bennow

We have the same problem with the same queries. We have a site getting about 500k pageviews a day. We have it nailed down to having a large number of posts (60,000 total) in a single category (14,000). Any time you do a GROUP BY or ORDER BY, mysql has to create temp tables to do the sort operations. Since it’s a write-op, query caching has no affect. Plus any time you do an update to a post in that particular category, it invalidates cache, and forces users to an unprimed cache page, thus resulting in harder hit in the db load. We’re getting hit with 200+ concurrent users, each trying to hit that same query, which backs up in the db, and eventually crushes the server.

DB Cache will work if you’re on a single server, but if you’re on a multi-server, then you need something like memcached.

We still haven’t nailed down fix just yet, other than to take the 14000 posts down to 2000, so the queries aren’t hanging in mysql. If you are or have access to a DBA that can tune the buffers on MySQL, I’m sure you can alleviate this problem, but other than that, haven’t found an exact solution just yet to stop this particular query from killing you under heavy load.

Sent it yesterday within 2 minutes of this getting posted… I can try again if you’d like. We have some issues with emails being sent out from there, so it’s probably more a sever configuration issue than anything else. Is there any other way to get you the info you need?

done. Can’t provide ssh/ftp info just yet. If it comes to that, and you really need it, I can get you that information

Thanks for the help ! I tried the automatic upgrade option and it didn’t work. Said couldn’t de-activate the plugin, and upgrade failed. Does that mean I need to manually deactivate it ?

Also, we’re running WPMU, and have separate config files for each site. If the config files have changed, and I leave the old ones there, will upgrading the plugins replace those config files, or do I need to delete the old ones completely, go through the settings panel and allow W3 to recreate the config files?

Maybe this is the issue we’re running into…..

We’re using memcache for pagecaching with W3 Total Cache, with WP mu…. We have one set that gets about 15mm pageviews a month, and we’re trying to get it on the WP platform. When we start moving traffic over, we get a backup in the wp_options table of hundres of _transient_rewrite_rules records backing up… all of which are just duplicate records. IT eventually just hoses our database because on pagerequests that table grows to 10-15 megs.

We disabled memcache on pagecaching, and went with disk caching instead. Hopefully this solves the problem. If we roll back our files and make the changes in trac, would that solve the issue we’re experiencing?