Re: Memcache session handler

The CVS version of pecl/memcache now has session support, you may check out and build a copy as cvs -d :pserver:cvsread@cvs.php.net:/repository checkout pecl/memcache cd pecl/memcache phpize ./configure make make install The session save handler is activated from INI as session.save_handler = memcache session.save_path = "tcp://host1:11211?persistent=1&weight=2,tcp://host2:11211" The parameters accepted on the url are "persistent", "weight", "timeout" and "retry_interval" (same as to Memcache::addServer().) You may add any number of servers separated by commas. The new unix domain socket feature may also be used as "unix:///path/to/memcache.sock:0" Feedback and help with testing would be most appreciated. //Mikael Glenn Richmond wrote: > Hi Mickael & Antony, > > I've attached the key session handling code for the memcache handler. It > uses libmemcache as the back end, so naturally the function calls will > be slightly different when adding to the memcache extension. At the > moment, I configure the system in the php.ini with the following settings: > > session.save_handler="memcache" > session.memcache_server_1="xxx:xxx:xxx:xxx:11211" > session.memcache_server_2="xxx:xxx:xxx:xxx:11211" > > At the moment, the first server is compulsory, but the second is > optional. I integrated it directly with the standard files and user > session handlers initially just to test the theory, but we should be > able to separate now i think. Let me know what your thoughts are - > whether you want me to have a go at integrating it or if you want to > take the existing code and just port it. > > Best Regards, > > Glenn Richmond. > > Mikael Johansson wrote: >> I agree with Antony, there shouldn't be a problem integrating session >> handling into pecl/memcache. Some questions though >> >> * The extension needs to know the address of the servers in order to >> connect, so how do you start the session? >> >> 1) From php.ini using something like >> >> memcache.session_storage = >> "tcp://node01.example.com:11211?weight=2,tcp://node02.example.com:11211" >> session.save_handler = memcache >> >> 2) From your script as >> >> $memcache = new Memcache(); >> $memcache->addServer(...); >> $memcache->registerSessionHandler(); >> session_start(); >> >> * Memcache (as with any other cache) is inherently unreliable and might >> garbage collect keys in a LRU fashion should it need the memory for >> other keys. One might be able to mitigate this issue by ensuring that >> memcache has plenty memory, but until there's a (per key) DO_NOT_GC flag >> implemented in memcached there's always the risk of sessions being dropped. >> >> Better to have a 2-tier session storage where writes are passed through >> to a database (shared by all the web front ends) and reads are handled >> by the cache. For example: >> >> >> http://svn.synd.info/synd/trunk/core/lib/SessionHandler.class.inc >> >> But if you need the performance of storing the session only in memcached >> and are aware of the potential problems, you should be able to do so. >> >> If you wouldn't mind posting a link to your code and a patch against the >> current CVS head we'll try and integrate it as soon as possible. >> >> //Mikael >> >> Glenn Richmond wrote: [snip]