Well I am not expert in migrating from a version to another so my answer might not be good enough for you :(. Besides that, I had no time to read the release notes for 1.21.0 and I am not quite sure if anything changed in terms of config files.   Assuming that you will keep the hostname and the port for each nifi node and you are using the embedded zookeeper, you should: 1. Stop the current NiFi instance. 2. Copy the authorizations.xml, authorizers.xml, bootstrap.conf, flow.json.gz, flow.xml.gz, logback.xml, login-identity-providers.xml, nifi.properties, stateless.properties, state-management.xml, users.xml and zookeeper.properties into the conf folder from within your new nifi instance. 3. Make sure that in nifi.properties, on your new instance, you are pointing to the same content repository, database repostiory (and all the other repositories) as in the previous instance --> assuming that you followed the best practices and had all those repositories moved on separate disks. Otherwise, make sure that you process all your data on your old instance and start fresh on your new instance. 4. Start the new NiFi Instance. If you are just interested in migrating just the flows from the canvas, you can add all your flows into a template and save them on your local machine. Afterwards, you can open your new nifi instance, upload your template and add it to your canvas. ... View more