We have to change signature of startFlush method to include checked exceptions in its signature. We have previously relied on boolean return value of startFlush to get information about success of startFlush method invocation. This approach has been proven to be insufficient, particularly in the light of dealing with JGRP-985. We need to discriminate various reasons why startFlush failed, i.e due flush collision, missing response from flush member and so on. Therefore, starting with release 3.0 startFlush method will be void and will throw checked exceptions.