I moved this blog to a new system, which has a more up-to-date versions of all the software. It still basically works, but is really slow, despite running on a faster computer. All of the other services running on the new computer show a performance improvement over the old computer, rather than a drop, so I expect there must be some incompatibility between WordPress and other software components.The front page and category pages are only somewhat slow, but bringing up the management dashboard and the write post pages takes so long that the HTTP connection usually times out. The logs on the server side don’t show anything unusual, and the system idle time is more than 99% while the browser is waiting for the page, so it’s clear that the server side isn’t stuck in a loop.
I tried deactivating all plugins and switching to the default theme, just in case the plugins or theme were causing the problem, but it didn’t help at all. I’m baffled.
The old system was running Fedora Core 3 (32-bit) with WordPress 2.0.1, PHP 4.3.11, Apache 2.0.53, and Mysql 3.23.58. The new system is running Fedora Core 5 (64-bit) with WordPress 2.0.2, PHP 5.1.2, Apache 2.2.0, and Mysql 5.0.18. There is a known incompatibility between the Markdown plugin and PHP 5.1, but I’m not using Markdown.
I’m not sure how to determine whether Mysql is the culprit, but I suppose I’ll look into that possibility next.