We all know that HTTP is the Web protocol, the protocol by which browsers and Web servers communicate. You’ve also almost certainly heard that HTTP is a stateless protocol. The rumors are true: HTTP maintains no state from request to request. HTTP is a simple request/response protocol. The client browser makes a request, the Web server responds to it, and the exchange is over. This means that if I issue an HTTP
GET to a Web server and then issue another HTTP
GET immediately after that, the HTTP protocol has no way of associating those two events together.
Many people think that so-called persistent connections overcome this and allow state to be maintained. Not true. Although the connection remains ...