Sharing session cookies on multiple servers session start sessionfactory session failed

ini_set('session.cookie_path', '/');
ini_set('session.cookie_domain', '.test.com');
ini_set('session.cookie_lifetime', '1800');
if($_SERVER['HTTP_HOST']=='test.com'){
header('HTTP/1.1 301 Moved Permanently');
header("Location: http://www.test.com/");
exit;
}

The above introduces the sharing of session cookies under multiple servers, including the content of Session and cookies. I hope it will be helpful to friends who are interested in PHP tutorials.