I've never really understood it either. In my experience, in order for a cache to be a possible solution to a given problem at all, you must either: 1. Be cont

I've never really understood it either. In my experience, in order for a cache to be a possible solution to a given problem at all, you must either: 1. Be content with/resilient to the possibility of stale data. 2. Gatekeep all reads and writes (for some subset of the key space) through a single thread. That's basically it.