A cache store implementation which stores everything into memory in the
same process. If you‘re running multiple Ruby on Rails server processes (which is the case if
you‘re using mongrel_cluster or Phusion Passenger), then this means
that your Rails server process instances
won‘t be able to share cache data with each other. If your
application never performs manual cache item expiry (e.g. when you‘re
using generational cache keys), then using MemoryStore is ok. Otherwise, consider
carefully whether you should be using this cache store.
MemoryStore is not only able to store
strings, but also arbitrary Ruby objects.
MemoryStore is not thread-safe. Use SynchronizedMemoryStore instead if
you need thread-safety.