The discovery server is an OMAG Server that is able to host one or more discovery engines.
A discovery engine is the execution environment for special types of connectors called discovery services. Each discovery service implements a specific type of analysis. This analysis may be looking at the metadata about the assets stored in the open metadata repositories, or it may look into the content of the physical asset itself. The result of its analysis is stored in an open metadata repository and linked off of the asset’s description.
The discovery engine defines a set of discovery services. Its definition is stored in an open metadata repository and maintained through the Discovery Engine OMAS’s configuration API.
Discovery servers are deployed close to the physical assets they are analysing. They connect to the Discovery Engine OMAS running in a metadata server to provide metadata about assets and to store the results of the discovery service’s analysis.
Figure 1 shows the discovery server connected to other OMAG Servers. The discovery server has a REST API to request that specific types of analysis are
Figure 1: How the discovery server connects to other OMAG Servers
Multiple discovery servers can run the same discovery engines. They can also connect to the same metadata server.
Configuring the Discovery Server
The configuration for the discovery server is as follows:
- Setting basic properties for an OMAG server
- Configuring the audit log destinations
- Configuring the server security connector
- Configuring the discovery engine services
The Discovery Engine OMAS describes how to configure discovery engines and discovery services for your discovery server.
The Discovery Engine Service supports REST APIs for requesting metadata discovery services on specific assets or groups of assets.
The Open Discovery Framework (ODF) provides a definition of the interfaces for a discovery service. If a discovery service follows the specification of the open discovery framework in its implementation then it can be run in the Egeria Discovery Server. Link to the ODF if you are interested in writing new discovery services.