Found in /var/log/syslog
Apr 28 10:43:07 atlantis amavis[1414]: (01414-07) NOTICE: reconnecting in response to: err=2006, HY000, DBD::mysql::st execute failed: MySQL server has gone away at (eval 114) line 166, <GEN156> line 5
This is not an error. Amavis is run as a daemon and sometimes MySQL server closes the connection that Amavis had opened if it is not used in a while.
If you do not like getting this error by OSSEC edit
/var/ossec/rules/local_rules.xml
and add this
blok inside <group name="local,syslog"> ...
</group>
block:
<rule id="100050" level="2"> <if_sid>1002</if_sid> <match>NOTICE: reconnecting in response to: err=2006, HY000, DBD::mysql::st execute failed: MySQL server has gone away at (eval 97) line 166</match> <description>Ignore Amavis complaining about MySQL going away</description> </rule>