Php implements session multi-domain name multi-server sharing session_id

First, a sessionid is generated during verification;

 

The code is as follows:	Copy code
<? Php Session_start (); $ SessionId = session_id (); // Obtain the sessionid.   // Send the session to the client ......... ?>

The client carries the sessionid variable to request data.

 

The code is as follows:	Copy code
<? Php   Session_id ('$ sessionid'); // note that this function includes parameters. Session_start (); // This function must be after session_id ()   ?>

We should be able to understand the problem of sharing sessions among multiple servers. When the number of users on a website is too large, a server cluster will be used, for example, a dedicated login server. After a user logs on to the server, the login server saves the user's login information session, while other accessed servers, such as the movie server does not have this session, so we need to share the session through a unique identifier.