Hi all, I have a slight issue with my setup, and am in need of advice.

I run a small Roku video channel, and am looking for a new CDN capable of caching my content for about 5 days at a time.

Basically, all my video files are hosted on an S3 instance, which pass through a CDN before going on to my Roku clients.

In theory, a CDN should grab a requested file from the S3 instance one time, and serve it up to all the viewers requesting it, correct? So for example, if on Monday I have 100 clients watching "War of the Monsters (1966)", the CDN should just request that file from S3 once, and serve it to the 100 viewers.

In practice, my CDN is requesting the file from S3 100 times, once for each viewer. It isn't actually doing any caching at all.

I've been talking with the CDN's tech support and they claim "everything is working fine," but the logs (and bills) from Amazon say differently.

So am I wrong here, or is my CDN costing me more money for zero benefit?

UPDATE: The CDN has asked me to change a metadata tag on the S3 instance, adding "Expires: max-age=15811200" to ALL my files. I'm doing it, but will it actually help?

UPDATE 2: Apparently it's fixed! We're at 89% cache hit ratio after 9 hours. Of course, I'll be monitoring that moving forward. Thanks to everyone for the help!