© 2006 Open Grid Forum INFOD Extended Specifications OGF21, Seattle, WA, USA

© 2006 Open Grid Forum 2 Overview Status Steve Fisher (RAL) INFOD prototype Raghul Gunasekaran (UTK) Extended specifications Objectives Some requirements Extensions – some ideas

© 2006 Open Grid Forum 3 Before we Start The INFOD group intends to add extension covering new use cases and potentially simplifying use cases that are already covered This presentation described a set of potential enhancements There is no consensus yet about the extensions – a consensus is about 6 to 12 months away The INFOD group is looking for additional use cases and suggestions

© 2006 Open Grid Forum 4 Objective Improve subscriptions We need even more functionality and flexibility Support relations between publishers and consumers respectively Allow division of labor between publishers and consumers respectively OR – add the notion of a broker Clean up interface REPLACE operation Add as few elements as possible

© 2006 Open Grid Forum 5 Some Use Cases Inform local fire department if average temperature within 20 miles is 2 degrees higher than forecasted and condition red exists Provide weather information to Plume Prediction Services for all chemical sensors located within an area

© 2006 Open Grid Forum 6 Requirements - Other Support lightweight publishers (producers) Allow sensors to outsource publication of information Support lightweight consumers Allow actuators to outsource receiving information

© 2006 Open Grid Forum 7 The INFOD Model Publisher Consumer Subscriber Publisher/ Entry Subscriber Entry Subscription Consumer Entry Data VocabularyProperty Vocabulary Data Source Entry Property Vocabulary Instance Creation of resource Notification (by INFOD registry) Reference (EPR) Notification (by Publishers) EntryResource – not an entry

© 2006 Open Grid Forum 8 The Extended INFOD Model Publisher Consumer Subscriber Publisher Entry Subscriber Entry Subscription Consumer Entry Data VocabularyProperty Vocabulary Data Source Entry Property Vocabulary Instance Producer/Publisher/ Disseminator Producer/Publisher/ Disseminator Entry POBox/Consumer Entry Creation of resource Notification (by INFOD registry) Reference (EPR) Notification (by Publishers) EntryResource – not an entry

© 2006 Open Grid Forum 9 An Alternative – Broker PublisherConsumer Publisher Entry Subscriber Entry Subscription Consumer Entry Data VocabularyProperty Vocabulary Data Source Entry Property Vocabulary Instance Creation of resource Notification (by INFOD registry) References (one or more EPRs) Notification (by Publishers/Brokers) EntryResource – not an entry Broker Subscriber Broker Entry

© 2006 Open Grid Forum 10 (Partial) List of Work Items Association between publishers Association of data sources to multiple publishers Association between consumers Delivery policies Improved subscriptions ?? Brokers Subscriptions to the INFOD registry Distributed INFOD registries Non WS-Notification data movement Improved REPLACE Operation

© 2006 Open Grid Forum 11 Association Between Publishers Publisher should be able to cooperate with each other: Simple publishers; e.g., sensors Focused on creation of data – conditional (data constraints) or unconditional Dissemination functions are out-sourced Full function publishers - disseminators Process subscription and dissemination Support of a wide range of operational characteristics including auditing and tracking Method: Associate publishers to other publishers INFOD registry maintains and explores the relation

© 2006 Open Grid Forum 12 Association of Data Sources Data sources can be associated to multiple publishers Directly through – secondary – publisher data source association Indirectly through association between publishers Publishers can support subscriptions referencing data sources from multiple publishers Report the average temperature in Knoxville if it deviates more than 2 degrees for the forecast – individual sensors are perceived as publishers

© 2006 Open Grid Forum 13 Association Between Consumers Consumers should be able to cooperate with each other: Simple consumers; e.g., actuators Focused on reaction to – new – data Dissemination functions are out-sourced Full function consumers - POBoxes Receive and filter messages Support of a wide range of operational characteristics including auditing and tracking Method: Associate consumers to other consumers INFOD registry maintains and explores the relation

© 2006 Open Grid Forum 14 Message Delivery Policies Create subscription to related consumers – POBoxes to specify: Filters Forwarding – notification, full message Time of delivery EPR of delivery Use XQuery to look into history

© 2006 Open Grid Forum 15 Brokers?? Many messaging or publish/subscribe system support the notion of a broker A broker is a resource acting as publisher, subscriber and consumer A broker consumes, selects, fuses, enriches and disseminates information Broker would keep the publisher and consumer model simple

© 2006 Open Grid Forum 16 Improved Subscriptions Through associations between publishers Subscription can reference data sources from multiple publishers Through extended subscription functionality Additional procedure Reference to registry data Notification with changes

© 2006 Open Grid Forum 17 Subscriptions to the INFOD Registry Use meta data subscriptions to get up- to-date information from INFOD registry INFOD registry is publisher Publisher, subscribers and consumers can act as consumers Notification about subscriptions will be created Structured as any other subscription

© 2006 Open Grid Forum 18 Distributed INFOD Registries Use subscription technology to share information There is no matching across registries

© 2006 Open Grid Forum 19 Non WS-Notification Dissemination Dissemination is currently done with WS-Notification Other Data Movement technologies are desirable to support a variety of operational characteristics Existing/proposed technologies will be considered; e.g., OGSA Data Architecture

© 2006 Open Grid Forum 20 REPLACE Operation Add REPLACE operations Data Sources Property Vocabulary Instances No REPLACE operation for vocabularies Allow selective replacement of elements Use XQuery DELETE to define entries to be removed Keep whatever is not deleted – important for constraints with reference to resources marked with DISABLE NEW

© 2006 Open Grid Forum 21 If you want to contribute : Join our Work session dedicated to the Extended Specifications on Thursday, October 1:30 pm in Discovery A

© 2006 Open Grid Forum 22 Full Copyright Notice Copyright (C) Open Grid Forum (2006). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. The limited permissions granted above are perpetual and will not be revoked by the OGF or its successors or assignees.