After you enter the URL from the browser HTTP request to return the results of the complete process
1. FIG follows:
2. process analysis:
(1) After the jump browser, enter the URL the browser will first determine whether this link (URL) need redirection (Redirect), will need to jump to the redirect page, then you do not need to go to the next step.
(2). After determining whether to redirect the browser will determine whether there is a link to access this buffer (previously visited). There cache fetch data directly from the cache, the process proceeds to the next step without caching.
(3). After the first two steps done this time the browser will send a request to start the real, the first step is to send DNS requests, as we enter the URL of the domain name only, so the browser also need to use DNS to resolve domain names, parsing get the server IP address after completion of longer accessible.
(4) Create a link at this time needs to be 3-way handshake with the server, if the request is https, then because of security needs to be done, and it will create a different way of http.
(5) After the completion of the handshake starts transmitting real REQUEST request
(6). Server receives a request to make a corresponding process and then returns the response (data) response to the client
Summary:
1, the need for redirection;
2, if there is a cache;
3, the DNS name resolution;
4, addressing server;
5, to create a connection (3 way handshake) / HTTPS requiring special security mechanism;
6 sends REQUEST request;
7, and the server response to the client process;
