Stop INNODB MONITOR OUTPUT I use MariaDB galera cluster 10.0.31 with 3 nodes.

In one node when I tail -f err log to monitor server, Every 20 seconds MySQL dumping Show InnoDB Status to err log, and the log are getting bigger.

I don't know Which variable cause to dump output Innodb status to Err log file!
The variable you're looking for is innodb_status_output.  Setting it to OFF should stop the innodb status from being dumped into the error log.