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.
Starting with CFM 22.214.171.124, security has been improved in NiFi and it changed the internal authentication token handling to use HttpOnly Session Cookies. Cookies are specific to a hostname and path, but the browser does not differentiate between different ports on the same host. In case multiple NiFi instances are running on the same node, but listening on different ports, it is required to configure an HTTPS load balancer and setup different context paths for each NiFi instance.
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.