CloudBees has upgraded the JGroups dependency for the CloudBees High Availability plugin, which means instances with JGroups customized through the GUI fail to start and existing
jgroups.xml files may no longer be compatible.
Users with instances using the CloudBees High Availability plugin with JGroups customized through the GUI (under Manage Jenkins > Configure System > High Availability Configuration) must be updated to 18.104.22.168 or higher.
Users with instances that have a customized
jgroups.xml file in
$JENKINS_HOME must update it manually (or switch to using our defaults). See Upgrade guide for instances running High Availability previous to 22.214.171.124 for more information on customizing the configuration.