Memcached is a used free system for the storage in cache of data in the ram memory, so that it avoids that the user must accede to a space of external data storage. Thus, the access to these data is very many faster.
At the moment, more and more servers VPS incorporate Memcached, in addition to other systems of cache. This system was developed in the middle of year 2003 of the hand of Brad Fitzpatrick, who implemented it in its LiveJournal website.
The operation of Memcached is based on a table hash, which is distributed in several equipment. This way, as this is arriving at its limit of storage, those data that are not used for more time erase for being able to store the new ones. Thus, one secures some extraordinary results of load.
The operation of this system is relatively simple to understand. The first a to consider is that Memcached goes to host and port specific, so that is able to store data in any type of format.
Then, the main task of Memcached is to store the items, the assigned word to denominate to the data, in a great table of hash that is distributed in two or more equipment. The system is in charge to mapear the items based on the key that the user has assigned to him to each of them, which cannot have a weight greater to 1 Megabyte.
One of the characteristics of Memcached is that burglaryable is a system with architecture. This way, if at a certain moment the amount of connections is greater to the one than it can support an only servant, it distributes the load with other servers.
The Memcached protocol only implements three commandos of storage that is worth the trouble to consider.
The users use bookstores to accede to the servers, so that all of them have a detailed list of all the servers. However, the servers do not communicate among them.
At the moment, Memcached is a system more and more used by some of the most popular websites worldwide, among them several social networks as YouTube, Facebook or Twitter. It is necessary to consider that the traffic in this type of websites is more and more massive, so that the companies have been forced to bet by Memcached to increase the speed of answer to requests Web of the users.