NIFI-9017: Update Load Balanced Connection logic so that if a node co…

[markap14]

…nnects to the cluster with a different load balancing hostname/port, it starts sending to the new endpoint instead of failing to send to the old endpoint

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Enables X functionality; fixes bug NIFI-YYYY.

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[gresockj]

Code LGTM. I tested this out on a 3-node cluster, changed the nifi.cluster.load.balance.host on one of the nodes, restarted it, and observed that the old NodeIdentifier was replaced with the new one containing the updated host, in onAdded(...). Observed that load balancing continued to work as all 3 nodes received round robin'ed flow files.

+1!

[naddym]

Thanks @markap14. I tested with 3-node cluster backing forth. The changes does resolve the issue. LGTM, +1 to main.