Egeria’s runtime connectors

Connectors enable Egeria to operate in many environments by providing plug-in points for the runtime services it needs to operate. Most of these connectors relate to persistent storage, or connections to distributed services.

Open Metadata Topic Connectors

The Open Metadata Topic Connectors are used by Egeria to read and write events to a topic managed by an event broker. These events contain notifications relating to changes in metadata and the topic provides an asynchronous event exchange service hosted in the event broker.

Figure 1

Figure 1: Open Metadata Topic Connectors

The Open Metadata Topic Connectors connect servers into an open metadata repository cohort and exchange notifications through the Open Metadata Access Services (OMAS)’s topics called the InTopic and OutTopic.

Egeria provides a single implementation of an open metadata connector for Apache Kafka that it uses by default.

The definition of the connector interface for these connectors is defined in the repository-services-api module in the org.odpi.openmetadata.repositoryservices.connectors.openmetadatatopic Java package.

It is configured in the Egeria OMAG Servers through the Event Bus Configuration.

Configuration Document Store Connectors

The configuration store connectors contain the connector implementations that manage the Configuration Documents for OMAG Servers.

Figure 2

Figure 2: Configuration Document Store Connector

There is one configuration document store connector defined for each OMAG Server Platform.

There are two implementations of the configuration document store connector provided by Egeria: one for an encrypted store (default) and the other for a plain text store.

The definition of the connector interface for these connectors is defined in the admin-services-api module in the org.odpi.openmetadata.adminservices.store Java package.

Configuring a configuration store connector in the OMAG Server Platform is described in the Administration Guide. If no connector is configured, the OMAG Server Platform uses the Encrypted File Configuration Store Connector.

Cohort Registry Store Connectors

The cohort registry store connectors store the open metadata repository cohort membership details used and maintained by the cohort registry. The cohort protocols are peer-to-peer and hence there is a cohort registry (with a cohort registry store) for each member of a cohort.

Figure 3

Figure 3: Open Metadata Topic Connectors

Egeria provides a single implementation of a cohort registry store connector:

The definition of the connector interface for these connectors is defined in the repository-services-api module in the org.odpi.openmetadata.repositoryservices.connectors.stores.cohortregistrystore Java package.

Open Metadata Archive Store Connectors

The open metadata archive store connectors can read and write open metadata archives. Open metadata archives store open metadata types and instances for sharing, or for back up. These archives can be loaded into an OMAG Server at start up or added to a running OMAG Server.

Figure 4

Figure 4: Open Metadata Archive Store Connector

Egeria provides a single implementation of the open metadata archive store connector:

The definition of the connector interface for these connectors is defined in the repository-services-api module in the org.odpi.openmetadata.repositoryservices.connectors.stores.archivestore Java package.

Audit Log Destination Connectors

The audit log destination connectors support different destinations for audit log records. Multiple of these connectors can be active in an OMAG Server at any one time and they can each be configured to only process particular types of audit log records.

Figure 5

Figure 5: Audit Log Destination Connector

Below are the connector implementations provided by Egeria

The definition of the connector interface for these connectors is defined in the repository-services-api module in the org.odpi.openmetadata.repositoryservices.connectors.stores.auditlogstore Java package.

There is more information on the use of audit logging in the Diagnostic Guide.

REST Client Connectors

Egeria makes extensive use of REST API calls for synchronous (request-response) communication with its own deployed runtimes and third party technologies. The client connectors are used to issue the REST API calls. Egeria provides a single implementation for Spring.

This is embedded in Egeria’s clients.

Figure 6

Figure 6: REST Client Connector

The definition of the connector interface for these connectors is defined in the rest-client-connector-api module in the org.odpi.openmetadata.adapters.connectors.restclients Java package.

Cohort Member Client Connector

Members of an Open Metadata Repository Cohort provide the other cohort members with a Connection to a connector that supports the OMRSRepositoryConnector interface during the cohort registration process. This connector translates calls to retrieve and maintain metadata in the member’s repository into remote calls to the real repository.

Figure 7

Figure 7: Cohort Member Client Connector used for federating queries across the cohort

Egeria’s Open Metadata Repository Services (OMRS) provides a default REST API implementation and a corresponding client:

The connection for this connector is configured in the LocalRepositoryRemoteConnection property of the cohort member’s Local Repository Configuration.

The definition of the connector interface for these connectors is defined in the repository-services-api module in the org.odpi.openmetadata.repositoryservices.connectors.stores.metadatacollectionstore.repositoryconnector Java package. It is the same interface as the repository connectors that are used to provide the local repository to a metadata server so that the Open Metadata Repository Services (OMRS) issue calls to the same interface irrespective of whether the call is to the local repository or a remote cohort member.

Further information



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