I have combined all the css and js files. Css is temporarily hosted locally, whereas js is hosted in a cdn. I am on a shared server. Host: Stablehost. Very reliable, friendly and short ping response. The site is not completed yet. The server is in Texas, but I wanted to test its performance in Europe (Paris). I have a few questions regarding speed optimization,
(1) The time to first byte is always more than 1.5s. Is there a way to decrease it?
(2) Rackspacecloud allows only 72h max for file expiration. Is there a way to counter it?
(3) This [Use persistent connections (keep alive):] always fails for my domain name.
Not sure if you have been there yet there is a pretty good site with lots of performance tuning recommendations for Joomla: http://www.joomlaperformance.com/
The flow for a CMS basically goes:
Uninstall any modules or plugins that aren’t absolutely necessary
Enable page caching (some platforms support it natively, some with modules/plugins)
Work on the page template (combine css/js, image sprites, etc)
The first byte time can be improved by enabling server-side page caching (usually). The CMS systems are very chatty with their databases which tends to make for really slow first byte times.
For the rackspacecloud expiration, is that specific to how long the files stay in the cloud or is that a limitation they put on the expires header they pass to the customer? Usually that kind of constraint is specific to the edge caching and not a requirement on the actual headers that get sent to the customer.
For the persistent connections, you need to look at your htaccess or server config (if it is apache) and make sure there isn’t anything in there that would explicitly break it (MSIE rules that force http 1.0 are a common problem). If you’re on shared hosting you may have to reach out to their support if it isn’t something in your htaccess files.
The jQuery selectors not descended from an ID is sort of experimental for finding inefficient jQuery code but if you ARE using jQuery it is something you would look at if you were having performance problems, particularly with the CPU getting pegged and the browser locking up. It doesn’t look like you are having that kind of problem so I wouldn’t worry about it too much.
to 3rsaku :
your first question in the list "(1) The time to first byte is always more than 1.5s. Is there a way to decrease it? " points to missing caching on the Joomla installation. The best way is here to use page caching for maximal speed-up of server response. You can use JotCache solution (plugin and component) for Joomla 1.5 - see JotCache, by V.Kanich - Joomla Extension Directory
