Apache2 MPM modules

[sapguy]

The basis of my question is a steadily upgraded 2.2rca (Ubuntu 20.04, PHP 7.2, Apache 2.4.x) currently running using the default prefork MPM (Multi-Process-Module) module. MPM is what allows us to have more than one concurrent user at a time.

• The prefork MPM module uses one thread for each and every process and is considered "thread safe". This takes a lot of memory as one thread consumes quite a bit of RAM, in the 3-4MB range for each thread.
• The worker MPM module allows multiple child processes within one thread, this will allow for a great number of additional concurrent users compared to prefork in terms of RAM consumption.
• Event MPM, similar to worker, I'll just leave it at that.

So I just started doing my research going from prefork --> worker and I through I'd check in here if anyone has any thoughts or experience around this. I realize each installation/configuration is different, of course. 

What it comes down to, from what I understand is whether or not OSC is thread safe or won't break in threading. Anyone know how to even proceed to test for this? 

Thanks in advance!

 

 

[♥ecartz]

It's not osCommerce that needs to be thread safe but PHP.  See https://serverfault.com/questions/904065/switch-apache-from-prefork-to-event-in-ubuntu-16-get-php-7-working for more discussion.  Note in particular that it switches from mod_php to the fast CGI PHP to use MPM Event.  At this point, you should probably target Event over Worker.  Both require a thread-safe PHP with only thread-safe PHP modules.