Too-biased – Tobias Luetke’s thoughts – Memcached
Memcached has long been the answer to most questions containing the word scale. There are some spectacular memcached installations out there. Facebook is said to run a 200 server with 3TB of memory solely for servicing memcached; Shopify, twitter, digg, Slashdot and just about every other public facing application depends on it. Facebook’s installation is said to deliver a 99% cache hit rate while servicing tens of thousands of requests a second.
There are many ways to use this elaborate hash table and many ways which are more trouble then they are worth. In our experience the key to use memcached effectively is to ask it for the exact thing you want, but i’m getting ahead of myself.