About caching system at Facebook.
Facebook has two major cache systems: Memcache, which is a simple
lookaside cache with most of its smarts in the client, and TAO, a
caching graph database that does its own queries to MySQL.
The NSDI’13 paper introduces more about Memcache: https://www.usenix.org/conference/nsdi13/scaling-memcache-facebook
The USENIX ATC’13 paper introduces more about TAO: https://www.usenix.org/conference/atc13/tao-facebook’s-distributed-data-store-social-graph