I've got page loading time on this site -- for constructed pages1 -- down to near 1 second times. Most of this one second is coming from network and rendering delays, which I'll have to sort out later -- locally I can curl the page in 0.065 seconds!). As previously documented, I've already done the following:
- used mod_deflate to compress the data sent over the network (for example, on our main page right now this reduces the data sent from 128K to 20.6K)
- loaded static images and scripts from an offsite server
After a lot of mulling today, I've made another big improvement. Formerly, we used to load information about the user's session from a URI called '/:admin/status/'. This returned three pieces of critical information: the IHOST, the USERID, and the HOME. The IHOST is the installation host (semantic.blogmatrix.com), the USERID is the user you are logged in as (or the empty string), and HOME is set only if you serve your pages from a different URI than the default2.
This caused rendering to pause for .75 to 1.5 seconds depending on how well the network was responding. Effectively, the made the site feel really sluggish.
We now do the following: IHOST is just built into the templates; USERID and HOME are loaded into Cookies when the user is logged in. When these values are needed, instead of taking them out of Javascript variables, we call functions that pull them out of Cookies.
Instant speed.
1. We don't work under the same model as TypePad or Blogger. We only put a page together when we don't have it in cache. This could take several more seconds. Once a page is constructed, we'll always serve it from cache until the cache is invalidated (say, by a new post or comment being added).
2. For example, I serve my personal blog as http://blog.davidjanes.com even though deep down it's really http://davidjanes.semantic.blogmatrix.com!