XtraDB Cluster Version 5.5.29
Odd behaviour that cannot explain.
The wsrep_cluster_size variable we use to monitor (Nagios) the cluster as it is one of the status variables… obviously if the number of members drops we could have a problem or split brain so we need to know.
However we are seeing this value drop to zero, nothing in the errors logs on any node primary or otherwise explains it.
It happens on the primary, the numbers are fine on the other members.
You can get it to reset by restarting one of the members (not the primary). On a secondardy restart mysql and the number chnages say from 0 to n-1 and when the secondary is back goes to n where n is the number of members in the cluster.
Nothing seems to be wrong but as this creates alerts it is a concern.
Anyone else seeing this?