@midee    I am not clearly following your use case. FlowFiles consist of two parts, FlowFile attributes/metadata and FlowFile content. You give example with "customefields_12345" and "customefields_12346". Does this mean one FlowFile may have multiple "customefields_<some string>" attributes assigned to it? How do you want to route FlowFiles where only some of those customfield attributes are null while others are not? There are multiple ways to handle this using NiFi Expression Language (NEL) [1] and the routeOnAttribute [2] processor.     ${anyMatchingAttribute("customfield.*"):isEmpty()}     Above would return "true" if ANY of the NiFi FlowFile attributes starting with "customefield" is empty. note: The isEmpty function returns true if the Subject is null, does not contain any characters or contains only white-space (new line, carriage return, space, tab), false otherwise. There is another NEL subjectless function that would return "true" only if ALL FlowFileAttributes matching the Java regular expression were empty:   ${allMatchingAttributes("customfield.*"):isEmpty()}     With the RouteOnAttribute processor you create/add dynamic properties and each of those becomes a new routable relationship on the processor. if the NEL statement configured for that dynamic property returns true that FlowFile routes to that relationship.  Any FlowFile that does not return true for dynamic properties will get routed to the pre-existing relationship named "unmatched".   [1] https://nifi.apache.org/docs/nifi-docs/html/expression-language-guide.html [2] https://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-standard-nar/1.13.2/org.apache.nifi.processors.standard.RouteOnAttribute/index.html   If you found this addressed your query, please take a moment to login and click "Accept" on this solution. Thank you, Matt   ... View more

@hegdemahendra  The NiFi CLI toolkit [1] can help here to an extent. This toolkit provides the following NiFi-Registry capabilities: registry current-user registry list-buckets registry create-bucket registry delete-bucket registry list-flows registry create-flow registry delete-flow registry list-flow-versions registry export-flow-version registry import-flow-version registry sync-flow-versions registry transfer-flow-version registry diff-flow-versions registry upload-bundle registry upload-bundles registry list-bundle-groups registry list-bundle-artifacts registry list-bundle-versions registry download-bundle registry get-bundle-checksum registry list-extension-tags registry list-extensions registry list-users registry create-user registry update-user registry list-user-groups registry create-user-group registry update-user-group registry get-policy registry update-policy registry update-bucket-policy You can get a description of each by executing:   <path to>/cli.sh registry sync-flow-versions -h   Since you are changing FlowPersistence providers and not trying to sync flows to a new NiFi-Registry, You really can't use the above "sync-flow-versions" function. Plus, I really don't see it even in that scenario being able to accomplish your goal because you would end up with new flow ids.  When you create a bucket in NiFi-Registry it is assigned a bucket if (random uuid). When you version control a Process Group (PG) in NiFi, you choose an existing bucket and it first creates a new flow id (Random UUID assigned to the flow).  Then the initial version 1 of that PG flow is created and assigned to that flow id in the NiFi-Registry.  Since you cannot force the flow id assigned UUID, syncing flows from registry 1 to registry 2, would not track to your version controlled PGs in your NiFI because of change in flow id. In your scenario, you would need to export all your flows (version by version and it is important you keep rack of the version fo the flow you extract).  So for a flow with ID XYZ you may have 6 versions.  This means you would use: registry export-flow-version I'd suggest naming the produced json file using source flow id and flow version like XYZ_v1.json, XYZ_v2.json, etc... Example:   ./cli.sh registry export-flow-version -ot json -u http://<nifi-registry hostname>:<port>/ -f c97fd570-e2ef-4001-98c9-8810244b6015 -fv 1 -o /tmp/c97fd570-e2ef-4001-98c9-8810244b6015_ver1.json   You should then save off your original DB.   Delete all existing flows so all you have are your original buckets Then you would need to take all these exported flows and import them back in to registry after switching to your new persistence provider.  Now keep in mind before importing each flow version you must first create a new flow within the correct still existing buckets. Keep track of these newly assigned flow ids and which original flow id you are importing in to them (very important) Then you MUST import each new flow in exact version 1 to version x order.  If you import version 5 of flow XYZ first it will become version 1 within that new flow Id.   The version persisted in the output json is not used when importing, it is assigned the next incremental version in the new flow id. Once you are done here you have a bunch of new flow ids with all your versions imported. Now you need to go edit your flow.xml.gz in NiFi. For every version controlled PG in that flow.xml.gz you will find a section that looks like this:   <versionControlInformation> <registryId>912e8161-0176-1000-ffff-ffff98135aca</registryId> <bucketId>0cab84ff-399b-4113-9767-687e8e33e48a</bucketId> <bucketName>bucket-name</bucketName> <flowId>136b3ba8-bc6f-46dd-afe5-235a80ef8cfe</flowId> <flowName>flow-name</flowName> <flowDescription/> <version>5</version> </versionControlInformation>   Everything here should remain the same except fro the change in "flowId" This would allow you to do a global search and replace on "<flowId>original id</flowId>" to "<flowId>new id</flowId>". Make sure you stop all NiFi nodes,  put same modified flow.xml.gz on all nodes (backup original), and start NiFi nodes again.  Your PGs should now be tracking to your new flows imported in your registry now backed by the gitFlowPersistenceProvider. [1] https://nifi.apache.org/docs/nifi-docs/html/toolkit-guide.html#nifi_CLI   Sorry there is no automated path for this.   If you found this addressed your query, please take a moment to login and click "Accept" on those solutions which assisted you. Thanks, Matt ... View more