Impact of Google Api Librarys

Support
1

With all of the CDN sources that can be used to assemble a webpage, the webpage page load times are becoming more complicated.

My webhost has added 79k of jquery libraries from a google CDN that load on every webpage without an option to turn them off. (library files detailed at bottom of post).

They insist that most visitors to my site will likely have been to some other site that has already cause these files to be on their local cache, thus only impacting page bytes and load time by 79k on the first site view if a visitor has never been to another site that uses these libraries.

Even if they are not accurate about a visitor having these files loaded from some other site, it is true that the second page and beyond on our site would already have these libraries cached.

So during a visitor’s session, page speed will be different as they move between pages because of the previously loaded libraries. As a result load times may actually be faster than WebPageTest is reflecting on a “First View” of a page if the visitor arrived from another page on the same site.

As a result we have 3 different views that we need to consider for any page:
– First Site View, first page view
----- Global Libraries not yet cached
----- Page specific local files not yet cached

– Repeat Site View, first page view
----- Global Libraries already cached from first site view
----- Page specific local files not yet cached

– Repeat Site View, repeat page view
----- Global Libraries already cached from first site view
----- Page specific already cached from first page view

Presently webpagetest shows both “First Site View, first page view” and “Repeat Site View, repeat page view” but I am not sure how to determine “Repeat Site View, first page view”

Is there a way to run webpagetest as a “Repeat Site View, first page view” that would considers global library files to already be loaded?

Thanks.
Tim.

Google Libararies Mentioned:
49k http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/jquery-ui.min.js
24k http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js
6k http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/base/jquery-ui.css

2

In “Advanced Settings” you can block request containing “http://ajax.googleapis.com” in order to simulate an already cached library.

3

Be careful blocking it, that will break any functionality on your page that depends on it.

The best way would be to use a script and have a dummy page that just serves the content you want to be cached. First navigate to the dummy page and then navigate to the page you want to measure.

Thanks,

-Pat