Activiti in cluster, change or update process definition through web management console, how to notify all nodes. That is how to synchronized process definition.
If you deploy a new process definition, a new unique identifier will be generated. All the process caches on each of the cluster nodes will auotmatically pick this up and stop using the old ones.
I mean that Process definition does not exist in database, only the key and version of process definition. I deploy a new process defintion in one of cluster nodes, the other nodes only find unique identifier in database, but have not bpmn20.xml to reload.