THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
An OMRS Connector is a Java class that supports the standard OMRS Connector API. This API defines a call interface to create, search, query, update and delete metadata. The implementation of a specific OMRS connector determines which type(s) of metadata repository it is able to access.
Initially we plan 4 implementations of connectors with the OMRS Connector API. These connector implementations will be part of the Apache Atlas code base.
| Connector | Description | JIRA |
|---|---|---|
| Local Atlas OMRS Connector | This is the connector to a local Apache Atlas metadata repository. It calls directly to Apache Atlas's internal interface for the metadata repository and as such is always deployed in an Apache Atlas Server. | |
| OMRS REST Connector | This is a connector to a remote Apache Atlas repository (or any other metadata repository that supports the OMRS REST APIs). This is the connector used by an open metadata repository to make a direct call to another open metadata repository. It is also used by the Enterprise OMRS Connector described below. | |
| IGC OMRS Connector | This is the connector for retrieving metadata from IBM’s Information Governance Catalog. This connector translates the calls to its OMRS Connector API to IGC's REST API and then translates the results of these calls to appropriate responses on its API. | |
| Enterprise OMRS Connector | This connector can issue calls to multiple OMRS connectors and aggregate the results as if the metadata was stored in a single repository. This is how metadata queries are federated across the metadata repository cluster. Since all implementations of OMRS connectors have the same API, the Enterprise OMRS Connector is able to work will a heterogeneous collection of OMRS connectors. It uses its configuration to create the appropriate instances of the OMRS connectors. |
Every OMRS connector supports the Open Connector Framework (OCF). This means that they use connections to define the network address and user credentials necessary to access a specific instance of a metadata repository.
If an OMRS Connector is included in the Apache Atlas build, then it can be called directly from an OMAS API, or from the Enterprise OMRS Connector, or from the OMRS Adapter (more details in figure 1). When the OMRS Connector is not included in the Atlas build, it can be called from the OMRS Adapter.
Figure 1 shows some potential patterns for the use of OMRS Connectors to access different types of metadata repositories. The letters above each pattern (A, ..., G) refer to the notes below the diagram.
 | |
A | The OMRS Local Connector is hosted in the Apache Atlas server and calls the local internal metadata repository API. Every Atlas server will have one of these connectors. |
| B | The Enterprise OMRS Connector (see here for more details) converts each call to its interface to a call to each of the OMRS connectors that it is configured to work with. It then aggregates the results together for form the response to its call. |
| C | The OMRS REST Connector translates calls to its interface to calls the OMRS REST API of a remote metadata repository. Apache Atlas servers support the OMRS REST API, and other metadata repositories may also implement this interface too. |
| D | The OMRS REST Connector is calling the OMRS REST API that has been implemented by a non-Apache Atlas metadata repository. |
| E | The OMRS REST Connector is calling the OMRS REST API that is implemented by the OMRS adapter. This is a standard OMRS component that runs is its own WAR file (ie outside of the Atlas server). New connector implementations can be introduced into the OMRS Adapter from third parties. The OMRS Adapter translates to OMRS REST API calls to a local OMRS Connector based on configuration. This adapter pattern enables OMRS Connector implementations that are not part of the Atlas Build to be called from standard open metadata components. In this example the OMRS Connector calls the proprietary interface of the XYZ repository. |
| F | This is an alternative adapter pattern where the adapter translates between the OMRS REST API and the repositories proprietary interface rather than going through a connector. This adapter is not an open metadata component - it is provided by a third party. |
| G | The IGC OMRS Connector is an example of a special OMRS connector written to support a specific metadata repository that is not Apache Atlas. This OMRS Connector will be included in the Apache Atlas build so it can be called directly from and OMAS API, the Enterprise OMRS Connector or the OMRS Adapter. |
Together the OMRS Connectors provide a flexible way to federate calls to many types of metadata repositories.