Re: Re: [Proposal] New Extension Yac (a user data cache base on shared memory without locks)

On 23/03/13 09:46, Matīss Roberts Treinis wrote:

Memcached is distributed caching system, where as APC's user data cache is not. Memcached requires separate server instance (memcached) to operate. APC does not. Yes, but there is nothing to stop an admin of an application-dedicated system or VM configuring and using an in-server memcached.

Also, APC's user cache is 5+ times faster than memcached. If some extension is to provide this functionality, it has to be as close as possible in possibilities and speed as APC's implementation has. Memcached is not and never hasn't been an alternative for APC, they are meant for two different jobs. I also agree that memcache is slower because it is out of process and that for some usecases the relative speed differences due to these context switches will impact application performance. Yes, they have different sweet-spots and operational characteristics, but for many usecases the relative impact will be immaterial, and memcached can be a perfectly acceptable substitute.

Applications which are closely coupled to high APC data cache usage will probably stay with APC for the foreseeable future. An SMA-based data cache would be a useful adjunct to O+, so I will be interested in this, but I just don't see this filling a show-stopper gap that must be addressed as a priority.

<snip> Laurence, you are correct that O+ doesn't provide data caching, but what about memcached and the PECL packages that support it? http://pecl.php.net/package/memcache and http://pecl.php.net/package/memcached