Let's learn how Chubby implements its cache.

Chubby cache

In Chubby, caching plays an important role, as read requests greatly outnumber write requests. To reduce read traffic, Chubby clients cache file contents, node metadata, and information on open handles in a consistent, write-through cache in the client's memory. Because of this caching, Chubby must maintain consistency between a file and a cache as well as between the different replicas of the file. Chubby clients maintain their cache by a lease mechanism and flush the cache when the lease expires.