Migrating flow storage

Provides steps for migrating your local file system, git, or database table flow storage.

Local file system flow storage (FileSystemFlowPersistenceProvider)

This provider is the default Flow Persistence Provider.

Confirm the configuration of the flow storage directory specified in the source registry providers.xml:


<flowPersistenceProvider>
<class>org.apache.nifi.registry.provider.flow.FileSystemFlowPersistenceProvider</class>
<property name="Flow Storage Directory">./flow_storage</property>
</flowPersistenceProvider>

Copy the flow storage directory from the source registry installation to the location specified by the Providers: Default Flow Persistence File Provider Property - Flow Storage Directory (xml.providers.flowPersistenceProvider.file-provider.property.Flow Storage Directory) configuration property in the destination registry. The default directory path in CFM 2.1.5 is /var/lib/nifiregistry/flow_storage.

Git flow storage (GitFlowPersistenceProvider)

This provider stores flow contents under a Git directory.

Confirm the configuration of the flow storage directory specified in the source registry providers.xml:


<flowPersistenceProvider>
<class>org.apache.nifi.registry.provider.flow.git.GitFlowPersistenceProvider</class>
        <property name="Flow Storage Directory">./your_repo</property>
        <property name="Remote To Push">origin</property>
        <property name="Remote Access User">git_user</property>
        <property name="Remote Access Password">git_password</property>
</flowPersistenceProvider>

In the git repository directory, run git remote -v to show the URL of the remote.
Clone the git repository in the destination environment.
Configure the destination registry to point at the git repo. In Cloudera Manager:
- Uncheck Providers: Enable File Flow Persistence Provider (xml.providers.flowPersistenceProvider.file-provider.enabled) so that FileSystemFlowPersistenceProvider is no longer enabled
- Find the NiFi Registry configuration property NiFi Registry Advanced Configuration Snippet (Safety Valve) for staging/providers.xml. Add the following snippets:
  - Name:
```
xml.providers.flowPersistenceProvider.git-provider.enabled
```
    Value: true
  - Name:
```
xml.providers.flowPersistenceProvider.git-provider.class
```
    Value: org.apache.nifi.registry.provider.flow.git.GitFlowPersistenceProvider
  - Name:
```
xml.providers.flowPersistenceProvider.git-provider.property.Flow Storage
                Directory
```
    Value: ./your_repo
  - Name:
```
xml.providers.flowPersistenceProvider.git-provider.property.Remote To
                Push
```
    Value: origin
  - Name:
```
xml.providers.flowPersistenceProvider.git-provider.property.Remote Access
                User
```
    Value: git_user
  - Name:
```
xml.providers.flowPersistenceProvider.git-provider.property.Remote Access
        Password
```
    Value: git_password
Save the changes.

Database table storage (DatabaseFlowPersistenceProvider)

This provider leverages the same database used for the metadata database.

Confirm the configuration of the flow storage directory specified in the source registry providers.xml:


<flowPersistenceProvider>
<class>org.apache.nifi.registry.provider.flow.DatabaseFlowPersistenceProvider</class>
</flowPersistenceProvider>

Configure the destination registry. In Cloudera Manager:
- Uncheck Providers: Enable File Flow Persistence Provider (xml.providers.flowPersistenceProvider.file-provider.enabled) so that FileSystemFlowPersistenceProvider is no longer enabled
- Find the NiFi Registry configuration property NiFi Registry Advanced Configuration Snippet (Safety Valve) for staging/providers.xml. Add the following snippets:
  - Name:
```
xml.providers.flowPersistenceProvider.database-provider.enabled
```
    Value: true
  - Name:
```
xml.providers.flowPersistenceProvider.database-provider.class
```
    Value: org.apache.nifi.registry.provider.flow.DatabaseFlowPersistenceProvider
Save the changes.

note

If the versioned flows have nested version controlled process groups, you must update the registry URL in the stored flows, as they reference the source NiFi Registry. For example, a flow snapshot file would have this sample content:


"versionedFlowCoordinates" : {
            "bucketId" : "4d00e96b-dd33-447a-81bf-a240832e3272",
            "flowId" : "873ef981-48c1-41c2-9c58-89c6ae93d891",
            "registryUrl" : "https://hdf_registry_hostname:61080",
            "version" : 1
          }

Replace the HDF Registry URL with the CFM Registry URL in each of the flow snapshot files.

After you finish

When you having completed the flow storage migration, you may proceed by migrating your bundle storage configurations