Vishal, I'm not sure I understand your solution can I confirm a few things:
When you Quiesce instanceA this leaves instanceB responding to client requests?
When you Deploy AppVersion2 you are deploying to a cluster which contains InstanceA & InstanceB? When you do the deploy what prevents glassfish from pushing the application update to InstanceB? I don't see anything in the admin UI to control this. I'm not running the glassfish load balancer is that required for this to work?
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