And oh yeah, add the HELL out of memory. Memory is fast, disk is sllloooow.
-- brion On Tue, Feb 18, 2014 at 2:40 PM, Brion Vibber <[email protected]> wrote: > A few thoughts: > > * If you're not already using memcached with a big RAM allocation as an > in-memory cache, I strongly recommend it. This will reduce churn on the > 'objectcache' table in MySQL for things like localization caches and the > parser cache (which may be churning a lot if you're seeing a large spike in > both visits and edits). > > * Consider separating MySQL out to its own VM for easier management or to > split up memory usage. Watch for high i/o usage and make sure indexes are > in memory... Beware that MediaWiki expects MySQL to be on the local network > and makes lots of roundtrips -- make sure if you use a separate VM to > locate it in the same DC at least. > > * Consider setting up a read-only slave database in another VM; depending > on your workload this may also help keep expensive lookups on the > secondary. It's also possible to route certain kinds of queries to a > particular database replica, which we use a lot on high-load Wikipedia > sites. This is a little tricky but not impossible. > > -- brion > > > > On Tue, Feb 18, 2014 at 2:11 PM, David Gerard <[email protected]> wrote: > >> rationalwiki.org is getting hammered again. It looks like MySQL is the >> busiest portion - seriously just doing a lot of work. >> >> Our current arrangement is: one box for MySQL, Apache, Lucene (the >> latter reindexing weekly); two Squids; a load balancer. These are all >> virtual machines on Linode (who we like). Apache and Squid boxes are >> Ubuntu 12.04 servers. >> >> The *usual* thing when we get hammered is that Reddit discovers an >> amusing tumbleweed article. The squids take care of this, of course. >> But then something like the Bill Nye/Ken Ham debate happens, we score >> pretty highly in Google for skeptical material and a wide variety of >> articles gets hit and MySQL has to work for a living. >> >> So, what's a good approach to scaling up MySQL on a VM? Add more >> memory? Add more cores? (How's MySQL 5.5-ubuntu do for multicore?) We >> can trivially add more Squids, and we haven't doubled up on Apache but >> shirley that won't be entirely unfeasible. >> >> >> - d. >> >> _______________________________________________ >> MediaWiki-l mailing list >> [email protected] >> https://lists.wikimedia.org/mailman/listinfo/mediawiki-l >> > > _______________________________________________ MediaWiki-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/mediawiki-l
