True but not a problem. If you have 1,000 hits on a resource over a long time. Then, sure, it'll drop it and re-fetch from the origin when it needs. So, perhaps instead of just fetching it once, it might fetch it 10 times. That's rare enough that you need something performant on the origin. A web app is fast enough so not an excuse to use Nginx.
Hey,
this post makes obviously wrong assumption. CDNs take into account the HTTP headers (max age, etag etc) to determine the validity of a content. It does not mean that CDNs keep valid files forever in cache. CDNs usually run algorithms derived from LFU / LRU to determine which files they delete, when they decided to cache a new content and their disks are full. Your content will be in cache forever if it's indeed extremely popular. Otherwise, it will be deleted and potentially put again in cache later when some people request it again.
Cheers,
Gilles
Comment
True but not a problem. If you have 1,000 hits on a resource over a long time. Then, sure, it'll drop it and re-fetch from the origin when it needs. So, perhaps instead of just fetching it once, it might fetch it 10 times. That's rare enough that you need something performant on the origin. A web app is fast enough so not an excuse to use Nginx.
Parent comment
Hey, this post makes obviously wrong assumption. CDNs take into account the HTTP headers (max age, etag etc) to determine the validity of a content. It does not mean that CDNs keep valid files forever in cache. CDNs usually run algorithms derived from LFU / LRU to determine which files they delete, when they decided to cache a new content and their disks are full. Your content will be in cache forever if it's indeed extremely popular. Otherwise, it will be deleted and potentially put again in cache later when some people request it again. Cheers, Gilles