Connector Broker

The Connector Broker is a top level factory for all types of connectors.  It consists of a client-side java library and a REST service.   Most of the logic to create connectors is in the Java client side library.  This is because connector's themselves are instances of java classes.  They need to be constructed in the JVM of the consuming logic.   The REST service simply supports the retrieval of connection information necessary to instantiate new connector instances. This connection information is typically stored in an open metadata repository.

The Connector Broker's design assumes it is consumed by the java-side client of selected Open Metadata Access Services (OMASs).   This includes:

• Connector Directory OMAS - provides a connector metadata management API for tools and applications.
• Discovery OMAS - provides metadata services for discovery services that are supported by the Open Discovery Framework (ODF).
• Data Scientist OMAS - provides metadata services for data exploration, analytics and machine learning development tools.

The OMAS java client constructs the Connector Broker Java client, passing the server address and port endpoint information for its REST service.   This value is known to the OMAS Java clients since the Connector Broker's REST service is packaged with the OMAS REST services, and so it has the same server/port as the consuming OMAS interfaces.

The Connector Broker's API is shown in Figure 1 below.   Once it is initialized, it offers getConnector() operations to request connector instances either from a connection object or a connection name.  If the name is supplied, the Connector Broker calls its RESTful API to retrieve the connection information (typically from an open metadata repository), constructs a connection object and an instance of the connector provider identified in the connection.   The connector provider is the specialized factory for a specific type of connector.  Once the connector provider has constructed the connector instance, it returned the connector instance to the connector broker, which returns it to the requesting OMAS java client.  The connector may then be used internally by the OMAS, or returned to its caller if the connector is exposed as one of the operations on the OMAS API.

Figure 2 shows the calls between the Java Connector Broker and its REST API.  Notice that on the server-side, the connector broker uses and OMRS Connector to retrieve the connection metadata.  This OMRS Connector is configured in the WAR file for the REST APIs.