[ https://issues.jboss.org/browse/JGRP-2293?page=com.atlassian.jira.plugin.... ] Dan Berindei edited comment on JGRP-2293 at 2/6/19 7:06 AM: ------------------------------------------------------------ [~belaban] I ran our test suite a few times without reproducing the failure. Then I got the idea to repeat the offending test 100 times, and I got it to fail both with JGroups 4.0.15.Final and with 4.0.17-SNAPSHOT. Finally I analyzed the logs and I think it is a problem with the test itself, so the fix is good for me. I still haven't managed to run {{LeaveTest}} successfully from the command line though, the nodes never form a cluster because they don't see each other's MPING requests. If I run without {{<jvmarg value="-Djava.net.preferIPv4Stack=true"/>}} I get a sendto error (see below), but with it I get no error message, the nodes just don't see each other. I'd say it's a problem with my environment, but the same test using the same mcast address (230.5.6.7) passes when run from the IDE. {noformat} 12:55:16,177 ERROR (main:[]) [MPING] JGRP000200: failed sending discovery request java.io.IOException: Invalid argument (sendto failed) at java.net.PlainDatagramSocketImpl.send(Native Method) ~[?:1.8.0_171] at java.net.DatagramSocket.send(DatagramSocket.java:693) ~[?:1.8.0_171] at org.jgroups.protocols.MPING.sendMcastDiscoveryRequest(MPING.java:306) [classes/:?] at org.jgroups.protocols.PING.sendDiscoveryRequest(PING.java:64) [classes/:?] at org.jgroups.protocols.PING.findMembers(PING.java:32) [classes/:?] {noformat} was (Author: dan.berindei): [~belaban] I ran our test suite a few times without reproducing the failure. Then I got the idea to repeat the offending test 100 times, and I got it to fail both with JGroups 4.0.15.Final and with 4.0.17-SNAPSHOT. Finally I analyzed the logs and I think it is a problem with the test itself, so the fix is good for me. I still haven't managed to run {{LeaveTest}} successfully from the command line though, the nodes never form a cluster because they don't see each other's MPING requests. If I run without {{<jvmarg value="-Djava.net.preferIPv4Stack=true"/>}} I get a sendto error (see below), but with it I get no error message, the nodes just don't see each other. I'd say it's a problem with my environment, but the same test using the same mcast address (230.0.5.6.7) passes when run from the IDE. {noformat} 12:55:16,177 ERROR (main:[]) [MPING] JGRP000200: failed sending discovery request java.io.IOException: Invalid argument (sendto failed) at java.net.PlainDatagramSocketImpl.send(Native Method) ~[?:1.8.0_171] at java.net.DatagramSocket.send(DatagramSocket.java:693) ~[?:1.8.0_171] at org.jgroups.protocols.MPING.sendMcastDiscoveryRequest(MPING.java:306) [classes/:?] at org.jgroups.protocols.PING.sendDiscoveryRequest(PING.java:64) [classes/:?] at org.jgroups.protocols.PING.findMembers(PING.java:32) [classes/:?] {noformat} -- This message was sent by Atlassian Jira (v7.12.1#712002)