OMRS Component Overview

Figure 1 shows the external APIs for the OMRS.

On the left hand side is the administration interface used by the OMAG server. This is where configuration is passed to the OMRS, and status and other relevant information is made available to the OMAG Administration Services.

Along the top is the interface with the Open Metadata Access Services. The OMRS provides access to the open metadata repositories through both a call API (see Enterprise OMRS Repository Connector) and an event topic (see Federated OMRS Topic ).

On the right hand side is the Open Metadata Repository Services (OMRS) REST API that supports calls to remote open metadata repositories.

Figure 1: OMRS System Context Diagram

Along the bottom are the six types of connectors that provide the OMRS with access to the stores and system resources it needs to support the OMAS.

The connectors enable the OMRS to be deployed into different types of server environments and connect with different types of infrastructure and services. Repository connectors provide a common interface for metadata repositories. The OMRS store connectors can range from simple files stores to enterprise / cloud provider admin repositories and the event topic can support different types of messaging infrastructure.

Inside the OMRS are 4 major groups of components: Enterprise Repository Services, Administration Services, Cohort Services and Local Repository Services

Figure 2: Component Overview (level 1)

Enterprise Repository Services provides a virtual metadata repository by combining the content of multiple open metadata repositories and delivering this metadata through a single API and event topic. The Enterprise Repository Services provide the enterprise access metadata support for the OMASs.
Administration Services drive the initialization of the OMRS at server start up plus access to the OMRS's internal status. It relies on the OMAG Server to supply it with the configuration information to initialize the connectors it should use and connector with other open metadata servers.
Cohort Services manage the local server's membership in one or more open metadata repository cohorts.
Local Repository Services manage the local server's open metadata repository.

The OMRS is highly configurable to support the different OMAG Server Roles. Figure 3 below shows the different combinations:

OMRS supporting the OMASs with access to a single, local only server - with no connectivity to other open metadata repositories.

OMRS supporting a server with no local repository - so that all metadata for the OMASs is coming through the cohort services from remote metadata repositories. This is the caller integration pattern.

OMRS supporting a simple repository proxy server. The OMASs are not deployed and the local repository is configured to connect as an adapter for a non-native open metadata repository. The cohort services connect this metadata repository with other members in one or more cohorts. This is called the adapter integration pattern.

This final picture shows all of the components in operation, supporting the OMASs with a local repository and connectivity to other repositories through the cohort servers.

Figure 3: Different combinations of OMRS components to enable different OMAG Server roles

The different combinations of operation required means that the OMRS components need to be flexible and communicate with one another through well-defined interfaces so that component implementations can be swapped in and out to support different configurations.

Figure 4 shows the main components of OMRS.

Figure 4: Component Overview (level 2)

The components are:

OMRS Operational Services - supports the admin interface for the OMRS
OMRS Configuration Factory - manages default values and creation of connectors
OMRS Audit Log - manages the storage and retrieval of audit log records.
OMRS Archive Manager - manages the loading of open metadata archives.

OMRS Enterprise Connector Manager - manages the registration of open metadata repositories with the Enterprise OMRS Connector.
Enterprise OMRS Repository Connector - provides the call API for OMASs to get access to open metadata.

Enterprise OMRS Connector Provider - OCF compliant factory for Enterprise OMRS Repository Connectors.
Enterprise OMRS Metadata Collection - manages the calls to retrieve metadata from all registered metadata repositories.

OMRS Metadata Highway Manager - manages the collection of cohorts that this server is connected to.
OMRS Cohort Manager - manages the components for connectivity to a single cohort.
OMRS Repository Event Manager - manages the distribution of TypeDef and instances events amongst the OMRS components within a server.
OMRS Event Publisher - formats and sends events to the OMRS Topic.
OMRS Event Listener - receives events from an OMRS Topic and passes them to registered OMRS Components.
OMRS Cohort Registry - manages the exchange of registration events with other members of an open metadata repository cohort and stores details of the cohort's membership in the Cohort Registry Store.

Local OMRS Repository Connector - supports a call interface to the local repository.
Local OMRS Connector Provider - OCF compliant factory for the Local OMRS Repository Connector.
Local OMRS Metadata Collection - supports the calls to manage metadata in the local repository.
Local OMRS TypeDef Manager - manages an in-memory cache of TypeDefs supported by the local repository.
Local OMRS Instance Event Processor - manages the processing of incoming events relating to metadata instances.

OMRS Repository REST Services - server-side support for the OMRS Repository REST API.
OMRS REST Connector Provider - OCF compliant factory for an OMRS REST Repository Connector.
OMRS REST Repository Connector - supports a call interface for the OMRS Repository REST API.
OMRS REST Metadata Collection - issues REST calls to a remote open metadata repository on behalf of the OMRS REST Repository Connector.

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Yao Li

Yao Li