A RemoteCacheManager instance is created for each test method in RemoteQueryDslConditionsTest, because of the @CleanupAfterMethod annotation. But the @AfterTest method that stops the remote cache is only once for the entire class, so all but one of the remote cache managers are not stopped properly.

GenericKeyedObjectPool registers a timer in EvictionTimer, which keeps the pool and the TcpTransport objects in it alive. And because the size of the buffer used by the transport is very big (1838kb on my system), RemoteQueryDslConditionsTest and its subclasses can quickly fill up the heap.