I was able to solve my issue thanks to a post, the things I forgot were the following
- After the clustering plugin is installed by OpenFire server, go to plugins/clustering folder and copy from plugin/clustering/lib folder:
plugin-clustering.jar into OpenFire lib folder.
- If this jar is missing an error “Failed to start or join an existing cluster.” will appear in the Console when enabling the clustering.
- The following exception appears in /logs/error.log: java.lang.ClassNotFoundException: com.jivesoftware.util.cache.JiveConfigurableCacheFactory
coherence-cache-config.xml into OpenFire lib folder. ( Coud not find why this is important ).
- There is a post saying this xml should be inserted into coherence.jar
tangosol-coherence-override.xm into root folder. You need root permissions for this.
If this file is missing, other nodes in the cluster will not appear in Cluster Overview in the Console, only this node )
now there are actually the key configuration is the tangosol-coherence-override file you should be placing on the root directory of your system. it shoul be on /tangosol-coherence-override.xml . remember of your system.
this config should have all your unicast addresses. because if you’re using cloud servers multicast wont work. so you have to use unicast. they different should have exactly the same file. make sure the xml is correct. you should use the oracle documentation as reference http://docs.oracle.com/cd/E18686_01/coh.37/e18677/cluster_setup.htm
read up on the well-known addresses.
you can also specify the ip by changing the startup parameters of your /etc/init.d/openfire script. (I’m using ubuntu os by the way.)