I have a couple servers running apache2 service to hose REST APIs and traffic is descent. For now, apache2 is set to start 2 servers so I see two 222-data processes. Rarely, but from time to time, servers fails because of "scoreboard is full" error which is known Apache2 bug. When that happens I notice my processes are 4 not 2 and two of the processes are using 100%+ cpu, so I usually manually kill them and restart Apache2 which is not idea or reliable in long term.
I have read here and there aboutn setting up of MPM-Event.config to minimize errors like that and I even tried to update Apache2 on Ubuntu16 to 2.4.39. I looked up defauly MPM configs as below but not sure what is best change to minimze MPM errors. The post here has some suggestions but I am not as experienced with networking and specifically Apache2 and want to make sure I dont break production servers by applying changes suggested.
I am sure, the tuning changes are handled differently from one case to another, but I would appreciate any tips.
<IfModule mpm_event_module>
StartServers 2
MinSpareThreads 25
MaxSpareThreads 75
ThreadLimit 64
ThreadsPerChild 25
MaxRequestWorkers 150
MaxConnectionsPerChild 0
</IfModule>
