By sp_key on

Hi all,
I recently installed Google's Page speed performance analysis tool in firebug and after analysing my website I got the below message:

"This page makes 33 parallelizable requests to example.com. Increase download parallelization by distributing these requests across multiple hostnames:"

The explenation takes me to Google's help site at http://code.google.com/speed/page-speed/docs/rtt.html#ParallelizeDownloads but still after reading it I'm not entirely clear about what I need to do.

I am hoping someone can advice me using a simpler language :)

Many thanks!
Sp

⋅ Categories: Drupal 6.x

Comments

sovarn’s picture

sovarn commented

Basically every single call to the server is a request.
It means you have 33 objects on the page be they images, css files and javascript files.

I'm guessing it is the latter two. The more modules you add the more css and js files there will be.
Just go to site config -> perfomance and enable the optimise CSS + JS option.

Try this and see what page speed says.

If it is a bunch of images then try using css sprites for repeated images (icons/logo etc) so it only makes one request.

However dont worry too much about this, if the page loads fast then it should be fine.

sp_key’s picture

sp_key commented

Hi, thanks for your response.

This is already with css optimization running (can't have js optimization due to a module incompatibility with it).

The page seems to load fine for me and browsermob (http://browsermob.com/performance-testing) seems to find no error with it either. It's google webmaster tools that finds it slower than 99% of the rest of the sites (under performance) that worries me.

css sprites?

Many thanks again
Sp.

lightbody’s picture

lightbody commented

I think what the report is saying is that if you were to alias your hosts (all to the same IP), you could achieve better parallelization. For example, suppose your site downloads these files:

www.example.com/css/main.css
www.example.com/css/theme.css
www.example.com/css/forms.css
www.example.com/css/widgets.css
www.example.com/js/main.js
www.example.com/js/ajax.js
www.example.com/js/jquery.js
www.example.com/js/utils.js

Older browsers (pre IE8/FF3/Safari 3) will download no more than two connections per host. So that means those 8 objects would get downloaded in 4X time. Modern browsers do 8 or more concurrent downloads per host (FF3.5 upped it all the way to 16!) so the report is bringing up something that is less of an issue these days.

However, you could in theory speed up the site for all browsers by making www1, www2, www3, and www4 aliases to the same site and then downloading these files:

www1.example.com/css/main.css
www2.example.com/css/theme.css
www3.example.com/css/forms.css
www4.example.com/css/widgets.css
www1.example.com/js/main.js
www2.example.com/js/ajax.js
www3.example.com/js/jquery.js
www4.example.com/js/utils.js

Of course, the effort to do that (and configure your Drupal plugins to request the files from those other hosts) is pretty large, so my recommendation would be: if the site is fast for you, don't worry about it. Of course, if you can compress/concat the CSS and JS code to a single file, that would be the best thing to do.

Btw, I'm the founder of BrowserMob and I'm glad you like the service. Feel free to email us with any feature requests or ideas. Thanks!

Patrick Lightbody
patrick@browsermob.com

sp_key’s picture

sp_key commented

Great!
Many thanks for your post - I fully understand now and indeed I have a few ideas I'll email you about soon :)

alexbk66-’s picture

alexbk66- commented

If you have good ideas, share them here, not email.