[ https://issues.jboss.org/browse/JGRP-2253?page=com.atlassian.jira.plugin.... ] Sibin Karnavar commented on JGRP-2253: -------------------------------------- In FD_SOCK, startServerSocket() - Here we have an option to specify a start_port and and a port_range. If the specified start_port is already in use, we are trying up to the specified port_range to create the socket address. Why we are not doing the same during setupPingSocket() ? When an application specifies client_bind_port, Why don't FD_SOCK consider the port_range if the specified port is unavailable similar to startServerSocket()? I have turned on debug logs of FD_SOCK and i was able to see that, 2018-06-25 15:01:15.067 DEBUG 6170 --- [FD_SOCK pinger-14,xx-SKS-test_SJX_210620181404_XSJ,ip-xx-xx-xx-xx-60384] org.jgroups.protocols.FD_SOCK : - - ip-xx-xx-xx-xx-60384: failed connecting to ip-XX-xxx-xxx-47443: Address already in use (Bind failed) In AWS environment's , it is not a good practice to define a wide range of inbound open ports. We are more comfortable to define a smaller set of port range as allowed inbound ports for an EC2 instance. The above may not be a solution for the AWS EC2 termination but it is really good to have. I think, as you have mentioned, termination on EC2/AWS may not be closing the socket. Because I have removed my client_bind_port and opened EC2 security group rules to allow any inbound ports for testing purpose but FD_SOCK was still not working as expected. and the DEBUG/TRACE logs were clean with no issues Thanks, Sibin -- This message was sent by Atlassian JIRA (v7.5.0#75005)