XCache
From DreamHost
XCache is a PHP opcode cacher. It improves performance for PHP applications by caching compiled PHP code in memory for later requests.
More information can be found on the website: http://xcache.lighttpd.net/
Availability
XCache is an on-demand available option to DreamHost PS users, on a per-domain basis, or can be setup for all domains to use it.
Configuring XCache
If you can view XCache through phpinfo(), then you can configure it through a custom PHP.ini file by using the following settings:
[xcache]
; ini only settings, all the values here is default unless explained
; select low level shm/allocator scheme implemenation
xcache.shm_scheme = "mmap"
; to disable: xcache.size=0
; to enable : xcache.size=64M etc (any size > 0) and your system mmap allows
xcache.size = 64M
; set to cpu count (cat /proc/cpuinfo |grep -c processor)
xcache.count = 2
; just a hash hints, you can always store count(items) > slots
xcache.slots = 8k
; ttl of the cache item, 0=forever
xcache.ttl = 0
; interval of gc scanning expired items, 0=no scan, other values is in seconds
xcache.gc_interval = 0
; same as aboves but for variable cache
xcache.var_size = 0M
xcache.var_count = 1
xcache.var_slots = 8K
; default ttl
xcache.var_ttl = 0
xcache.var_maxttl = 0
xcache.var_gc_interval = 300
xcache.test = Off
; N/A for /dev/zero
xcache.readonly_protection = Off
; for *nix, xcache.mmap_path is a file path, not directory.
; Use something like "/tmp/xcache" if you want to turn on ReadonlyProtection
; 2 group of php won't share the same /tmp/xcache
; leave it blank(disabled) or "/tmp/phpcore/"
; make sure it's writable by php (without checking open_basedir)
xcache.coredump_directory = ""
; per request settings
xcache.cacher = On
xcache.stat = On
xcache.optimizer = On
[xcache.coverager]
; per request settings
; enable coverage data collecting for xcache.coveragedump_directory and xcache_$
xcache.coverager = Off
; ini only settings
; make sure it's readable (care open_basedir) by coverage viewer script
; requires xcache.coverager=On
xcache.coveragedump_directory = ""
It can be added after the Zend Optimizer settings.