Before turning to unconventional methods of usage, I will describe how “keep-alive” is working. The process is utterly simple – in a connection, multiple requests are sent instead of just one, and multiple responses come from the server. The benefits are obvious: there is less time spent on establishing connection, less load on CPU and memory. The number of requests in a single connection is usually limited by settings of the server (in most cases, there are at least several dozen). The procedure for establishing a connection is universal.