Hi, Stumbled on the fact that LocalDirAllocator.ifExists() is not used anywhere. The previous usage of this API was in the IsolationRunner that was removed in MAPREDUCE-2606.
This API doesn't call the confChanged method and hence there is an uninitialised variable that causes a NullPointerException. So, either we can fix that, or remove the API if it's not required. This is also one of the reasons why the IsolationRunner was broken in 1.0. Thoughts ? Thanks hemanth
