The current implementation of HRegionServer#stop is
The notification is sent on the wrong object and does nothing. As a consequence, the region server continues to sleep instead of waking up and stopping immediately. A correct implementation is:
Then the region server stops immediately. This makes the region server stops 0,5s faster on average, which is quite useful for unit tests.
However, with this fix, TestRegionServerCoprocessorExceptionWithAbort does not work.
It likely because the code does no expect the region server to stop that fast. See