Concepts behind OAIS

1. Concepts behind OAIS Archive Task Team WGISS 23 May 21 – 25, 2007 Hanoi, Vietnum

2. OAIS • OAIS – Open Archival Information System • Created by Consultative Committee for Space Data Systems (CCSDS) to standardize basic functionalities of any archive system • Defines components and interactions of a full-featured stand-alone archive • Organized by function • 7 key functional areas • 33 specific functions defined

3. OAIS Organization • Identifies essential functionalities • Provides a standard vocabulary • Improves interoperability between archives • Does not help much in consideration of multiple archives within one facility

4. A different view of OAIS • Try to improve usefulness by reorganizing based on data format: • Data items are contained in packages • Three different formats for data package: • SIP (Submission Information Package) • AIP (Archival Information Package) • DIP (Distribution Information Package) • Most pieces of information will live in all three formats at different times

5. Information Package

6. IP-based view of OAIS archive • Three main regions • Archive Core performs stewardship on data; AIP data is “context-free” • Mission “wrapper” interacts with data providers and converts SIP to AIP • Consumer Access interacts with customers and converts AIP to DIP • Operate within an environment • Execution provides direction, care and feeding • Environment is functionality required to support operations

7. Focus of Responsibility • Archive Core • Problem space: Technology solutions as they relate to data integrity and system performance • Isolation from data provider and customer concerns allows focus on underlying technology • Mission “wrapper” • Problem space: Primarily that of the data provider • Negotiates SIP format for data providers and converts SIPs into AIPs for archival • Consumer Access • Problem space: Customer • Provides catalog, data access, billing and accounting, customer service, outreach • Execution • Problem space: Operation of the archive • Provides tactical business execution, O&M • Environment • Problem space: Archive support • Functionality that enables and supports an operational archive

8. Archive Core Considerations • A major part of the archive that deals with data only in an AIP format, isolated from concerns about data providers or downstream customers • Data is context-neutral so design of this part of the system can be generic • Allow reuse, possible COTS solutions • Focus technical resources on technology to allow better tracking of emerging technology trends • Technology Refresh – In most digital archives, technology becomes obsolete within the required lifetime of data within an archive. With a standard interface to other parts of the system, it is possible to change out the Archive Core without impacting data providers or consumers • Only characterized by: • Type (Active, short-term, long-term, etc.) • Capacity • Performance

9. Benefits in single archive environment • Put skill focus where appropriate • Archive Core specialists focus on data security, emerging technology and methodologies, performance • Execution staff focus on the archive business mission and standardized administration • Improve quality • Mission specialists focus on the data provider • Consumer Access specialists understand the needs of the customer • Enabler of state-of-the-art implementations • Tracking emerging technology is a huge and expensive undertaking. By focusing responsibility of Archive Core staff, it becomes easier to implement advanced technologies that will be required in the future (operational automation, automated fault detection/recovery). • COTS solutions could amortize cost across many archive systems, making it much cheaper than custom designs

10. Multi-archive environment • Deploy and optimize Archive Cores based on archive types needed in the facility rather than by mission • Faster and easier to deploy new missions • Multiple missions can share system resources • Reduce complexity • Reduce expense and system footprint • Reduce operational and maintenance expense • Improve interoperability and control

11. Support multiple missions • With a new mission, have the choice of building an entire new archive or attaching to an existing Archive Core • If already have an Archive Core that provides the required type of storage: • Make a wrapper to attach to the existing Archive Core • If necessary, grow Archive Core capacity to accommodate new archive growth • Add schema to the catalog • Only new development would be if it has a new SIP that you don’t currently handle • Already have staff and resources in place – just add mission specialists

12. Efficient Data Migration • Assuming a standard AIP format, migration merely involves changing the Packaging Information, moving the data and populating catalog

13. Possible Enhancements to OAIS • OAIS model is fairly new (Jan. 2002) and is still evolving • Enhancements that would be beneficial: • Define interfaces to allow clients and external catalogs to “plug in” to the archives • Allow for hybrid architectures

14. Comments and Suggestions? • Any next steps? • How ATT contribute to GEO? • Does WGISS want to explore moving toward? • What are the mutual advantages? • Does ATT should continue? • Close? Unify to other TT ? Open ATTonce a year?