Description of problem: Currently, JGroups transport thread pools use discard as a rejection policy. Thus if there are no available threads, and the queue is full, the executor will silently drop the task. Abort will throw a RejectedExecutionException, in which case, which JGroups catches to populate the num_rejected_msgs statistic. This is a better default, so that users can monitor this value to determine whether or not to modify their thread pool configuration. Otherwise, num_rejected_msgs is 0, which might be a source of confusion. This has already been fixed upstream and documented in JGRP-1965(https://issues.jboss.org/browse/JGRP-1965). Discussing it with Paul Ferraro, we thought it would be quite relevant to backport in EAP 6. Version-Release number of selected component (if applicable): 3.6.6