I am currently using jboss 4.0.5 with the jgroups version that ships with it 2.2.7 SP1 using the TCP communication for clustering. I have three nodes in my cluster and every once in a while two nodes become master and stay master until I restart one of them. The ips of the three nodes are 192.168.1.101, 192.168.1.102, 192.168.1.103. For each node I use its IP address as the TCP bind_addr and use the IPs of each of the other hosts as the TCPPING initial_hosts Below is my clustering config for the first node. <TCP bind_addr="192.168.1.101" start_port="7800" loopback="false" recv_buf_size="2000000" send_buf_size="640000" tcp_nodelay="true" up_thread="false" down_thread="false"/> <TCPPING initial_hosts="192.168.1.102[7800],192.168.1.103[7800]" port_range="0" timeout="3500" num_initial_members="3" up_thread="false" down_thread="false"/> <MERGE2 min_interval="5000" max_interval="10000" up_thread="false" down_thread="false"/> <FD_SOCK down_thread="false" up_thread="false"/> <FD shun="true" up_thread="false" down_thread="false" timeout="10000" max_tries="5"/> <VERIFY_SUSPECT timeout="1500" down_thread="false" up_thread="false" /> <pbcast.NAKACK up_thread="false" down_thread="false" gc_lag="100" retransmit_timeout="300,600,1200,2400,4800"/> <pbcast.STABLE desired_avg_gossip="20000" max_bytes="400000" down_thread="false" up_thread="false" /> <pbcast.GMS join_timeout="5000" join_retry_timeout="2000" shun="true" print_local_addr="true" up_thread="false" down_thread="false"/> <FC max_credits="2000000" down_thread="false" up_thread="false" min_threshold="0.10"/> <FRAG2 frag_size="60000" down_thread="false" up_thread="true"/> <pbcast.STATE_TRANSFER up_thread="false" down_thread="false"/> It will run fine for several days but then eventually two node become master and stay that way. The Barrier service and all of my other single ton MBeans run on both of them causing a lot of issues. Any help on why this is happening and how I can fix it without having to upgrade my whole jboss distribution would be greatly appreciated. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4201899#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...