ZooKeeper Migration Steps

Collect the following information:


Required Information	Description
Source ZooKeeper hostname (sourceHostname)	The hostname must be one of the hosts running in the ZooKeeper ensemble, which can be found in <NiFi installation dir>/conf/zookeeper.properties. Any of the hostnames declared in the `server.N` properties can be used.
Destination ZooKeeper hostname (destinationHostname)	The hostname must be one of the hosts running in the ZooKeeper ensemble, which can be found in <NiFi installation dir>/conf/zookeeper.properties. Any of the hostnames declared in the `server.N` properties can be used.
Source ZooKeeper port (sourceClientPort)	This can be found in <NiFi installation dir>/conf/zookeeper.properties. The port is specified in the `clientPort` property or at the end of the server string.
Destination ZooKeeper port (destinationClientPort)	This can be found in <NiFi installation dir>/conf/zookeeper.properties. The port is specified in the `clientPort` property or at the end of the server string.
Export data path	Determine the path that will store a json file containing the export of data from ZooKeeper. It must be readable and writable by the user running the zk-migrator tool.
Source ZooKeeper Authentication Information	This information is in <NiFi installation dir>/conf/state-management.xml. For NiFi 0.x, if Creator Only is specified in state-management.xml, you need to supply authentication information using the `-a,--auth` argument with the values from the Username and Password properties in state-management.xml. For NiFi 1.x, supply authentication information using the `-k,--krb-conf` argument. If the state-management.xml specifies Open, no authentication is required.
Destination ZooKeeper Authentication Information	This information is in <NiFi installation dir>/conf/state-management.xml. For NiFi 0.x, if Creator Only is specified in state-management.xml, you need to supply authentication information using the `-a,--auth` argument with the values from the Username and Password properties in state-management.xml. For NiFi 1.x, supply authentication information using the `-k,--krb-conf` argument. If the state-management.xml specifies Open, no authentication is required.
Root path to which NiFi writes data in Source ZooKeeper (sourceRootPath)	This information can be found in `<NiFi installation dir>/conf/state-management.xml` under the Root Node property in the cluster-provider element. (default: `/nifi`)
Root path to which NiFi writes data in Destination ZooKeeper (destinationRootPath)	This information can be found in <NiFi installation dir>/conf/state-management.xml under the Root Node property in the cluster-provider element.

	Note
	As of NiFi 1.10.x, because of an upgrade to ZooKeeper 3.5.x, the migrator may have a permission error "NoAuthException: KeeperErrorCode = NoAuth for /zookeeper/config" when attempting to use / as the destination root path. This is because the /zookeeper/config znode has read-only permissions. Instead use a destination path of /nifi/components or similar.

Stop all processors in the NiFi flow. If you are migrating between two NiFi installations, the flows on both must be stopped.

Export the NiFi component data from the source ZooKeeper. The following command reads from the specified ZooKeeper running on the given hostname:port, using the provided path to the data, and authenticates with ZooKeeper using the given username and password. The data read from ZooKeeper is written to the file provided.

For NiFi 0.x
- For an open ZooKeeper:
  - zk-migrator.sh -r -z sourceHostname:sourceClientPort/sourceRootPath/components -f /path/to/export/zk-source-data.json
- For a ZooKeeper using username:password for authentication:
  - zk-migrator.sh -r -z sourceHostname:sourceClientPort/sourceRootPath/components -a <username:password> -f /path/to/export/zk-source-data.json
For NiFi 1.x
- For an open ZooKeeper:
  - zk-migrator.sh -r -z sourceHostname:sourceClientPort/sourceRootPath/components -f /path/to/export/zk-source-data.json
- For a ZooKeeper using Kerberos for authentication:
  - zk-migrator.sh -r -z sourceHostname:sourceClientPort/sourceRootPath/components -k /path/to/jaasconfig/jaas-config.conf -f /path/to/export/zk-source-data.json

(Optional) If you have used the new NiFi installation to do any processing, you can also export its ZooKeeper data as a backup prior to performing the migration.

For an open ZooKeeper:
- zk-migrator.sh -r -z destinationHostname:destinationClientPort/destinationRootPath/components -f /path/to/export/zk-destination-backup-data.json
For a ZooKeeper using Kerberos for authentication:
- zk-migrator.sh -r -z destinationHostname:destinationClientPort/destinationRootPath/components -k /path/to/jaasconfig/jaas-config.conf -f /path/to/export/zk-destination-backup-data.json

Migrate the ZooKeeper data to the destination ZooKeeper. If the source and destination ZooKeepers are the same, the --ignore-source option can be added to the following examples.

For an open ZooKeeper:
- zk-migrator.sh -s -z destinationHostname:destinationClientPort/destinationRootPath/components -f /path/to/export/zk-source-data.json
For a ZooKeeper using Kerberos for authentication:
- zk-migrator.sh -s -z destinationHostname:destinationClientPort/destinationRootPath/components -k /path/to/jaasconfig/jaas-config.conf -f /path/to/export/zk-source-data.json

Once the migration has completed successfully, start the processors in the NiFi flow. Processing should continue from the point at which it was stopped when the NiFi flow was stopped.