How to keep socket session opened when one of the web-server fails?

[MechSyQ]

In our system, our clients are connected to our web-servers via a load balancer. They open web-socket connection and authenticate against a single web server instance. It is very important for a connection to be super-fast. Now, if one of web-server is down, currently, our client should re-login to the system and connect to another web-server instance. We want to handle fail-over automatically without re-connection for our clients. How can we achieve that without breaking WebSocket connection? Can we do something on the load balancer level which will keep a connection with a client open and re-connect with a web-server instance? Do we have any other options?

[Martin Thompson]

Again is there a mechanical sympathy question in this?