1. O2S Components Framework
Day 1, Session 1, Part 3
July 2006
Quanta JustPlay Seminar
Justin Mazzola Paluska

2. Acknowledgements
The O2S Components Framework is mostly the work of the Hubert Pham so he should get all of the credit for its implementation.
These slides are derived from Hubert's slides.

3. Contents
Motivation
Objective
Approach
Model

4. Motivation Planner: high level goal  plan
O2S Component Framework: plan  actualize

5. Motivation
Developing asynchronous, distributed software is (still) painful:
slow performance
adaptiveness is difficult
stubs (distributed objects)
hard to debug failures!

6. Motivation
Traditional distributed applications: logic intertwined with implementation

7. Objective
A distributed software component framework that optimizes for:
Simplicity
Construction API and Environment
Debugging
Adaptiveness
Performance
Platform and Language Independence

8. Approach

9. Approach

10. Approach

11. Approach
Construct applications by instantiating distributed components and interconnecting them together: circuit diagram model
Monitor and debug by processing serial messages from implementation

12. Approach Generic Components on a variety of platforms
Data Streams using a variety of protocols

13. Approach Synchronous Simple Environment Adaptable
Language and Platform Independent
Asynchronous
Parallel
Low Performance Overhead

14. Approach: Example def setup_voice_rec():
voice_rec = system.lookup("Voice Recognizer",
grammar = "voice_shell")
event_queue = system.get_event_queue(handler =
handle_event)
voice_rec.set_recognition_target(event_queue)
voice_rec_input = voice_rec.get_audio_sink()
mic = hand_held_device.get_mic()
system.connect(voice_rec_input, mic)
def handle_event(new_event):
if new_event.recognized_token == "Hello":

15. O2S Model Synchronous Simple Environment Adaptable
Language and Platform Independent
Asynchronous
Parallel
Low Performance Overhead

16. O2S Stack The O2S Stack establishes the Control Environment
Properties:
Many implementation technologies available for every layer
Each layer depends only upon the abstractions established by the layer immediately beneath
Can swap out any implementation for another

17. Transport Low level RPC and wire encoding for basic primitives.
A Few Known Implementations:
XML-RPC
SOAP
Sun RPC
O2S uses off-the-shelf XML-RPC

18. Network Object
Provides network object packaging; transparency in passing and receiving references to remote objects; data serialization and marshaling.
Some Implementations:
Sun Java RMI
OMG Corba
O2S NPOP

19. O2S NPOP Network Portable Object Packaging
Language and Platform Independent
Pass object references between methods, processes, and hosts
Automatic Stub Generation
Object Interning and Reference Tracking
Named by a URI to an XML specification

20. O2S NPOP

21. System Management Provides “host-level” abstractions and services:
health monitoring
event messaging
directory services for
network object discovery

22. System Management A Few Implementations: Sun Jini (uses RMI); JXTA
UPnP
IETF Service Location Protocol
O2S Architecture

23. O2S Architecture Entity host management
runtime environment for remote objects
Registry
health monitoring + subscription/notification
(bootstrap) directory services
Event / Message Passing

24. O2S Architecture
Health Notification
Subscription

25. Component Structuring
Provides a framework for constructing, interconnecting, bundling (abstracting), and hotswapping sets of distributed modules.
Some Implementations:
Weaves [Gorlick91]
O2S Components
In SVN HEAD, but not in the current snapshot

26. O2S Model Synchronous Simple Environment Adaptable
Language and Platform Independent
Asynchronous
Parallel
Low Performance Overhead

27. Implementation Environment
Plaforms
MS Windows
GNU/Linux
Apple OS X – PowerPC and x86
Devices
HP iPAQ
Nokia Mobile Phones
GumStix

28. Implementation Environment
Low-Level Networking Protocols
TCP Sockets
Bluetooth
UDP Datagrams (SVN HEAD)
RTP (Soon!)

29. Implementation Environment
Languages
Python
Java, C
External Interfaces
X10 home automation
Galaxy VR & Flite TTS
SIP VoIP + Asterisk (Soon!)
AOL Instant Messenger

30. Questions? Day 1, Session 1, Part 3 July 2006 Quanta JustPlay Seminar
Justin Mazzola Paluska