4.4.2 Cross port affinity
Cross port affinity is the sticky feature that has been expanded to cover multiple ports. For example, if a client request is first received on one port and the next request is received on another port, cross port affinity allows Dispatcher to send the client requests to the same server.
One example of this feature is a shopping cart application. The user browses the products and adds them to his shopping cart using port 80 (HTTP). When he is ready to place the order, he is redirected to a HTTPS (port 443) site, which will encrypt all communication between the browser and the server. Cross port affinity enables Dispatcher to forward this user's requests for both ports 80 and 443 to the same server.
In order to use this feature, the ports must:
- Share the same cluster address
- Share the same servers
- Have the same sticky time value (not zero)
- Have the same sticky mask value
More than one port can link to the same cross port. When subsequent connections come in from the same client on the same port or a shared port, the same server will be accessed.
Cross port affinity applies to the MAC and NAT/NAPT forwarding methods of the Dispatcher component.