Using memcached to store the opcodes

[Jagriti]

Hello friends,

I know all opcode caches run only with php as an module or with a FastCGI setup because only in this cases the compiled opcodes can be
reused.But many hosters allow only CGI setups for security and stability reasons. If you want to use an opcode cache in such a setup
you have to store the opcodes outside the current process so that they survive the process termination and can be read by the next
process.With memcached there already exists a fast and stable in memory cache. So if XCache do its work but optionally use memcached
as memory backend for CGI setups.But it will be slower than writing direct to memory but am guessing for large applications it should give better performance than compiling all files in every request.does it makes sense?what you think?

thanks !!

[Reegan]

Normally APC uses shared memory to save its opcode cache. In the case of mod_php this memory is shared between all Apache processes.So a 30MB cache only takes up 30MB even if there are 5 Apache processes.However, when using mod_php, each Apache process does waste a lot of resources as each process contains the PHP interpreter. Thus, when Apache serves static content (html, css, js, image files, etc) it uses a process with the full PHP interpreter loaded. To get around this, some people use FastCGI via mod_fastcgi or mod_fcgi. Using an opcode cache with FastCGI becomes a bit trickier.

[kelfro]

I wish to get the best caching thing available so that my application is really fast. Obviously I don't want to over cache but I need to at least choose the best thing out there. In that article it says memcached is slow and apc is fast so why is everyone choosing memcached.APC Cache is Fast but it is not distributed so you’re wasting cache and reducing possible hit rate by caching things locally if you have many web servers. MemcacheD is relatively slow but distributed and so you do not waste memory by caching same item in a few places, it is also faster to warmup as you need only one access to bring item into the cache, not access for each of web servers.