When trying to set up a domain configuration as explained in https://docs.jboss.org/author/display/WFLY9/WildFly+9+Cluster+Howto, I got lot of discarded messages both in MASTER and SLAVE servers.
I believe this is the reason why the SLAVE instances are not reflected in the admin console of MASTER.
[Server:server-three] 11:35:23,981 WARNING [org.jgroups.protocols.UDP]
(OOB-18,ee,master:server-three) JGRP000010: packet from 10.81.169.177:45688 has different version (3.2.7) than ours (3.6.4); packet is discarded (received 11 ...)
[Server:server-three] 11:35:23,985 WARNING [org.jgroups.protocols.UDP]
(OOB-11,hq-cluster,master:server-three) JGRP000010: packet from 10.81.169.177:45688 has different version (3.2.7) than ours (3.6.4); packet is discarded (received 11 identical messages from 10.81.169.177:45688 in the last 66660 ms)
Is this a bug ? https://issues.jboss.org/browse/WFLY-4971 Do anyone faced the same kind of issue ?
You need to isolate your jgroups clusters. You appear to have an existing jgroups cluster (using an older version of jgroups) on your network that uses the same multicast address/port. Make sure each cluster uses a distinct multicast address/port.