Attachment 4 - external_interface.docx

ATTACHMENT 4

DAS EXTERNAL INTERFACE

External Interface Architecture and Approach Figure 1shows the NARA Systems Interface planned as the systems are modernized and deployed. Within the scope of the Description and Authority Services solution project are Authority interfaces to the ARCIS, ERA, and HMS systems. Description Services has interfaces from ERA and HMS and provides an interface to OPA.

Figure 1: NARA Systems Interfaces

Interface Approach Most current interfaces rely on a file passing approach as the means for exchanging information between systems. In a service oriented approach to interfaces, information exchanges rely on real-time messages between systems to pass, retrieve, or validate data. While we would like DAS interfaces to behave in a real-time service oriented manner, we recognize that the ARCIS, HMS, ERA, and OPA systems may require modifications to consume or publish service oriented interface operations. With that in mind, we will be applying SOA design principles that will allow for the current interface mechanisms to be accomplished, while allowing for easy transitions to a real-time service oriented approach as the consuming or providing systems are modified.

The architecture to support this approach is shown in Figure 2. This interface architecture uses the message queue paradigm to accomplish the current interface requirements, but it can be easily switched to one that is real-time Web service, an ftp site, or some other target channel. In this diagram the external interface service could represent ARCIS, OPA, ERA, or HMS. The idea here would be that the external interface will eventually be listening on the ExternalInterfaceQueue, but until the ExternalConsumer is ready to do that, an GapProcess will handle the incoming queue data and move it to the current mode of communication (in this case somewhere on the FileSystem). This dynamic behavior is facilitated using the policy driven routing and transformation capabilities that are part of the JBoss SOA Platform Enterprise Service Bus (ESB).

Figure 2: DAS Interface Architecture Design When the ExternalConsumer is ready to consume the data from the message queue, the GapProcess will be stopped, leaving the ExternalInterfaceQueue alone as the in-service mechanism for exchanging data between systems. This same pattern holds true for Web-services and other interface mechanisms; just exchange ExternalInterfaceWebService for ExternalInterfaceQueue and the rest of the narrative remains the same. This architecture and design allows for the greatest flexibility in meeting the immediate interface style requirements while enabling future service oriented interface behavior.

The following sections describe the high level architecture and design considerations for each external interface within the scope of the Description and Authority Services solution.

image1.emf oleObject1.bin Asset Catalog (ACE)

New Description Service (Jan. 2013)

ARC C/S (Descriptions and Authorities)

OPA Web

ERA Transfer Request (TR Metadata for all records)

HMS

(preliminary descriptions, non-electronic records)

Archives.gov

AAD

TR Metadata

Prelim. Descriptions

New Authority Service (Jan. 2013)

If marked as open, copied to

Only 7 AAD series in 2010;

remaining functionality post-2012

2010-2012 (link only until new Services are ready)

OPA Reference Copy Storage

TR Metadata

ARCIS

Non-electronic

ERA BASE

E-Records

Ingested into

All electronic, some physical records (direct offers) image2.png