Multiple CSS, JS and images URL's

In general, anything with more then 4 aliases starts to hurt performance; with parallel you are using 3. I could add in 1 more alias for images, but that would be it. Server selection: add all the ascii values of the filename together and if thats even, serve from one server, odd the other.

$count = 0;
foreach(str_split($filename) as $char) {
  $count += ord($char);
}
if ($count%2) {
  // assign to sub domain A
}
else {
  // assign to sub domain B
}

Might need to use a UTF-8 compatible version of the ord() function.
http://php.net/ord#78032

css helps; all css images then get downloaded from the separate domain

Hi,

Here's a patch to add multiple domains for images. New variables are used in case people use the old one for something else too, e.g. patching lightbox. And the regex has to be changed because we need to look at the filename too.

fixed some white space issues and changed the global variables into static ones since they are only used inside the new function. Let me know.

indeed, statics variables are better.

#5 works great! I noticed that fastest load times if I only put in three domains for the new IMG field, and I leave all the original CSS, JS and IMG fields blank.

Doing this cut an additional .5sec from my page load time.

Check it in action: http://www.ivawbeta.org/

Web Page Speed Test Results: http://www.webpagetest.org/result/100828_3QZG/1/details/

I'm coming in late to the game here, but as an alternative approach you could switch based on path instead. For example on one of my sites about half of the img tags are imagecache files. By switching based on path you have the benefit of being able to build matching rules in .htaccess if you are hyper-SEO concerned (I'm not but enough of the people in this issue queue are).

I can think of three groups for images:
- imagecache
- in the files dir but not imagecache
- other

This has been supported by the CDN module for a long time now. As per #933942: Merge Parallel and CDN modules: migration path, the Parallel module will be merged into the CDN module, so if you migrate now, that won't be an issue anymore :)

Note that you can also write your own logic in the CDN module, to decide which domain should be used.