@Sivagopal
What version of Apache NiFi are you using?
There are some bugs that could lead to this. I recommend you are using Apache NiFi version 1.21 or newer.
Is it always the same node that is disconnecting or appear random?
Was the ERROR in the nifi-app.log followed by a full stack trace?
- Make sure all nodes in your NiFi cluster are running with the same version of Apache NiFi.
- Make sure that any custom or add-on nars and jars where added to all every node and have proper ownership and permissions.
- Make sure all nodes use the same configured sensitive.props key and algorithm.
Depending on your version of Apache NiFi, you may have a flow.xml.gz or both a flow.xml.gz and flow.json.gz files. On the node that is disconnecting, stop the node, and then rename the existing flow.xml.gz and flow.json.gz (if exists). If you restart NiFi, it will inherit the flow from the cluster when it joins and write new flow.xml.gz and flow.json.gz files to disk.
If you found any of the suggestions/solutions provided helped you with your issue, please take a moment to login and click "Accept as Solution" on one or more of them that helped.
Thank you,
Matt