AlloyUI and the importance of CDN

Some weeks ago we announced the preview release of AlloyUI 2.0. One of the cool things about it is that now we have a pretty new CDN (Content Delivery Network). So instead of downloading AlloyUI to use in your local environment, you just to need copy and paste this line of code and start using it.

	<script src="http://cdn.alloyui.com/2.0.0pr2/aui/aui-min.js"></script>

But it was only available for AlloyUI 2.0, which is not integrated with Liferay yet, then Liferay community wouldn't benefit from it.

That's why today we have some news to share, all versions of AlloyUI are now available on CDN to use in production or to download as a zip file \o/

PS: Check this table if you don't know which version is being used by Liferay.

Why it's so important to use a file hosted on a CDN?

Basically for performance improvements, we'll dig into some of them.

Decrease latency

Let's say you are in China and your server is in Los Angeles. When you load a file the browsers sends a HTTP request that will go across the globe until reach your server and, as you can see, it takes time.

However if this file is hosted on a CDN it will be distributed across many different servers in the world. So when you make a request, it will look for the nearest server, which decreases latency time a lot.

Wikipedia: (Left) Traditional scheme of distribution - (Right) CDN scheme of distribution

More parallel downloads

Browsers can't handle too many parallel downloads per domain.

That's why hosting files in different domains is a good performance tip.

Cache

Let's say you visited a website that uses AlloyUI hosted on CDN, as soon as you load it your browser will automatically cache it in your machine. Then if you visit another website that uses AlloyUI too, you don't need to download all those files again because you already have cached them.