[RFC|Accepted] Session Backend Abstraction

[naderman]

Motivation
High traffic websites can already make use of memcache for improved caching. However volatile session data is still handled by the database, occasionally causing load problems.

Proposal
First very complete test coverage of current session code should be achieved to be able to guarantee the continued correct functionality of the session mechanism, which is of critical importance to running a board. The session code should then be refactored to provide an abstraction of the storage mechanism used, to allow for faster backends like memcache to be implemented.

Tracker Ticket
http://tracker.phpbb.com/browse/PHPBB3-9731

Patch (Work in Progress)
https://github.com/phpbb/phpbb3/pull/1322

[nall]

Since taking down the one and only memcache server would destroy all sessions (presumably -- unless you're planning to just cache what's in the DB), will memcache clusters be supported?

[naderman]

Yes they will be, just like we currently support them for caching.

[nall]

Yes they will be, just like we currently support them for caching.

Hmm. In includes/acm/acm_memcache.php, I see:

Code: Select all

                $this->memcache = new Memcache;
                $this->memcache->connect(PHPBB_ACM_MEMCACHE_HOST, PHPBB_ACM_MEMCACHE_PORT);

I believe connect() only supports a single server model. In order to support clustering, this needs to be changed to $this->memcache->addServer (called once per server).

[igorw]

A patch was submitted to fix this, and it will be included in phpBB 3.0.8.

For reference: http://github.com/phpbb/phpbb3/compare/ ... 81018b0915