Major Description
Every so often, we find ourselves trying to debug a problem that happens in HTable where we exhaust all our retries trying to contact the region server hosting the region we want to operate on. Oftentimes the last exception that comes out is something like WrongRegionException, which should just never be the case.
As a way to improve our debugging capabilities, when we decide to throw an exception out of ServerCallable, let's show not just the last exception but all the exceptions that caused all the retries in the first place. This will help us understand the sequence of events that led to us running out of retries.