egeria

Open Metadata and Governance

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Governance Engine Open Metadata Access Service (OMAS)

The Governance Engine Open Metadata Access Service (OMAS) provides access to metadata for policy enforcement frameworks such as Apache Ranger. This API simplifies the internal models and structures of the open metadata type model and related structure for the consumers.

As an example, Ranger needs to know how a particular entity is classified so that the classification can be used within a policy (rule). Apache Atlas has a complex graph-oriented model, within which classifications can be multi level - for example a column may be classified as employee_salary whilst employee_salary itself may be classified as SPI. Ranger however just needs to know that the column is SPI, not how we got there. So we convert this complex model into something much more operationally-focused and deliver that over the API. The implementation will follow this graph, and build up a list of all tags that are appropriate to use. Note that in the case of Ranger it is actually the tagsync process that will call the Governance Engine OMAS for this classification information

Ranger can do this today, but via a large number of individual requests to retrieve types and entities. Rather than these lower level queries to the metadata repository services, the Governance Engine OMAS offers result sets to make queries more efficient, and more appropriate notifications.

The module structure for the Governance Engine OMAS is as follows: