Understanding CDN's

Question

I've been downloading jquery with:

<script src="//code.jquery.com/jquery-1.10.2.js"></script>

and for some reason, the link went bad. Not a problem as I changed the link to use Microsoft's hosted CDN. I'm wondering though if I should just download the files so to prevent this problem happening again in the future. Is there any reason not to?

Answer 1

Ultimately if you download the files to your own server then you will not experience the same issue again. But there are other considerations:

Plus points for CDNs

1. may be faster network and worldwide mirrors so potentially better user experience / performance for your site users;
2. if you link to the latest version, eg library-latest-min.js then you do not have to alter your source code to get latest bug-fixed version of library (see negative below).

Negative points

1. If the CDN goes offline your site breaks.
2. If the CDN has a network slowdown your users suffer.
3. If you link to the latest version, eg library-latest-min.js then you do not have to alter your source code to get latest big-fixed version of library but if 'latest' holds any breaking changes then your site breaks.