Open Metadata Collection Store Connectors Documentation

The open metadata collection store connectors are used to integrate an existing metadata repository into the the open metadata ecosystem. There are two types of connectors.

The event mapper connector often calls repository connector to expand out the information needed by the OMRS. The links below provide more information.

Getting Started Implementing a New Connector

As implied by the overview above, a logical place to start in implementing a new Open Metadata Collection Store Connector is by implementing the repository connector.

This requires implementing:

Once these minimal starting points are implemented, you should be able to configure the OMAG server chassis as a proxy to your repository connector by following the instructions in using the admin services. Important: this will not necessarily be the end-state pattern you intend to use for your repository connector, but can provide a quick way to start testing its functionality.

This very basic initial scaffold of an implementation allows a connection to be instantiated to your repository, and translation between your repository’s representation of metadata and the open metadata standard types.

The configuration and startup sequence is important, to start with the following should be sufficient (ie. you should not need to configure the access services or event bus initially to just test your OMRSMetadataCollection logic):

  1. Enable access to a cohort, by picking a name for your cohort and POSTing according to the instructions linked.
  2. Enable OMAG Server as a repository proxy, specifying your canonical OMRSRepositoryConnectorProvider class name for the connectorProvider={javaClassName} parameter.
  3. Start the server instance, by POSTing according to the instructions.

You should then be in a position to invoke the REST API endpoints of the OMAG server, which will in turn invoke the various methods of your implemented OMRSMetadataCollection.

Adding an Event Mapper

Once you have the basic OMRSMetadataCollection working, you can then implement an event mapper.

This requires implementing:

The bulk of the logic in the event mapper should then define how events that are received from your repository are processed (translated) into OMRS events: those dealing with Entities, Classifications and Relationships.

Typically you would want to construct such instances by calling into your OMRSMetadataCollection, ensuring you produce the same payloads of information for these instances both through API connectivity and the events.

Once you have the appropriate OMRS object, you can make use of the methods provided by the repositoryEventProcessor, configured by the base class, to publish these to the cohort. For example:

To add the event mapper configuration to the configuration you started with above, add:

  1. Configure the cohort event bus. This can be done first, before any of the other configuration steps above
  2. Configure the event mapper. This can be done nearly last: after all of the other configuration steps above, but before the start of the server instance.