Dragon: Soft Real-Time Event Delivering Architecture

for Networked Sensors and Appliances

Masayuki Iwai, Jin Nakazawa,

Hideyuki TokudaKeio Univ. Japan

14/Dec/2000

Outline Scenario Implementation Details of Dragon

Three typical services Soft real time event delivery

Related work Summary

Entrance light

room TVEntrance door

room air conditioner

room light

thermometer

Scenario: Smart Entrance

User detector

Scenario: Smart EntranceIf(temperature<low)

If(detect the user)Entrance light on

TV switch on

Entrance door Unlock

room air conditioner On

room light on

thermometer

User detector

Scenario: Smart Entrance

We implemented Dragon aimed at

Developers can easily program distributed system-ready devices

Users of the system can construct flexible event-driven systems visually

Users can also set timing constraints for each event path

RMI+JVMTCP/IP

PCs

RMI+JVMTCP/IP

Embedded Computer

RMI+JVMTCP/IP

Embedded Computer

Jini LUS Jini Clients Jini Services

Assumption

Dragon

Event Binding Editor

sensorsappliances

user 　

Event Binding Editor User can

show every service that is running on the distributed devices

Users just wire the event path between the distributed services

Typical services

Event Supplier and Consumer

Sensing Module (Real World)

Event Output Module

Acting Module(Real World)

Event Input Module

event

Event Manager

Event Output Module

Event Input Module

Event Filtering Module

Event Registration/Firing

register

notify

Event Supplier Event Manager

Event Consumer

ES

EM

EC

sense

actionEM.EIM.notify(event_obj);

EC.EIM.notify(event_obj);

Event Object

Event delivery

NotifyNRTOT Non Real-Time Ordering Table

Normal Event Delivery

NRTOT

EC1

EC1stub

EC2EC2stu

b

EC3EC3stu

b

EC4

EC4stub

Event Filtering ModuleEC5stu

b

EC5

Copy

Copy

Copy

Copy

Copy

Event ObjectEvent Consumers

Event Manager Service

EC1

EC2

EC3

EC4

RTOT Real-Time Ordering Table

Soft Real Time Event Delivery

NRTOT

EC1stubEC2stubEC3stub

11

Event Filtering Module

11 11 1111

EC5

Copy

Copy

Copy

Copy

Copy

EC4stubEC5stub

RTOT

Event Object

22 22 22 2222

11

11

11

11

11

Copy

11

11

11

11

11

22

Copy

22

Copy

22

Copy 22

Copy

22

Notify

Event Manager Service

EC1

EC2

EC3

EC4

RTOT Real-Time Ordering Table

Soft Real Time Event Delivery

NRTOT

EC1stubEC2stubEC3stub

Event Filtering Module

44 33 22 1155

EC5

Copy

Copy

EC4stubEC5stub

RTOT

Event Object

11

1111

11

Skip

55 44 33 2266

Copy

22

Copy

2222

22

Skip

66 55 44 3377

Copy

33

Copy

33

Notify

Event Manager Service

Soft Timing Analysis

Related Work ECJ (toshiba) JECho (Georgia) Carp@ CORBA Event Service (OMG) HAVi Event Service(HAVi org) Java Spaces(Sun)

Summary Dragon

Developers of the devices can program distributed system easily using Dragon API

Users can setup ah-hoc distributed systems easily by using the Event Binding Editor

User can set timing constraints for event deliveryusing Even Binding Editor

Future work Inside event object data description

XML, Java Byte Code, any.. Event loop /dead lock avoidance Adaptation to CORBA Event Service