When planning how to size and configure Flow Management clusters, it is important to keep in mind. the flow design factors that might impact your cluster sizing needs and the performance of your data flow.
At least three nodes are recommended for a Flow Management cluster used in production environments. NiFi must be running on dedicated nodes.
When NiFi is clustered, you should use an external ZooKeeper cluster. In production deployments, the ZooKeeper instances should not be co-located with the NiFi instances.