I found the information here
https://nifi.apache.org/docs/nifi-docs/html/administration-guide.html
NiFi Cluster Coordinator: A NiFi Cluster Cluster Coordinator is the node in a NiFI cluster that is responsible for carrying out tasks to manage which nodes are allowed in the cluster and providing the most up-to-date flow to newly joining nodes. When a DataFlow Manager manages a dataflow in a cluster, they are able to do so through the User Interface of any node in the cluster. Any change made is then replicated to all nodes in the cluster.