About the keep-alive in HTTP

<span id="Label3"></p><p><p>I. About HTTP</p></p><p><p>first, HTTP is a hypertext transfer protocol, <span style="font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:25.2px;font-size:16px;background-color:rgb(255,255,255);">is a request-and-response mode-based, stateless, application-level protocol, often based on TCP connection mode, the main features are as Follows:</span></p></p> <ol class="list-paddingleft-2" style="list-style-type:decimal;"> <li><li><p><span style="font-size:16px;font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;background-color:rgb(255,255,255);">Support Client/server mode;</span></p></li></li> <li><li><p><span style="font-size:16px;font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;background-color:rgb(255,255,255);">Simple and fast: when a customer requests a service from the server, it simply transmits the request method and Path. The request method commonly has, POST. Each method specifies a different type of contact between the customer and the Server. Because the HTTP protocol is simple, the program size of the HTTP server is small, so the communication speed is fast;</span></p></li></li> <li><li><p><span style="font-size:16px;font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;background-color:rgb(255,255,255);">Flexible: HTTP allows the transfer of any type of data object. The type being transmitted is marked by content-type;</span></p></li></li> <li><li><p><strong><span style="font-size:16px;color:rgb(255,0,0);font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;background-color:rgb(255,255,255);">No connection</span></strong> <span style="font-size:16px;font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;background-color:rgb(255,255,255);">: The meaning of no connection is to limit the processing of only one request per Connection. When the server finishes processing the Customer's request and receives the Customer's answer, the connection is Disconnected. The transmission time can be saved by this method;</span></p></li></li> <li><li><p><span style="font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:25.2px;font-size:16px;background-color:rgb(255,255,255);"><strong><span style="font-size:16px;font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;color:rgb(255,0,0);background-color:rgb(255,255,255);">No status</span></strong> <span style="font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;background-color:rgb(255,255,255);">: The HTTP protocol is a stateless Protocol. Stateless means that the protocol has no memory capacity for transactional processing. A lack of state means that if the previous information is required for subsequent processing, it must be re-routed, which may cause the amount of data to be transferred per connection to Increase. On the other hand, it responds faster when the server does not need the previous Information. </span></span></p></li></li> </ol><p><p><span style="font-size:16px;font-family:Georgia, ‘Times New Roman‘, Times, sans-serif;line-height:23.4px;background-color:rgb(255,255,255);"></span></p></p>