HotRod client test suite hangs in ClientConnectionPoolingTest.tearDown

Sometimes the HotRod client test suite hangs at the end.
Almost all of the live threads are client worker threads or server threads, the only test method running after a while is ClientConnectionPoolingTest.tearDown:

java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)

• parking to wait for <0x765e2148> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
  at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:226)
  at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2081)
  at java.util.concurrent.ThreadPoolExecutor.awaitTermination(ThreadPoolExecutor.java:1425)
  at org.jboss.netty.util.internal.ExecutorUtil.terminate(ExecutorUtil.java:87)
  at org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory.releaseExternalResources(NioServerSocketChannelFactory.java:146)
  at org.infinispan.server.core.transport.netty.NettyTransport.stop(NettyTransport.scala:117)
  at org.infinispan.server.core.AbstractProtocolServer.stop(AbstractProtocolServer.scala:96)
  at org.infinispan.server.hotrod.HotRodServer.stop(HotRodServer.scala:169)
  at org.infinispan.client.hotrod.ClientConnectionPoolingTest.tearDown(ClientConnectionPoolingTest.java:103)