[Resolved] APC Fragmentation: should I care?

[gmichels]

Hi all,

I've been running APC for the last couple of weeks and it's making wonders for my site (IPB forum v3.1).

On busy periods I can see cache fragmentation getting on high values such as 30%-40%.

Here's a sample (non-busy moment) and my config settings:



I've set low TTL settings as a suggestion I've seen on the web.

Should I care about high fragmentation on the cache?

Thanks

[NiteWave]

to reduce the fragmentation, you may try apc.ttl = 0

http://php.net/manual/en/apc.configuration.php

apc.ttl integer
The number of seconds a cache entry is allowed to idle in a slot in case this cache entry slot is needed by another entry. Leaving this at zero means that APC's cache could potentially fill up with stale entries while newer entries won't be cached. In the event of a cache running out of available memory, the cache will be completely expunged if ttl is equal to 0. Otherwise, if the ttl is greater than 0, APC will attempt to remove expired entries.

also, try latest APC 3.1.4, to further tune and improve the php's performance.

[gmichels]

Here's the current status, 2 days uptime:



I'm going to try with a zero TTL.

How do I use APC 3.1.4 using the php compiler tool available on the web console?

Thanks

[NiteWave]

yes, 4.0.17 use APC 3.1.4

[gmichels]

Indeed setting the TTL at 0 helped with the fragmentation numbers, I don't see it above 5% anymore.

When I upgrade to 4.0.17 I'll try the newest APC.

Thanks for your help!