Writing Repository Governance Services¶
An repository governance service is a specialized connector that performs governance on open metadata repository such as maintaining an open metadata archive. It is hosted in the Repository Governance OMES which is, in turn, running in an engine host OMAG server.
Figure 1: Repository Governance Services
A repository governance service can:
- Register a listener with the Enterprise OMAS Topic to receive notifications from any of the repositories connected via Open Metadata Repository Cohorts.
- Issue requests to find and retrieve metadata instances from any of the repositories connected via Open Metadata Repository Cohorts.
- Incrementally build and store an open metadata archive.
The interface that all repository governance services must implement is defined by
Figure 1: Methods implemented by an archive service
initializeis a standard method for all connectors that is called by the connector broker when the connector is created. The connector is passed the connection object from the configuration and a unique identifier for this instance of the connector.
setAuditLogprovides a logging destination (see Audit Log Framework (ALF)).
setContextsets up the archive context. This provides an interface to the repository services (OMRS) that provide access to the open metadata.
- The ability to register a listener to receive events from the Enterprise OMRS Topic.
- The ability to retrieve metadata instances from any connected open metadata repository.
startindicates that the archive service is completely configured and can begin processing. This call can be used to register a listener with the Enterprise OMRS Topic through the context and to update the archive store with the current state of the metadata in the repositories.
disconnectis called when the server is shutting down. The archive service should free up any resources that it holds since it is not needed any more.
- Metadata Archiving to understand the different mechanisms that use open metadata archives.
- Open Metadata Archives to understand structure of an open metadata archive.
- Configuring an engine host to understand how to set up an archive service.
- Defining a governance engine in a content pack to add
- Writing a Open Metadata Archive Store Connector.
- Loading an Open Metadata Archive at server statup
- Loading an Open Metadata Archive in a running server