out of 2 required for lock majority, and will release them. 1 lock(s) could not be acquired because server is down. 1 lock(s) were held by another MaxScale. Will try to reacquire locks later if majority is possible.
2026-10-30T18:21:52.951783282Z 2026-10-30 18:21:52   notice : Server changed state: core-db-1[core-db-1.core-db-internal.noop.svc.cluster.local:3306]: lost_slave. [Slave, Running] -> [Running]: Host: [core-db-0.core-db-internal.noop.svc.cluster.local]:3306, IO Running: Connecting, SQL Running: No, IO Error: error reconnecting to master 'repl@core-db-0.core-db-internal.noop.svc.cluster.local:3306' - retry-time: 5  maximum-retries: 100000  message: Can't connect to server on 'core-db-0.core-db-internal.noop.svc.cluster.local' (111 "Connection refused")
2026-10-30T18:22:00.062803984Z 2026-10-30 18:22:00   error  : [mariadbmon] Failed to acquire lock on server 'core-db-1'. Query 'SET @@session.wait_timeout=16; SELECT GET_LOCK('maxscale_mariadbmonitor', 0);' failed. Error 2002: Can't connect to server on 'core-db-1.core-db-internal.noop.svc.cluster.local' (115).
2026-10-30T18:22:00.062843563Z 2026-10-30 18:22:00   warning: [mariadbmon] 'mariadbmon-monitor' holds 1 exclusive server lock(s) out of 2 required for lock majority, and will release them. 1 lock(s) could not be acquired because server is down. Will try to reacquire locks later if majority is possible.
2026-10-30T18:22:00.166474842Z 2026-10-30 18:22:00   error  : Monitor was unable to connect to server core-db-1[core-db-1.core-db-internal.noop.svc.cluster.local:3306] : 'Connection to [core-db-1.core-db-internal.noop.svc.cluster.local]:3306 failed. Error 2002: Can't connect to server on 'core-db-1.core-db-internal.noop.svc.cluster.local' (115)'
2026-10-30T18:22:07.170645998Z 2026-10-30 18:22:07   notice : Server changed state: core-db-1[core-db-1.core-db-internal.noop.svc.cluster.local:3306]: server_down. [Running] -> [Down]
2026-10-30T18:22:14.277434906Z 2026-10-30 18:22:14   notice : [mariadbmon] 'mariadbmon-monitor' acquired the exclusive lock on a majority of its servers. Configured automatic cluster manipulation operations (e.g. failover) can be performed in 5 monitor ticks.
2026-10-30T18:22:14.277457882Z 2026-10-30 18:22:14   notice : Server changed state: core-db-1[core-db-1.core-db-internal.noop.svc.cluster.local:3306]: slave_up. [Down] -> [Slave, Running]
2026-10-30T18:22:49.810880794Z 2026-10-30 18:22:49   notice : [mariadbmon] Selecting a server to promote and replace 'core-db-0'. Candidates are: 'core-db-1', 'core-db-2'.
2026-10-30T18:22:49.813881234Z 2026-10-30 18:22:49   notice : [mariadbmon] Selected 'core-db-1'.
2026-10-30T18:22:49.813897266Z 2026-10-30 18:22:49   notice : [mariadbmon] Performing automatic failover to replace failed primary 'core-db-0'.
2026-10-30T18:22:55.670510765Z 2026-10-30 18:22:55   notice : [mariadbmon] Redirecting 'core-db-2' to replicate from 'core-db-1' instead of 'core-db-0'.
2026-10-30T18:23:02.345825842Z 2026-10-30 18:23:02   notice : [mariadbmon] All redirects successful.
2026-10-30T18:23:02.847889124Z 2026-10-30 18:23:02   notice : [mariadbmon] All redirected slaves successfully started replication from 'core-db-1'.
2026-10-30T18:23:02.848564268Z 2026-10-30 18:23:02   notice : [mariadbmon] Failover 'core-db-0' -> 'core-db-1' performed.
2026-10-30T18:23:09.857554656Z 2026-10-30 18:23:09   notice : Server changed state: core-db-1[core-db-1.core-db-internal.noop.svc.cluster.local:3306]: new_master. [Slave, Running] -> [Master, Running]