PHP caching

Latency is the most important part of speed

Cache strategies & levels

• Browser
• Content proxying
• Pre-generating content
• Active data caching
• Backend caches

APC is drop-in & use. It's old hat now.

Tweak APC if you have

• large # of files (>1024)
• Large footprint (>64M)
• a mess of include_onces
• highly OOP design
• very static PHP files
• rsync and inode re-use

APC tuneables apc.ini apc.shm_size (64M) apc.num_files_hint (512) apc.stat (On) apc.stat_ctime (Off) apc.include_once_override (Off) apc.filters () apc.localcache (Off)

APC monitoring Monitor using apc.php in the package

• memory usage
• fragmentation
• cache request/insert rates
• expunge/cache-full count

Reduce include/include_once calls

• Template & stitch
• R3 (http://rthree.sf.net/)

Use full include paths

• include("./z.php") instead of include("z.php")

Use constant includes, not include($foo)

• Don't wrap include with your functions

Avoid eval() at all costs

Inclued

• New extension he just wrote that maps out all the include mappings.

Update your cache out of band. cron & curl are APC's friends.

Always check APC info for cache full count and fragmentation