JBossDeveloper

That's very interestingthradec. I just took a look at your dig response (the one that you pasted previously in this thread) and it seems your using DNS A Records (not SRVs). Therefore, you should not be affected by this change. Maybe there's something more that changed in JGroups that fixed this behavior. belaban What do you think?

If this issue happens again in your cluster, would you be able to dump dig output and Pod IPs? I start to think that maybe somehow those two get out of sync?

Thanks Tomas and Thomas! This does seem to fix the issue. Here's the Dockerfile I'm using:

FROM jboss/keycloak:5.0.0
ADD https://netix.dl.sourceforge.net/project/javagroups/JGroups/4.0.19.Final/jgroups-4.0.19.Final.jar /opt/jboss/keycloak/modules/system/layers/base/org/jgroups/main/
USER root
RUN chmod 644 /opt/jboss/keycloak/modules/system/layers/base/org/jgroups/main/jgroups-4.0.19.Final.jar
RUN chown jboss:root /opt/jboss/keycloak/modules/system/layers/base/org/jgroups/main/jgroups-4.0.19.Final.jar
RUN rm -f /opt/jboss/keycloak/modules/system/layers/base/org/jgroups/main/jgroups-4.0.15.Final.jar
USER jboss
RUN sed -i 's/jgroups-4.0.15.Final.jar/jgroups-4.0.19.Final.jar/' /opt/jboss/keycloak/modules/system/layers/base/org/jgroups/main/module.xml

Thanks for the useful snippet!

Btw. with recent docker versions this should do the trick as well:

# Patch JGroups Module for https://developer.jboss.org/message/988797?et=watches.email.thread#988797
ADD --chown=jboss:jboss https://netix.dl.sourceforge.net/project/javagroups/JGroups/4.0.19.Final/jgroups-4.0.19.Final.jar /opt/jboss/keycloak/modules/system/layers/base/org/jgroups/main/
RUN sed -i 's/jgroups-4.0.15.Final.jar/jgroups-4.0.19.Final.jar/' /opt/jboss/keycloak/modules/system/layers/base/org/jgroups/main/module.xml

That's much tidier. Thanks for improving my Docker fu.