wsrep_flow_control_paused gets pretty high sometimes

MySQL & MariaDB Percona XtraDB Cluster 5.x
1

I have a 3 node percona xtradb cluster, and im getting about a couple of messages per day from nagios complaining about wsrep_flow_control_paused being >0.1 - is this expected? it is supposed to be strictly 0? i already increased the number of slave threads per instructed here:
[url]http://support.severalnines.com/entries/22265901-Interpreting-the-Status-of-Galera-Cluster-for-MySQL-[/url]

cheers, --Ricardo

2

a value of 0.1 indicates that flow control was in effect for 10% of the time since the last SHOW GLOBAL STATUS. This isn’t that helpful, because you may not know when that was.

In general flow control is normal, but you do want to be careful to understand what is causing it and try to tune to avoid it getting too high. See my blog post on the subject here: [url]http://www.mysqlperformanceblog.com/2013/05/02/galera-flow-control-in-percona-xtradb-cluster-for-mysql/[/url]