: What's the best way to version CSS and JS URLs? As per Yahoo's much-ballyhooed Best Practices for Speeding Up Your Site, we serve up static content from a CDN using far-future cache expiration

@XinRu657

According to Google's Make the Web Faster, pages with query parameters are not cached by many HTTP proxies.


Most proxies, most notably Squid up through version 3.0, do not cache resources with a "?" in their URL even if a Cache-control: public header is present in the response. To enable proxy caching for these resources, remove query strings from references to static resources, and instead encode the parameters into the file names themselves.


So styles.min.abcd1234.css is the preferred solution. You can use an appropriate URL rewriting mechanism to turn styles.min.abcd1234.css into the easier to implement styles.min.css?v=abcd1234 transparently.

If you support HTTPS only, that advice does not apply, because proxies can't normally cache pages that are served over SSL.

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@YK1175434

this is not an answer to the above question, I want a better solution so I am asking here itself

Both of the methods would require modification to the files where the css and js files are referred. So in effect it would require a restart of the application server after making the changes.

Is there a better way, where versioning of static files can be handled without having to restart the Application server ?

the following is ruled out in the solution


changing the css and js filenames
passing a query paremeter in the url


the solution also should not affect setting cache-control or expires.

thanks

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@Yeniel560

Using the GET-style versioning, from a blank cache multiple URLs - e.g. style.css?v=123 and style.css?v=456 - would return the same content. However I can't see this would be problematic, especially since you'd only link to one at a time.

I think you'll find the GET-style much easier to maintain. You don't need separate files: just change the URL and browsers will fetch the CSS afresh.

UPDATE: on further research it appears that using a query string may stop browsers caching the files. However, if you are returning proper headers such as Expires this is not an issue.

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@Kevin317

Both will work equally well as a query string is considered part of the URL and by changing it you are in effect changing the name of the resource thus causing the browser to fetch a new copy of the file.

I say use whichever method is easier for you to maintain.

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