Event Notification Protocol

1
Event Notification Protocol

• Surendra Reddy
• Oracle Corporation

2
Agenda

• Motivation
• Event Notification Protocol - Overview
• ENP - Architecture
• Conclusion

3
Motivation

• Highly distributed software development
  environments -- software change monitoring and
  integration is a big challenge
• externalization of database triggers, Queue
  propagation
• Instant Messaging

4
ENP - Overview

• HTTPDatabase based infrastructure
• HTTP based light-weight, many-to-many
  communication service between distributed
  database servers
• publish and subscribe model
• describe events using PL/SQL XML XQL
• user defined notification filters/rules(PL/SQL
  for event specification )

5
ENP - Overview

• Notifications are fine grained information units
• anonymous notifications

6
ENP - Architecture
Producers
Consumers
Event Flow
Event Notification Protocol
DATABASE
Consumer
Producer
7
ENP - Architecture

• Based on WebDAV extensions to HTTP plus
  additional headers
• distributed consumers and producers
  publish/subscribe with ENP
• rules contains events of interest and actions to
  be performed in response to an occurrence of an
  event

8
ENP - Architecture

• Service characteristics
• extensibility of services
• Uses polling and synchronous notification
  mechanisms

9
ENP - Architecture

• doesnt depend on service architecture
• location independent

10
ENP - Architecture

• Notification Delivery
• sends/routes/queues notifications for subscribers
• propagates only if interest exists
• store and forward events

11
ENP - Architecture

• Routing
• matches events with filters( filtering based on
  attributes and content data)
• point-to-point delivery of notifications

12
Conclusion

• ENP - ENP communication to bring notifications
  closer to consumers
• issues associated with interpretation of time in
  event rules

13
Conclusion

• event persistence and administration?
• access controls and digital signatures
• Event across fire-walls?
• ENP draft is available at http//www.ietf.org/inte
  rnet-drafts/draft-reddy-enp-protocol-00.txt