I recently moved my site to a new server (Apache 2, PHP5, MySQL5). The site is an Invision based forum. Every few posts / topics it just hangs. The data has been written because if you stop and reload, the post / thread is there. I thought it was a write issue initially, but nope. The data is written but the page load never completes. It doesn't leave the page where the data has been input.
What's the best way to troubleshoot this issue? The only thing I have done recently is reduce my MySQL timeouts, but I can't see that being an issue as the values are still big enough and there are no mentions of timeouts in the MySQL log. For the record there is nothing in PHP's error log either.
EDIT: I checked my server-status. It all looked ok, but I have a suspicion I was hitting my ServerLimit, so I doubled that. Also enabled my Keepalives. Will keep an eye on it.
EDIT 2: It's now been a few days and this is still occuring. I have more info though;
- Apache is throwing seg faults, but enabling core dumps does not produce them.
- I have tried disabling the modules in apache but it just stops things from working.
- I fear it may actually be DNS related. If I watch Live Headers in Firefox, absolutely nothing happens during this 'hanging' period. After that, the responses come back fairly promptly.
UPDATE (05/04): I built the latest versions of Apache and PHP from source, no luck. I then removed those and used the remi repo to update all my packages to the latest stable. Segfaults seem to have stopped, but the hanging is continuing.
ini's are at:
UPDATE - SOLVED! - The issue was having a gigantic query cache size in MySQL. It was 2GB, changing it to 64M sorted it.