In this article you find a solution for Apache coredumps with OTRS or Znuny.
The common coredump issue
You get regularly Internal Server Errors like this during you are writing or sending new tickets, adding new notes or simply linking or merging tickets?
And in this moment you see in your /var/apache/error_log messages like this?
[core:notice] [pid 116:tid 14054] AH00051: child pid 116695 exit signal Segmentation fault (11), possible coredump in /etc/apache2
Distributions use a common multi processing module (MPM) as default for the default Apache package installation. E.g. under Ubuntu 20.04 the default setup of Apache is done with mpm_event module. But it could also be mpm_prefork or mpm_worker, depending on your distribution or Ubuntu version. To ensure that you have the right MPM active run this commands
a2dismod mpm_event a2dismod mpm_worker a2enmod mpm_prefork
And finally you need configure your /etc/apache2/mods-enabled/mpm_prefork.conf with values matching to your environment size. This config is e.g. for a small environment with about 50 users.
<IfModule mpm_prefork_module> StartServers 5 # how many servers shall be intialized on start MinSpareServers 5 # how many servers shall be free for new users MaxSpareServers 10 # how many server are allowed for new users to wait MaxRequestWorkers 50 # how many servers allowed to start at all, be careful with mem here! MaxConnectionsPerChild 100 # kill server after 100 connections to avoid mem leaks </IfModule>
If you have more users working in parallel on your OTRS/Znuny modify the servers and workers accordingly. But be careful to have enough RAM for your configuration! You can also read more about tuning here Performance-Tuning
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