Test graceful termination of RPCAgent with asymmetric load (#27761)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27761
# Problem
`rpc_test` currently only has test cases that put equal amount of work on every worker node.
The problem is that even if the `RpcAgent::sync` is implemented as an empty method. There is no termination misbehavior detected.
# Solution
At least add one imbalanced-loaded test.
ghstack-source-id: 91785984
Differential Revision: D5361435
fbshipit-source-id: 92d1f7cad61b27cdeadc2825ceab6e88d5e4b459