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

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

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

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: : 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

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

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].

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?

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.

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.

OPODIS'04 An Architecture

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

OPODIS'04 An Architecture with Provenance Support

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

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

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

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

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

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.

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

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

OPODIS'04

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

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.

OPODIS'04 Where you can download PReServ The End