Adapter Integration Pattern
The Adapter integration pattern enables existing metadata repositories and their tool sets to integrate into the open metadata ecosystem without needing to embed the Egeria libraries into their servers.
This pattern involves the development of the metadata collection connectors that map between the proprietary metadata formats and the open metadata formats plus manage notifications around the activity occurring with the metadata repository. These connectors are hosted in a special Egeria server called the repository proxy.
A metadata repository needs the following capabilities to support the adapter pattern:
- A remotely callable interface (API) that allows metadata to be queried, created, updated and deleted.
- The generation of event notifications whenever metadata changes in the metadata repository.
The API is wrapped in an OMRS Repository Connector implementation
that maps open metadata repository service calls to the API of
the metadata repository.
The event notifications are captured and mapped into calls back to the OMRS by an OMRS Repository Event Mapper Connector. The OMRS then publishes the resulting OMRS Events to the other metadata repositories in the cohort and to the registered OMASs.
Figure 1 shows the adapter pattern in operation for a fictitious metadata
product called XYZ.
Its OMRS Repository Connector and Event Mapper Connector are running in a Repository Proxy. The repository proxy manages the OMRS Connector and Event Mapper and ensures they are called at appropriate times.
Figure 1: High level operation of the adapter pattern
The development steps to implement the Adapter integration pattern are:
- Determine the mapping between your metadata repository and the open metadata types.
- Create the metadata collection connectors that map between the proprietary metadata formats.
- Package the connectors and appropriate admin services into a repository proxy server.
The Virtual Connector Demo demo includes an example of a repository proxy for IBM’s Information Governance Catalog.
License: CC BY 4.0, Copyright Contributors to the ODPi Egeria project.