LiteSpeed MemCacheD

LSMCD is a high-performance, distributed memory object caching system, generic in nature, but originally intended for use in speeding up dynamic web applications by alleviating database load.

You can think of it as a short-term memory for your applications. LSMCD allows you to take memory from parts of your system where you have more than you need and make it accessible to areas where you have less than you need. LSMCD also allows you to make better use of your memory. With LSMCD, all of your servers will look into the same virtual pool of memory. This means that a given item is always stored and always retrieved from the same location in your entire web cluster.

Also, as the demand for your application grows to the point where you need to have more servers, it generally also grows in terms of the data that must be regularly accessed. A deployment strategy where these two aspects of your system scale together just makes sense. This property remains the same as the number of servers increases.

Of course, you aren't required to use your web server's memory for cache. Many LSMCD users have dedicated machines that are built to only be LSMCD servers.