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<p class="MsoNormal">Dear Mantainer,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We are experiencing a similar memory leak after porting an application from Debian 9 (mariadb 10.1.41-MariaDB-0+deb9u1) to Debian 11 (10.5.18-MariaDB-0+deb11u1)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">the mariadb memory footprint (/proc/pid/status:VmSize) at mariadb startup is 3GB, with innodb_buffer_pool_size=512 MB<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">The virtual memory growth rate is around 500-800 MB / day (compatible with the 33MB / hour mentioned by Xan Charbonnet)<o:p></o:p></li></ol>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Using the following query, we were able to attribute the memory growth to the database connections used by the emqx MQTT broker (configured for mysql authentication)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">SELECT id, db,command,progress,memory_used,max_memory_used,examined_rows, TIME, host, COMMAND from INFORMATION_SCHEMA.PROCESSLIST order by max_memory_used desc ;<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It seems that the only query being performed by emqx is quite simple:<o:p></o:p></p>
<p class="MsoNormal">select allow, ipaddr, username, clientid, access, topic from mqtt_acl where ipaddr = ? or username = ? or username = '$all' or clientid = ? order by allow asc<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">There are many other services using mariadb on the same machine, and they don’t show a similar memory growth according to the PROCESSLIST table.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">MAtteo<o:p></o:p></p>
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