On 16/04/13 12:02, MZMcBride wrote: > Greg Grossmeier wrote: >> <quote name="Greg Grossmeier" date="2013-04-10" time="12:49:25 -0700"> >>> If all goes well with the testing, we should be able to switch over >>> fully by this coming Monday. >> >> All went well, we're now fully on Redis. >> >> You can rejoice now. > > Hi Greg. > > I looked at your original e-mail and this e-mail, but I'm still not sure > what Redis is or how it relates to the MediaWiki job queue.
Redis <http://redis.io/> is an in-memory key/value store, a bit like memcached except with more features. We've been using it as a memcached replacement for session storage since the eqiad switchover in January, because it has a replication feature which can be used to synchronise data between the two data centres. It allowed us to switch from Tampa to Ashburn without logging everyone out. It's designed more as a persistent store than a cache. Memcached still wins for simple unreliable object caching, so we're still using memcached for that. We previously stored the MW job queue in MySQL. This gave us lots of useful features, like replication and indexing for duplicate removal, but it has often been hard to manage the performance implications of the high insert rate. Among its many features, Redis embeds a Lua interpreter on the server side. The new Redis job queue class provides a rich feature set superior to the MySQL job queue, primarily by the use of several server-side Lua scripts which provide high-level job queue functions. -- Tim Starling _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l
