Move Redis Session State Store to an separate Redis instance
Spun out of https://docs.google.com/document/d/1vKcT_PcX6qDHeWTA-e4we9eambKQPq6SGHnRLYN_1GM/edit
Redis Session State is distinct from much of the other state stored on our persistent redis instance.
Additionally, the client it uses is:
- a third-party component, maintained by Redis (https://github.com/redis-store/redis-rails)
- not Redis-Cluster friendly (CROSS-SLOT mgets)
Moving this over to its own specialised Redis connection which could (in the case of self-managed instances) be the same instance as Redis Persistent would:
- Give us more runway before saturation of our persistent Redis
- Allow us, in future, to more easily consider moving over to Redis Cluster for much of the Persistent Redis workload.
cc @grzesiek
Edited by Sean McGivern