NIFI-7035 The first curator connection issue is logged as ERROR until…

[agentdalecoper]

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Description of PR

Helps not to spam error curator logs on the case of lost node, NIFI-7035.

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[agentdalecoper]

To repeat the issue I managed to change nifi.properties so that nifi.zookeeper.connect.string contained one or more hosts that are not up.
After which nifi-app.log was spammed each 1ms with these sorts of exceptions and stack traces (which are not that helpful).

So the curator lib has out of the box the switch to log only the first problem with the zookeeper connection, and other logs will be in DEBUG level. See https://jira.apache.org/jira/browse/NIFI-7035

[agentdalecoper]

Problem with the mac workflow it seems not related to this PR.

[agentdalecoper]

@shawnweeks
Does it help with the issue?

[markap14]

Thanks @feitgraph I was able to startup a single cluster node with the zookeeper intentionally not started. Saw the tons of logs. Then shutdown, added this property to bootstrap.conf, and restarted. Upon restart, I saw the note that the connection to zookeeper was lost but didn't see errors spewing into the logs. +1 merged to master. Thanks for the fix!

[agentdalecoper]

@markap14 Exactly, thanks for reviewing/testing/helping out.