WordPress memory usage spike


I run 15 separate installations of WordPress 3.0.1. On Sep. 9, my memory usage more than tripled and has stayed there ever since. Observe:


I thought this issue might be a consequence of a plugin or two that I updated, but I’ve tried downgrading each plugin in turn and have seen no resultant decrease in memory usage. Rebooting the server has also had no effect on this resource.

Is there a good way to diagnose what’s causing this memory surge, or does anyone have any suggestions of what I might do to resolve it?

I pretty much have the same trouble. Things got so bad, I switched to Nginx. It was good for a couple of days but memory spikes are now happening all over again.

Check your wp-options table in phpMyAdmin to see if there is any “overhead” there (it shows in red text), and if there is, then “optimze” that table to remove it.

This is common with WordPress and plugins, and may well be the source of your trouble.

Thanks, rlparker! I was unfamiliar with this operation. I conducted it via phpMyAdmin, then moved to Navicat once I figured out where that command was.

Unfortunately, my sites’ memory usage in the 21.5 hours since optimizing the tables of all 15 MySQL databases has not changed.

I’m now looking at my access logs to see if there’s any heavy traffic I can better manage with robots.txt.


By editing my FastCGI settings and robots.txt files, and by deleting some plugins, I got my memory usage down from 349 MB to 245 MB. This is below the 300 MB minimum memory setting for a PS, but still well above the 60 MB of activity I used to see.

The WP Tuner plugin doesn’t detect anything slow or otherwise unusual on several of my sites.