Memcache Knowledge Point Carding

http://369369.blog.51cto.com/319630/833234/

1, check whether the client's request data in the memcached, if any, directly return the request data, no longer do any operation on the database, the path operation is ①②③⑦.
2, if the requested data is not in memcached, go to the database, the data obtained from the database to the client, while the data cache a copy to the memcached (memcached client is not responsible, need the program explicitly implemented), the path operation is ①②④⑤⑦⑥.
3. Update the data in memcached every time the database is updated to ensure consistency.
4, when allocated to memcached memory space used up, will use the LRU (Least recently used, least recently used) policy plus expiration policy, the failure data is first replaced, and then replace the most recently unused data.

Memcache Knowledge Point Carding