https redirection when node fails

Allow me to rephrase. In a proxy environment you can assume that client and server will both establish layer 4 connections with the proxy (not each other). There are mechanisms to persist layer 4 connections on the client side should the BIG-IP fail over to its peer, but generally an application server couldn't or wouldn't do this, so a node failover will always initiate a new layer 4 connection between the proxy and the new node.

 

 

If you do not terminate the SSL (tunnel the SSL) between the client and server, then a node failure will generally cause the client to initiate a new SSL session with the new node. If you do terminate (and re-encrypt) the SSL and a node fails, the BIG-IP will silently establish a new SSL session to the next node without seriously impacting the client side connect/session.

 

 

Your original request, if I understood it, was to allow the next node to "pick up where the previous node left off" in the event of a failure. TCP isn't really an issue on the server side of the proxy, and unless you're doing something with SSL (tunneling and passing client certificates), then that's not really relevant either. What you have left is application layer behavior. In other words, if the application sets some form of "state" with the client, it's imperative that you understand how that works to know if it's possible to replicate that state on another server. It may be something as simple as a cookie that carries all of the state information (rare), or something as complex as SharePoint for example, that mixes cookies, state tables, and view state form fields.