For a long time, I'm running PHP 7.1.x versions to run phpBB and the rest of my site. After my upgrade to phpBB3.3.0, I've switched to PHP7.3.15 (latest minor right now).
However... since that switch, my server has gone out of memory repeatedly, so I switched back, and problems went away.
So, I was wondering if anybody has similar experiences here?
Any idea how to find out what exactly is causing the issue?
The are no particular errors. All I see is a steady rise of memory usage by the PHP processes combined (which I monitor), with the server become accessible as a result.