Among the many features provided by Macromedia's Web server clustering solution, ClusterCATS provides a feature called session-awareness. Session-awareness ensures that when a session begins on a particular clustered Web server, it will remain on that server until it is complete.

Nowadays, cookies have become almost as commonplace on the Web as images or tables. And they do all kinds of stuff: They help Web designers manage user information (by storing it between site visits) and decrease the amount of overhead necessary to keep track of user information, like usernames, encrypted passwords, form variables, and shopping cart information. And they also make things easier on users by eliminating the need to log on to a site every time they visit, or making it easy to personalize content on sites. (One man's trash is another man's treasure, and now neither of them need see the other one's useless drivel.)

Most Web sites accomplish this stunning feat with HTTP cookies. A cookie is a small piece of information that's sent to your browser - along with an HTML page - when you access a particular site. When a cookie arrives, your browser generally saves this information to your hard drive; when you return to that site, some of the stored information will be sent back to the Web server, along with your new request.