Error log has INNODB MONITOR OUTPUT output every 20 seconds on one node

MySQL & MariaDB Percona XtraDB Cluster 5.x
1

I apologize if this is a pretty basic question, or even in the wrong place. The admin who previously maintained our Percona XtraDB cluster is no longer available, and I am learning quickly about the environment. Our second node in the cluster is dumping an INNODB MONITOR OUPUT every 20 seconds in the error log file, and I am trying to figure out why. I’ve read through several of the output chunks (~300 lines), and don’t see anything that indicates any sort of issue. I also don’t see anything in the configuration of the server that would cause this. I would appreciate any assistance to help figure out why the server is contstantly logging this to the error file, as it makes the error file more or less unusable, and is certainly using a good deal of disk space. Thanks,

Bob

2

I was also having this issue with 5.6.15-63.0 Percona XtraDB Cluster (GPL), Release 25.4, wsrep_25.4.r4043

I was able to fix it by running:

use ANY_DB;
CREATE TABLE innodb_monitor (a INT) ENGINE=INNODB;
DROP TABLE innodb_monitor;

I have no idea why it was enabled though.