Hello, Aparna
I'm glad that someone has a similar problem with me.
I cannot find any solution to solve this problem in JBoss yet.
When the backup server becomes live, it will not redeploy its applications.
This means the status of the deployment is still failed.
Now, I write a shell script on the backup server.
It will check whether the live server is alive every one minute,if the live server is dead, kill the status file(rm /~/*.failed), then it will redeploy...
(I know it's not a good method. :p )
but I still want to find how to solve this problem by JBoss, or maybe it really did not support this feature.