[dustym]

Great point. I don't speak for the guys that made the decision to append the timestamp to the query, but I assume our concern is in intermediate network caches that don't honor low TTLs. Though I don't know how founded that is, we won't ever have to deal with the issue if we take control of it with the url string.

It'd be interesting to see how wide the key space is due to clock skew. I suppose we could specify some number and consider it a global counter that is incremented every second, then when someone comes in for the first time they can by synced in with the global incrementing counter. That counter is used to ensure a fresh cloudfront hit.

I think at end of the day, these issues haven't been a huge concern for a one month emergency project, but they are good points.