Are you looking to improve the performance of you WordPress website running on Azure websites service? If yes, then what you need a cache to help speed up your website. If you website gets heavy traffic, it is optimum to set up some form of distributed memory caching mechanism.
Memcached is a general purpose distributed memory caching system. It is often used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an external data source (such as a database or API) must be read. Memcached system uses a client–server architecture. The Client which would be your website will use client-side libraries, in this case PECL memcached library to contact the servers which expose their service at port 11211. Each client knows all servers; the servers do not communicate with each other.
If a client wishes to set or read the value corresponding to a certain key, the client’s library first computes a hash of the key to determine the server to use. Then it contacts that server. The server will compute a second hash of the key to determine where to store or read the corresponding value.
Memcached Client must treat memcached server as a transitory cache; they cannot assume that data stored in Memcached is still there when they need it. MemcacheDB, Couchbase Server,
Varnish and other database servers provide persistent storage while maintaining Memcached protocol compatibility.