With the release of WordPress 2.7 we’ve begun upgrading our customer sites to use this new version. As part of that effort, we needed to ensure that our hard won performance improvements were not adversely impacted. For the most part, this meant taking the time to review the PHP Speedy and WP Super Cache plugins to ensure they were still working as expected.
Leon Chevalier has released version 0.5.1 of his PHP Speedy WordPress Plugin. This version is compatible with WordPress 2.7, so we downloaded it and gave it a try. We had a couple issues with this version, but in the end I think we came out okay.
The first issue we encountered was an apparent compatibility problem with the All in One SEO Pack plugin. With the SEO plugin installed, PHP Speedy simply would not work. It took us a while to find this one, so if you’re reading this I hope it saves you some time. Disabling the SEO plugin allowed us to proceed.
The next issue we encountered was something related to enabling GZIP compression for the CSS file served by PHP Speedy. With our previous WordPress 2.6 installations we were able to successfully enable compression, but something’s amiss now. We haven’t (yet) gotten to the bottom of this one, but disabling CSS compression allowed us to continue testing other aspects of the plugin.
Which brings me to some fun news. The new version of PHP Speedy supports Data URIs, which provide a mechanism for embedding data items in a page. In particular, CSS background images can be converted automatically to Data URIs. Doing this increases the size of your CSS file, but decreases the number of unique files, and associated HTTP requests, for the page. You may be better off using the CSS Sprite technique I mentioned in a previous performance post, but you may also want to give this option a try.
Despite a couple small glitches, we were able to get PHP Speedy up and running with our WordPress 2.7 sites in fairly short order. This performance plugin continues to be an important tool in our WordPress performance kit.