1. INFOD-WG Implementation
F2F Knoxville, TS

2. Evolutionary Prototyping
There are 3 main parts to an INFOD implementation:
an INFOD Web Service Registry to which publishers, subscribers, consumers and vocabularies can be added.
some simple web services testing the sending of data from the publisher services to consumer services.
creation of the subscription processing component in the INFOD Registry.
(Note: A full reasoning engine capable of evaluating complex constraints and able to handle mutual filtering could be a significant task on its own.)
Open source code will be kept in SourceForge with a separately maintained area for each group producing implementations. 2

3. Object with properties
The Specification
Data
Vocabularies
Property
Vocabularies
Publisher
Object with properties
Data
Consumer
Subscription
Subscriber
Registry
Registration
Notification
Flow of Data 3

4. Functional design of the INFOD Web Service Registry
Admin
Subscription Reasoning Component
Registry Manager Component
Association Manager
Vocabulary Manager
Subscription Manager
Publisher Manager
Consumer Manager
Subscriber Manager
Register, Deregister & Reregister
INFOD Registry Service
Recompute
GetMetadata 4

5. Simple Web services for testing
Some simple publisher, consumer and subscriber services
Each service implements the Notify interface:
Consumer: uses notify interface to receive messages from publisher
Publisher: uses notify interface to receive notification from registry about new or modified subscriptions and consumers
Subscriber: uses notify interface to receive notification from registry about modified subscriptions
Testing Client :
Act as factory for creating the publisher, consumer and subscriber services.
Verify that the requested (subset of) data from the publisher was received by right consumer according to subscription.
Monitoring of publishers and consumers through additional interface – GetCurrentData
For example, a publisher might be a temperature sensor and observe temperatures varying according to the formula:
Temperature = mean temperature + range * SIN( 2π t / P )
E.g. mean temperature = 20C, range = 15C, P = 200 sec., measurements are made every 10 sec.
A subscription could then be “send me temperature data from publisher ‘X’ when Temperature > 22C”. Or perhaps “tell me that it is ‘HOT’ when Temperature > 30C”.
The GetCurrentData interface would then return say:
ServiceName
CurrentDateTime
CurrentTemperature 5

6. Subscription processing component in the INFOD Registry
key part of the INFOD Registry
Upon changes to the entries in the Registry database, recompute dependencies and
Send the (changed?) subscription constraints and consumers to the appropriate publishers (that had requested to be notified).
Uses the Notify interface of the Publishers. 6

7. Subscription processing component in the INFOD Registry
Publisher Service(s)
Publisher Service
Consumer Service(s)
Consumer Service
Notify
Client
Create & Monitor
INFOD Registry Service
Subscription Reasoning Component
Registry Manager Component
Subscriber Service(s)
Subscriber Service
Create
Test Environment 7

8. Phased development Phase 1
Simplest scenario with a known data vocabulary and a trivial subscription:
1 known data vocabulary, so no need to add it to the INFOD Registry.
1 Publisher service added to the INFOD Registry.
1 Consumer service added to the INFOD Registry (which also doubles as the Subscriber service).
1 simple subscription with just data constraints and no property constraints.
Hence evaluation of the subscription by the INFOD Registry is trivial.
the WSN Notify interface is not implemented, but instead each software development group is free to use whatever in-house “notify” mechanism that they are most comfortable with (e.g. JMS).
very simple data is published by the publisher.
the Client should then monitor the data values available at the publisher and the (modified/filtered) data being received by the clients. 8

9. Phased development Phase 2 As for Phase 1, but now including:
2 Publisher services.
2 Consumer services (which again double as Subscribers).
The addition of Property vocabularies and instances of these properties for the publishers and consumers.
A subscription which now contains some simple property constraints as well as data constraints.
Evaluation of the subscription by the INFOD Registry should still be made easy
The Client should now be able to monitor the different data values being received by the different consumers and can compare it with the data that was originally generated by the publishers. 9

10. Phased development Phase 3 As for Phase 2, but now including:
Multiple data vocabularies.
Multiple Publisher services added to the Registry.
Multiple Consumer services added to the Registry.
Multiple Subscriber services added to the Registry.
More complex subscriptions with data constraints and property constraints.
More complex data is published by the publishers. 10

11. Phased development Phase 4 As for Phase 3, but now including:
A standard notification interface such as WSN Notify.
Phase 5?
As for Phase 4, but now including:
Security??? 11