If you change wt.server.codebase property(reverse proxy URL), enable RMI socket factory, point gateway map codebase & rpc endpoint to actual rmi hostname. you can use any reverse proxy server to achieve this. The load balancer in your case should be capable of converting/rewriting all the user requests to corresponding active application node pool. The reverse proxy should also be capable of adjusting the location, content-location and URI headers on HTTP redirect response.
Thanks
Binesh Kumar
Barry Wehmiller