I’m using Google App Engine to cache my static files for a while now. So far, i’m quite happy with my blog performance and using Google App Engine as CDN is definitely improve my blog page speed. I even upgrade to add more bandwidth, since i exceed the bandwidth quite often.
After using it quite sometimes, and i was have an issue with the cache. Google App Engine cache my static files to all the edge servers. So when i’m doing an update (in css file for example), it was still show the old file instead of the new updated file. It is still cached.
So how to trick this issue, so you can access the new updated file instead of old file? You can add version query string at the end of your file url.
Url without query string: http://cdn.ivankristianto.com/styles/min.css
Url with query string: http://cdn.ivankristianto.com/styles/min.css?v=1.0
So when i update my css file, i just need to increment the version, so i will get the new updated css file. It is a small trick to revalidate you cache files in Google App Engine, but help a lot when fixing my design.