Cluster fails to merge if instances started simultaneously ---------------------------------------------------------- Key: WFLY-11535 URL: https://issues.jboss.org/browse/WFLY-11535 Project: WildFly Issue Type: Bug Components: Clustering Affects Versions: 14.0.0.Final Environment: Keycloak 4.6.0 official docker image, AWS ECS cluster Reporter: Ian Rodgers Assignee: Paul Ferraro Priority: Major Attachments: standalone-ha.xml, standalone-ha.xml Our Keycloak docker cluster has four instances, clustered using Jgroups/Infinispan as per the standalone-ha.xml. If you start them all simultaneously the "Receive new cluster" logs indicate four separate clusters, each with a single member. They never get merged into the proper single cluster of four members. It seems to be the merging that has changed. The application then fails (we are not using sticky sessions, and each member is ignorant of the sessions on the other members). We can only start the cluster by first starting one instance, then when it is running, starting the other three. The logs then indicate the creation of a single cluster which subsequent instances join. This is consistent behaviour, and when we revert back to v.4.5.0, the issue goes away, Unfortunately we need 4.6.0 for an important fix. On 4.5.0 we get the message "Received new, MERGED cluster view for channel ejb: MergeView::" when it detects a number of subgroups to merge. This never appears in 4.6.0.