The letters cease to be sent(MySql?)


#1

I am using the Docker version of Kanboard on Synology NAS, use worker and beanstalk.
At night, after starting the task “crond[15]: USER nginx pid 213 cmd cd /var/www/app && ./cli cronjob >/dev/null 2>&1”, the letters cease to be sent.

Errors in the logs:

2019-02-27T03:00:00.708295228Z crond[15]: USER nginx pid 213 cmd cd /var/www/app && ./cli cronjob >/dev/null 2>&1
2019-02-27T03:00:00.708688663Z crond[15]: USER root pid 214 cmd run-parts /etc/periodic/15min
2019-02-27T03:00:00.708743260Z crond[15]: USER root pid 215 cmd run-parts /etc/periodic/hourly
2019-02-27T03:00:04.962695473Z [27-Feb-2019 08:00:04 Asia/Yekaterinburg] PHP Warning: Error while sending QUERY packet. PID=14 in /var/www/app/libs/picodb/lib/PicoDb/StatementHandler.php on line 240
2019-02-27T03:00:04.963094636Z [27-Feb-2019 08:00:04 Asia/Yekaterinburg] [error] Kanboard\Core\Queue\JobHandler::executeJob: Error during job execution: SQL Error: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away
2019-02-27T03:00:04.963196686Z [27-Feb-2019 08:00:04 Asia/Yekaterinburg] [error] Kanboard\Core\Queue\JobHandler::executeJob => {“class”:“Kanboard\Job\EmailJob”,“params”:[“hiddenmail”,“hiddentext”]}
2019-02-27T03:00:05.039934215Z [27-Feb-2019 08:00:05 Asia/Yekaterinburg] [error] Kanboard\Core\Queue\JobHandler::executeJob: Error during job execution: SQL Error: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away
2019-02-27T03:00:05.040056460Z [27-Feb-2019 08:00:05 Asia/Yekaterinburg] [error] Kanboard\Core\Queue\JobHandler::executeJob => {“class”:“Kanboard\Job\EmailJob”,“params”:[“hiddenmail”,“hiddentext”]}

After restarting the container everything is restored.
What could be the problem?