Optimize APC Caching

Question

Hello, here is a link to how my APC is running : http://www.animefushigi.com/apc.php

As you can see, it fills up pretty quickly and my Cache Full Count goes over 1000 sometimes

My website uses Wordpress.

I notice that every time I make a new post or edit a post, 2 things happen.

1) APC Memory "USED" resets 2) I get a whole lot of Fragments

I've tried giving more Memory to APC (512 mb) but then it crashes sometimes, it seems 384 is best. I also have a Cron job that restarts apache, clearing all APC of fragments and used memory, every 4 hours. Again, my apache crashes if APC is running for a long period of time, I think due to the fragment buildup.

Should I use the apc.Filters and filter out some stuff that should not be cached?

I am really beginner at this sort of stuff, so if someone can explain with full instructions, Thank you very much !!!

Answer 1

The APC ttl should take care of fragment build up. I usually set it at 7200. I am running it on a small VPS with WordPress and my settings are:

apc.enabled=1
apc.shm_segments=3
apc.shm_size=32
apc.ttl=7200
apc.user_ttl=7200
apc.num_files_hint=2048
apc.mmap_file_mask=/tmp/apc.XXXXXX
apc.enable_cli=1
apc.max_file_size=10M

You will also get a lot more benefit from it by using WordPress's built in object cache and Mark Jaquith wrote a really good drop in plugin that should also help with some of your fragmentation issues when saving or editing a post.

Answer 2

You really should set apc.stat=0 on your production server and it will prevent APC from actually going to the IO to check if the file has been changed.

Check out documentation first: http://php.net/manual/en/apc.configuration.php