2006 MySQL server has gone away

In the last couple of weeks we have been experiencing a 2006 MySQL server has gone away error intermittently on our servers, to allow connections again we run “FLUSH TABLES”. (we have this running on a cron to maintain stability at the moment)

We have upgraded to from MySQL 5.6.5 to MySQL 5.6.22 and switched now to Percona 5.6.21-70.

Server Mac Mini Core i7 16GB RAM 512GB Enterprise SSD.

ulimit -a

NB - This config has been tinkered with by many people over the years - My hunch is the problem lays within here…
This is used in MM Replication environment.

ShowStatus.txt (10.7 KB)

Config.txt (14.8 KB)