Found one Java-level deadlock:
=============================
"TestDisconnectHandler-1":
  waiting to lock monitor 0x00007fdff40036f8 (object 0x00000007359182d0, a org.jgroups.protocols.pbcast.Merger),
  which is held by "jgroups-4,EntityCollectionInvalidationTest-NodeF-59512"
"jgroups-4,EntityCollectionInvalidationTest-NodeF-59512":
  waiting for ownable synchronizer 0x0000000735645138, (a java.util.concurrent.locks.ReentrantLock$NonfairSync),
  which is held by "TestDisconnectHandler-1"

Java stack information for the threads listed above:
===================================================
"TestDisconnectHandler-1":
	at org.jgroups.protocols.pbcast.Merger.cancelMerge(Merger.java:431)
	- waiting to lock <0x00000007359182d0> (a org.jgroups.protocols.pbcast.Merger)
	at org.jgroups.protocols.pbcast.CoordGmsImpl.init(CoordGmsImpl.java:34)
	at org.jgroups.protocols.pbcast.GMS.becomeCoordinator(GMS.java:407)
	at org.jgroups.protocols.pbcast.ParticipantGmsImpl.handleMembershipChange(ParticipantGmsImpl.java:114)
	at org.jgroups.protocols.pbcast.GMS.process(GMS.java:1296)
	at org.jgroups.protocols.pbcast.GMS$$Lambda$95/1582906120.accept(Unknown Source)
	at org.jgroups.protocols.pbcast.ViewHandler.process(ViewHandler.java:173)
	at org.jgroups.protocols.pbcast.ViewHandler.add(ViewHandler.java:111)
	at org.jgroups.protocols.pbcast.GMS.up(GMS.java:841)
	at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:233)
	at org.jgroups.stack.Protocol.up(Protocol.java:302)
	at org.jgroups.protocols.pbcast.NAKACK2.up(NAKACK2.java:591)
	at org.jgroups.stack.Protocol.up(Protocol.java:302)
	at org.jgroups.protocols.FD_SOCK.up(FD_SOCK.java:245)
	at org.infinispan.test.hibernate.cache.util.TestDisconnectHandler.lambda$down$0(TestDisconnectHandler.java:63)
	at org.infinispan.test.hibernate.cache.util.TestDisconnectHandler$$Lambda$392/1960261368.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
"jgroups-4,EntityCollectionInvalidationTest-NodeF-59512":
	at sun.misc.Unsafe.park(Native Method)
	- parking to wait for  <0x0000000735645138> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199)
	at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209)
	at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285)
	at org.jgroups.protocols.pbcast.ViewHandler.resume(ViewHandler.java:140)
	at org.jgroups.protocols.pbcast.Merger.cancelMerge(Merger.java:435)
	- locked <0x00000007359182d0> (a org.jgroups.protocols.pbcast.Merger)
	at org.jgroups.protocols.pbcast.CoordGmsImpl.init(CoordGmsImpl.java:34)
	at org.jgroups.protocols.pbcast.GMS.becomeCoordinator(GMS.java:407)
	at org.jgroups.protocols.pbcast.GMS.installView(GMS.java:688)
	- locked <0x0000000735918798> (a org.jgroups.Membership)
	- locked <0x0000000735643d68> (a org.jgroups.protocols.pbcast.GMS)
	at org.jgroups.protocols.pbcast.ParticipantGmsImpl.handleViewChange(ParticipantGmsImpl.java:135)
	at org.jgroups.protocols.pbcast.GMS.up(GMS.java:918)
	at org.jgroups.stack.Protocol.up(Protocol.java:336)
	at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:293)
	at org.jgroups.protocols.UNICAST3.up(UNICAST3.java:428)
	at org.jgroups.protocols.pbcast.NAKACK2.deliverBatch(NAKACK2.java:962)
	at org.jgroups.protocols.pbcast.NAKACK2.removeAndDeliver(NAKACK2.java:896)
	at org.jgroups.protocols.pbcast.NAKACK2.handleMessages(NAKACK2.java:870)
	at org.jgroups.protocols.pbcast.NAKACK2.up(NAKACK2.java:690)
	at org.jgroups.protocols.FD.up(FD.java:280)
	at org.jgroups.stack.Protocol.up(Protocol.java:344)
	at org.jgroups.stack.Protocol.up(Protocol.java:344)
	at org.jgroups.stack.Protocol.up(Protocol.java:344)
	at org.jgroups.protocols.TP.passBatchUp(TP.java:1255)
	at org.jgroups.util.MaxOneThreadPerSender$BatchHandlerLoop.passBatchUp(MaxOneThreadPerSender.java:284)
	at org.jgroups.util.SubmitToThreadPool$BatchHandler.run(SubmitToThreadPool.java:136)
	at org.jgroups.util.MaxOneThreadPerSender$BatchHandlerLoop.run(MaxOneThreadPerSender.java:273)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)