[eli]

You don't need to rename the files. As of a few months ago, you can configure CloudFront to take query strings into account when caching, so you can simply link to the file as normal but append "?<your_hash_here>" to the filename. (I actually prefer using the last modified timestamp over a hash.) IMHO, this is better because it requires less magic on the origin server. And even ancient references to a file (a logo someone hotlinked, for example) will still render rather than 404, so long as the name hasn't changed. No need to keep tons of old revisions of files around.

[autoref]

This isn't recommended since many browsers and proxies do not cache resources that are referenced using a query string, even if a cache-control or expires header is set appropriately. Google says Squid up to 3.0 will not do so:

https://developers.google.com/speed/docs/best-practices/cach...

[eli]

Fair point and thanks for the link -- I've only seen this phrased as a warning against "some proxies" that I've never personally encountered. But I can live with it. If your proxy is broken in this way, you will have to fetch the asset from the CDN rather than benefit from your local proxy.

[latchkey]

Squid 3.0 was released in 2007. It can be argued that this is an out of date recommendation. My experience using query strings has been fine.

[eli]

To be fair, I think it was still the current version up through 2011.

The more important point is that the failure mode is simply that the assets load from the CDN as if there were no squid proxy. This is not ideal, but it's not so bad either.

[ludwigvan]

Another reason this is not recommended is that, if you rename the files, you can send them to the server and then reload your app.

If you don't, there might be a small amount of time before your app is reloaded where your app uses newer resources.