In OCP environment, the Gossip Router DNS name may resolve to multiple IPs. The TUNNEL protocol creates a different connection using each of those IPs however, the following code is not ready to handle that case, which can overlap messages in the same byte array, leading to corruption.

ByteArrayDataOutputStream out=getOutputStream(request.sender, request.serializedSize());
out.position(0);
request.writeTo(out);
route(request.group, request.addr, out.buffer(), 0, out.position());

Source code link: https://github.com/belaban/JGroups/blob/f655d9d340f5f3a0b620cf422a0736f7fb6ed160/src/org/jgroups/stack/GossipRouter.java#L352-L355

To debug, I put one print at the beginning and one at the end, printing the thread name and the ByteArrayDataOutputStream identity hash code. Got the following sequence of events where it shows 2 threads using the same ByteArrayDataOutputStream concurrently.

Thread Connection.Receiver [10.0.2.100:7900 - 10.0.2.100:59298]-4 start using 1488737374
Thread Connection.Receiver [10.0.2.100:7900 - 10.0.2.100:59284]-3 start using 1488737374
Thread Connection.Receiver [10.0.2.100:7900 - 10.0.2.100:59298]-4 stopped using 1488737374
Thread Connection.Receiver [10.0.2.100:7900 - 10.0.2.100:59284]-3 stopped using 1488737374
removed _ea0231e55bec-47524 (10.0.2.100:42052) from group xsite