4.7.2.11. Session persistence in load balancing

Zorp’s HTTP proxy offers the ‘session persistence in load balancing’ feature, further enhancing Zorp’s load balancing capabilities by that.

With the help of this feature, the Round Robin chainer can identify connections by their session IDs and make sure that every connection with the same session ID is always addressed to the same server, so that the session persists.

For using the ‘session persistence in load balancing’ feature, the administrator has to configure the following three attributes for the HTTP proxy:

  • Enable_session_persistence

    You can switch on or off the ‘Session persistence in load balancing’ feature with that parameter.

  • Session_persistence_cookie_name

    This parameter can only be configured if enable_session_persistence is set to TRUE. The administrator can provide the name of the cookie here: Zorp directs all incoming requests to a web server and each web server sends a session ID back to Zorp. The name of this session ID, that is, the cookie name, can be provided here to ensure that requests with the same session ID are directed to the same web server.

  • Session_persistence_cookie_salt

    This parameter can only be configured if enable_session_persistence is set to TRUE. The administrator can provide the salt here, with which the IP address of the web server can be hashed before the session ID. With the help of this hashed information Zorp can next time identify to which server the next connection attempt of this session has to be directed.