Governance Engine Hosting Servers

An Engine Host is an OMAG Server that hosts one or more governance engines.

Governance engines provide collections of services used to support the governance of assets and the metadata that describes them. They are managed by the engine services (or Open Metadata Engine Services (OMES) to give them their full name) which, in turn run in the Engine Host OMAG Server.

The engine services are:

An engine service is paired with a specific access service running in either a Metadata Access Point or a metadata server.

The name and URL root of the server where the access service is running is needed to configure an engine service. The specific access services are:

The engine host services have an REST API to query the status of the governance engines running in the engine services. The engine services also have a REST API to control and query the work of their governance engines. All of these REST APIs may be called by a view server as part of the support for a user interface.

Figure 1

Figure 1: Engine Host in OMAG server ecosystem

The governance services invoked by the governance engines may access third party technology to perform their responsibilities.

Configuring the Engine Host Server

Each type of OMAG Server is configured by creating a configuration document. The contents of the configuration document identify the type of server and the options on the services it runs.

Figure 2 shows the structure of the configuration document for an engine host.

Figure 2

Figure 2: Configuration Document for an Engine Host

The tasks for configuring an engine host are as follows.

Below is an example of the configuration for a minimal engine host server. It has a single engine service (Asset Analysis OMES) and the default audit log. Both the Governance Engine OMAS used by the engine host services and the Discovery Engine OMAS used by the Asset Analysis OMES are running on the metadata server called myMetadataServer.

    "class": "OMAGServerConfigResponse",
    "relatedHTTPCode": 200,
    "omagserverConfig": {
        "class": "OMAGServerConfig",
        "versionId": "V2.0",
        "localServerId": "8b745d03-5ffc-4978-81ab-bd3d5156eebe",
        "localServerName": "myserver",
        "localServerType": "Open Metadata and Governance Server",
        "localServerURL": "https://localhost:9443",
        "localServerUserId": "OMAGServer",
        "maxPageSize": 1000,
        "engineHostServicesConfig": {
            "omagserverPlatformRootURL": "https://localhost:9443",
            "omagserverName": "myMetadataServer",
            "engineServices": [
                    "class": "EngineServiceConfig",
                    "engineId": 6000,
                    "engineQualifiedName": "Asset Analysis",
                    "engineServiceFullName": "Asset Analysis OMES",
                    "engineServiceURLMarker": "asset-analysis",
                    "engineServiceDescription": "Analyses the content of an asset's real world counterpart, generates annotations in an open discovery report that is attached to the asset in the open metadata repositories .",
                    "engineServiceWiki": "",
                    "engines" : [ {"engineId" : "daff1dca-984b-4b8a-8a8f-febaf72b82a8",
                                   "engineName" : "engine1", 
                                   "engineUserId" : "engine1UserId"},
                                  {"engineId" : "a80aa0f8-2ea0-4f84-b613-d68becba2693",
                                   "engineName" : "engine2", 
                                   "engineUserId" : "engine2UserId"} ],
                    "engineServiceOperationalStatus": "ENABLED",
                    "engineServiceAdminClass": "org.odpi.openmetadata.engineservices.assetanalysis.admin.AssetAnalysisAdmin",
                    "omagserverPlatformRootURL": "https://localhost:9443",
                    "omagserverName": "myMetadataServer"
        "repositoryServicesConfig": {
            "class": "RepositoryServicesConfig",
            "auditLogConnections": [
                    "class": "Connection",
                    "headerVersion": 0,
                    "displayName": "Console",
                    "connectorType": {
                        "class": "ConnectorType",
                        "headerVersion": 0,
                        "type": {
                            "class": "ElementType",
                            "headerVersion": 0,
                            "elementOrigin": "LOCAL_COHORT",
                            "elementVersion": 0,
                            "elementTypeId": "954421eb-33a6-462d-a8ca-b5709a1bd0d4",
                            "elementTypeName": "ConnectorType",
                            "elementTypeVersion": 1,
                            "elementTypeDescription": "A set of properties describing a type of connector."
                        "guid": "4afac741-3dcc-4c60-a4ca-a6dede994e3f",
                        "qualifiedName": "Console Audit Log Store Connector",
                        "displayName": "Console Audit Log Store Connector",
                        "description": "Connector supports logging of audit log messages to stdout.",
                        "connectorProviderClassName": "org.odpi.openmetadata.adapters.repositoryservices.auditlogstore.console.ConsoleAuditLogStoreProvider"
                    "configurationProperties": {
                        "supportedSeverities": [
        "auditTrail": [
            "Tue Dec 08 18:38:32 GMT 2020 me updated configuration for engine service asset-analysis.",
            "Tue Dec 08 18:43:47 GMT 2020 me set up default audit log destinations."

Further information

More information on the governance engines are available below:

Return to the Governance Server Types

License: CC BY 4.0, Copyright Contributors to the ODPi Egeria project.