My Custom APC configuration and custom settings

Today, after a log of changes and research I was finally able to find the best possible APC configuration for our office servers environment, here is how if looks like.

APC setup for performance

Edit your php.ini file after installing APC and add the following lines to the end of the file

[APC]
extension=apc.so
apc.enabled=1
apc.shm_segments=1

;example: 32M per website
apc.shm_size=128M

;Relative to the number of cached files (you may need to watch your stats for a day or two to find out a good number)
apc.num_files_hint=7000

;Relative to the size of the site
apc.user_entries_hint=4096

;The number of seconds a cache entry is allowed to idle in a slot before APC dumps the cache
apc.ttl=7200
apc.user_ttl=7200
apc.gc_ttl=3600

;Setting this to 0 will give you the best performance, as APC will
;not have to check the IO for changes. However, you must clear
;the APC cache to recompile already cached files. If you are still
;developing, updating your site daily in WP-ADMIN, and running W3TC
;set this to 1
apc.stat=1

apc.include_once_override=0

;Only set to 1 while debugging
apc.enable_cli=0

;Allow 2 seconds after a file is created before it is cached to prevent users from seeing half-written/weird pages
apc.file_update_protection=2

;Leave at 2M or lower. Sites like WordPress don't have any file sizes close to 2M
apc.max_file_size=2M

;Ignore files
apc.filters = "/var/www/apc.php"

apc.cache_by_default=1
apc.use_request_time=1
apc.slam_defense=0
apc.mmap_file_mask=/var/www/html/apc.XXXXXX
apc.stat_ctime=0
apc.canonicalize=1
apc.write_lock=1
apc.report_autofilter=0
apc.rfc1867=0
apc.rfc1867_prefix =upload_
apc.rfc1867_name=APC_UPLOAD_PROGRESS
apc.rfc1867_freq=0
apc.rfc1867_ttl=3600
apc.lazy_classes=0
apc.lazy_functions=0

While this configuration works great for us, it may not for you. There is endless customizable variables, like, “How much RAM, how many websites, do your websites support lazy classes and more… The best way to create your config is to do your own research.

Additionally to this APC configuration

There seems to be a lot of debate about apc.stat = 0.
The general thought is, set apc.stat=0 on production servers and it will prevent APC from actually going to the IO to check if the file has been changed. try your self and let me know how if goes.