This class will coalesce increments from a thift server if
hbase.regionserver.thrift.coalesceIncrement is set to true. Turning this
config to true will cause the thrift server to queue increments into an
instance of this class. The thread pool associated with this class will drain
the coalesced increments as the thread is able. This can cause data loss if the
thrift server dies or is shut down before everything in the queue is drained.