Cache strategies

How to use cache

1. Use cache with data that is read frequently but modified infrequently
2. Use persistent data stores in case cache server would be restarted
3. Expiration policy
4. Consistency. Sync cache and data store. Read more "Scaling Memcache at Facebook"
5. Mitigating failures.
6. Eviction Policy.
   1. Least-recently-used (LRU)
   2. Least Frequently Used (LFU)
   3. First in First Out (FIFO)