Session

A session typically includes a client machine and a server. It is implemented as a layer in network protocol such as FTP or telnet. In regard to transport protocol, sessions are maintained by a more advanced program. The program uses a method determined in the information being exchanged. For instance, the exchanging of HTTP from a browser and a remote server may include an HTTP cookie. This will identify variables such as the session ID, information concerning user preference and levels of authorization. Problems of consistency may occur when a client is able to connect to a cluster of servers. This is because the client must remain directed on one server for the duration of a session, or the servers must send server-side session data from a shared database or file system. If not, the client is subject to reconnecting to another server as opposed to the original. Issues may arise because the new sever will not contain all stored details like the previous one.