Description of problem:
org.hornetq.core.server.impl.QueueImpl#getConsumers returns the actual Set of consumers, but if another thread modifies this collection while the caller loops through the Set then a ConcurrentModificationException will be thrown. This is possible particularly in management operations that work on the Set of consumers like org.hornetq.api.core.management.HornetQServerControl#closeConsumerConnectionsForAddress.
Version-Release number of selected component (if applicable):
Verified with 6.4.5.CP.CR1
Retroactively bulk-closing issues from released EAP 6.4 cumulative patches.