1. OPODIS'04 A protocol for recording provenance in service-oriented Grids Paul Groth, Michael Luck, Luc Moreau University of Southampton

2. OPODIS'04 Or…How to show your work. In a Grid

3. OPODIS'04 Contents 1. What is Provenance and why you should care 2. The Grid and Provenance 3. An Architectural Vision 4. PReP 6. What’s next 7. Conclusion

4. OPODIS'04 A Definition Main Entry: prov·e·nance Pronunciation: 'präv-n&n(t)s, 'prä-v&-"nän(t)s Function: noun Etymology: French, from provenir to come forth, originate, from Latin provenire, from pro- forth + venire to come Date: 1785 1 : ORIGIN, SOURCE 2 : the history of ownership of a valued object or work of art or literature The provenance of something is the documentation of process that led to that something i.e. showing your work

5. OPODIS'04 The importance of provenance Process is IMPORTANT Art Wine Drug Discovery Financial Auditing Aerospace …

6. OPODIS'04 The Grid The Grid problem is defined as coordinated resource sharing and problem solving in dynamic, multi- institutional virtual organisations [Foster, Kesselman, Tuecke].

7. OPODIS'04 … and the Provenance Problem Given a set of services in an open grid environment that decide to form a virtual organisation with the aim to produce a given result; How can we determine the process that generated the result, especially after the virtual organisation has been disbanded?

8. OPODIS'04 Provenance Problem cont. Provenance recording should be part of the infrastructure Currently, the Web Services protocol stack and the Open Grid Services Architecture do not provide any support for recording provenance. Methods are generally adhoc and do not interoperate.

9. OPODIS'04 More Definitions Provenance The provenance of some data is the documentation of process that led to the data. Interaction Provenance For some data, interaction provenance is the documentation of interactions between actors that led to the data. Actor Provenance For some data, actor provenance is documentation that can only be provided by a particular actor pertaining to the process that led to the data.

10. OPODIS'04 An Architecture

11. OPODIS'04 Motivating Requirements Verifiability Accountability Reproducibility Repeat Reproduce Preservation Scalability Generality Customisability

12. OPODIS'04 An Architecture with Provenance Support

13. OPODIS'04 PReP- Provenance Recording Protocol client service invocation result record invocation and result record invocation and result negotiate Why record 2 views? Provenance Store Provenance Store Provenance Store

14. OPODIS'04 Multiple Provenance Stores clientservice invocation result Provenance Store invocation and result record invocation and result record clientservice invocation result Provenance Store invocation and result record invocation and result record clientservice invocation result Provenance Store invocation and result record invocation and result record Provenance stores may be shared or different

15. OPODIS'04 Linking Stores clientservice invocation result Provenance Store invocation and result record invocation and result record clientservice invocation result Provenance Store invocation and result record invocation and result record clientservice invocation result Provenance Store invocation and result record invocation and result record Link

16. OPODIS'04 PReP in detail Model PReP using asynchronous message passing. Maps well to any implementation Helpful for scalability Four Phase Protocol Negotiation Invocation Provenance Recording Termination

17. OPODIS'04 PReP’s messages Propose Reply Invoke Result Record Negotiation Record Invocation Record Result Submission Finished Additional Provenance Record Negotiation Ack Record Invocation Ack Record Result Ack Submission Finished Ack Additional Provenance Ack

18. OPODIS'04 PReP’s messages Propose Reply Invoke Result Record Negotiation Record Invocation Record Result Submission Finished Additional Provenance Record Negotiation Ack Record Invocation Ack Record Result Ack Submission Finished Ack Additional Provenance Ack Used for connecting provenance stores and for recording provenance about actors.

19. OPODIS'04 Provenance Store – An abstract state machine Formalise the protocol by formalising the individual entities in the protocol Know exactly how the Provenance Service responds to receipt of messages Use to show a liveness property Something good will eventually happen

20. OPODIS'04 Client and Service State transition diagram Cannot formalise internals, only the response to PReP Show Termination Property

21. OPODIS'04

22. What’s next PReP Version 2 Greater Flexibility In configuration and recorded info Security non-repudiation mutual authentication Fault Tolerant Specification What if you have a lot of data? Look at scalability

23. OPODIS'04 Conclusion Provenance is important Provenance recording must be part of the infrastructure. Standards. PReP provides is a first step. An implementation (PReServ) is available.

24. OPODIS'04 http://www.pasoa.org Where you can download PReServ pg03r@ecs.soton.ac.uk The End