I\'m building a system that tracks and verifies ad impressions and clicks. This means that there are a lot of insert commands (about 90/second average, peaking at 250) and some
If you have the choice (and need to move away from flat fies) I would go with Redis. Its blazingly fast, will comfortably handle the load you're talking about, but more importantly you won't have to manage the flushing/IO code. I understand its pretty straight forward but less code to manage is better than more.
You will also get horizontal scaling options with Redis that you may not get with file based caching.