And I think this is the main use case they were looking for. If you have a web app where each request is a separate process/call (not uncommon), and you don’t have a good shared global state, Redis is a great tool. It is an in-memory data structure store that can respond to requests from different processes. I always considered it an evolution from memcached.

If you only have one long lived process or good global variable control, then it is much less appealing in the single-server scenario. Similarly, if you require access from multiple hosts, it becomes a less obvious choice (especially if you already have a database in the loop). And redis is also overkill is you’re using it only as a cache.