In-Memory (Redis)

• In-memory store

• Fast (because it uses memory instead of disk)

• Usually it is not used as the main datastore

While it is usually used for cache, but you can also use it for other stuff such as distributed locking (redlock).

To read more about redlock:

• https://redis.io/docs/manual/patterns/distributed-locks/

• https://dev.to/lazypro/explain-redlock-in-depth-31jj

(more about distributed lock later)