Method to purge cache

[louisgcom]

Hello,

I noticed that vumbnail.com caches video thumbnails using Cloudflare and Vercel with the following cache policy:

'Cache-Control': public, max-age=${ ONE_MONTH }, s-maxage=${ ONE_YEAR }

This means that thumbnails are stored for one year on Cloudflare's cache, making it impossible to refresh them if a new video thumbnail is updated.

Problem

• Adding query parameters (e.g., ?timestamp=12345) does not bypass the cache.
• Sending Cache-Control: no-cache or Pragma: no-cache headers from the client has no effect.
• Cloudflare ignores Range requests as well.

The only way to get a fresh thumbnail is to wait for the cache expiration or manually purge it (which is not possible for users).

Example:

• Old thumbnail: https://vumbnail.com/919072679.jpg
• New thumbnail: https://vumbnail.com/919072679_default.jpg

Suggested Solutions

Would it be possible to implement a method to force a cache refresh? Here are some potential solutions:

• Support cache-busting query parameters (e.g., https://vumbnail.com/919072679.jpg?v=timestamp) to serve fresh thumbnails when needed.
• Reduce the Cloudflare/Vercel cache duration (s-maxage) to a more reasonable time (e.g., a few days).
• Provide an endpoint to purge an image from the cache when necessary.
• This would be very helpful for users who frequently update video thumbnails on Vimeo.

Thanks for your work on vumbnail! Looking forward to your feedback.

Best, Louis

[ThatGuySam]

That makes sense why people are having so much trouble cache busting.

The tricky part is that the app is serving almost 100m thumbnails a month now so I definitely want to be careful not to mess up the cache and get a huge bill.

I've thought about a query string but it's a bit of boy scouts honor that it won't be used all the time/in prod. Maybe, I could just enable it until someone abuses it too much.

I've thought about setting up a dedicated page with a captcha connected to the Cache API for flushing thumbnails one at a time.

Another option could just be setting up paid accounts with better cache controls so that people can serve as fast as their hearts desire.