Hi,
I have ongoing and heavy problems with my MediaWiki installation; it causes a continous high CPU load of 100% on a Dual Core AMD opteron (2 GB of RAM).
If I'm monitoring what's going on with "mytop", I find queries like, e.g.:
-- snip --
/* WhatLinksHerePage::showIndirectLinks 66.249.65.201 */ SELECT /*! STRAIGHT_JOIN */ page_id,page_namespace,page_title,page_is_redirect FROM `pagelinks`,`page` WHERE (page_id=pl_from) AND pl_namespace = '0' AND pl_title = 'Fungistatikum' ORDER BY pl_from LIMIT 51
-- or --
/* CategoryViewer::doCategoryQuery 217.227.171.13 */ SELECT page_title,page_namespace,page_len,page_is_redirect,cl_sortkey FROM `page`,`categorylinks` FORCE INDEX (cl_sortkey) WHERE (1 = 1) AND (cl_from = page_id) AND cl_to = 'Chemie' ORDER BY cl_sortkey LIMIT 201
-- snip --
66.249.65.201 and the other stressing acces are coming from a Google subnet, so I don't like the idea very much to block these hosts with ipchains.
However, these threads/processes run for hours and continue to increase the load, until the server becomes completey inaccessible (ssh doesn't respond any more) or MySQL simply dies.
I've tried so far (a) to mimic the setup of the Wikimedia wikis with a similar robots.txt, and (b) to enable file caching in MediaWiki; this might have halped a bit, but didn't solve the basic problem (i've to stop and restart mysqld every few hours).
Any help on this (or pointers to existing solutions) is greatly appreciated!
Greetings, asb