Collaboration Systems

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Collaboration Systems
Prasun Dewan
Department of Computer Science University of
North Carolina CB 3175 Sitterson Hall Chapel
Hill, NC 27599-3175 dewan_at_cs.unc.edu http/www.c
s.unc.edu/dewan
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Issues

• Advanced?
• Writing
• Integrated with 291
• Programming
• Careful Vs Bulk
• Combined with 243
• Presentation
• Pick a Project Quickly
• Nature of Area
• Look at Web Page

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Overview

• Why Collaborative Applications?
• Related Areas
• Nature of System Support
• Concrete Examples
• Lessons

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Benefits Towards Being There
Face-to-Face
Interaction
Computer-Supported
Interaction
Network
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Gesture Cam Remote Surrogate
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Benefits Beyond Being There
Face-to-Face
Hollan Stornetta 92
Interaction
Computer-Supported
Interaction
Network
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Action Workflow
Status By Candidate Workflow Step
Manage Review
Manager
Director
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Dual Collaboration Goals

• Towards Being There
• Beyond Being There

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Collaboration Vs Virtual Environments
VE
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Collaboration Vs Real-Time Distributed Apps.
Collaborative Applications
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Collaboration Vs Mobile Apps.
Mobile Applications
Collaborative Applications
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Relationship with Object-Oriented and User
Interface- Technology
Interactive Applications
O-O Applications
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System Support
Applications
Windows Apps
Competing Systems
Interoperability
Extensibility/Composability
Applications
Distribution
Performance/Resource Management
Functionality
Coupling
System Support
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System Support
Applications
Existing
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
X, Windows, Java Apps.
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Shared Window System
Application
Tightly-Coupled Meetings
Easy to Understand
Application-Independent
Automatable
Window
Window
WYSIWIS
Coupling
Audio/Video
User 1
User 2
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Centralized Architecture
XTV (88) VConf (87) Rapport (88) NetMeeting
X Client
Pseudo Server
Pseudo Server
X Server
X Server
User 1
User 2
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Shared Window System
Application
- Scroll Wars
Tightly-Coupled Meetings
- Window Wars
Easy to Understand
- No Flexibility
Application-Independent
- Performance
Automatable
- Consistency
Window
Window
WYSIWIS
Coupling
Audio/Video
User 1
User 2
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System Support
Applications
Existing
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
X, Windows, Java Apps.
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
Beyond WYSIWIS
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Flexible Model of Collaboration
Application
Window Version 1
Window Version 1
User 1
User 2
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
Coupling, Merging, Diffing, Undo, User Interface,
Security, Concurrency Control
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
Distributed Architecture, Jitter Latency Control
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XTV Centralized Architecture
X Client
X Server
X Server
X Server
X Server
User 1
User 2
User 3
User 4
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Migration
X Client
Pseudo Server
Pseudo Server
Pseudo Server
X Server
X Server
X Server
User 2
User 3
User 4
Laptop
Handheld
Handheld
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Migration
X Client
Pseudo Server
Pseudo Server
X Server
X Server
User 3
User 4
Handheld
Handheld
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Centralized - Replicated
X Client
X Client
Pseudo Server
Pseudo Server
X Server
X Server
User 3
User 4
Handheld
Handheld
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Replication - Centralized
X Client
Pseudo Server
Pseudo Server
Pseudo Server
Pseudo Server
X Server
X Server
X Server
X Server
User 1
User 2
User 3
User 4
Laptop
Laptop
Handheld
Handheld
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
Distributed Architecture, Jitter Latency Control
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
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Monolithic System

Suite
Pseudo Server
Shared Windows
Merging
Logging
Coupling
Replication
User-Interface
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Component-based System

Suite
Pseudo Server
Shared Windows
Merging
Logging
Coupling
Replication
User-Interface
Logging
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Composability

• A logging service can dynamically compose with
  different instances of a client.
• A client can dynamically compose with different
  instances of a server.

Logging Service
XTV 1
XTV 2
Logging Service
XTV
Logging Service
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Genericity

• A logger can compose with different loggables at
  different levels of abstraction.

XTV
Logging Service
Suite
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Generic API
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Ease of Programming
X Client
XTV
X UI Protocol
Specialized Logging Service
Other Services
X UI Protocol
X Servers
(a) XTV Implementing Latecomer Service
X Client
XTV
X UI Protocol
Generic Logging Service
Other Services
X UI Protocol
X Servers
(b) XTV Using Logger for Latecomer Service
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Connection Bus
Pseudo Server

Suite
Shared Windows
Merging
Logging
Coupling
Replication
User-Interface
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Proxy Support
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
Generic Interfaces, Design Patterns, Connection
Managers
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
Coupling, Concurrency Control, Merging, Access
Control
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Interoperation
Inter-operation
Our Organizations Collaborative Spreadsheet
Your Organizations Collaborative Spreadsheet
User 1
User 2
User 3
User 4
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Interoperation Example
Habanero Spreadsheet
Custom Spreadsheet
Flexible Coupler
User 1
User 2
User 3
User 4
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Interoperating Coupling
Dynamic Composition
Local Semantics Preserved
Spreadsheet Model
WYSIWIS Coupler
Flexible Coupler
Spreadsheet Replica
Spreadsheet View
Spreadsheet View
Spreadsheet Replica
User 1
User 2
User 3
User 4
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
Coupling, Concurrency Control, Merging, Access
Control
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System Support
Applications
Interoperability
Extensibility/Composability
Applications
Performance/Resource Management
Functionality
System Support
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Lessons

• Being there

• NetMeeting, Shared whiteboards,
  video-conferencing successful

• Communication
• Software Inspection Review
• Control
• Workflow

• Beyond Being there

Flexibility Needed
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Life Cycle

• Requirements
• Design
• Programming
• Debugging
• Testing
• Review
• Maintenance

Integration of Sync and Async
Integration of Life Cycle Steps
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Lessons

• Flexibility
• New area explored faster
• Training needed
• Exploratory Environment
• How to see effects on other users
• textual descriptions
• animations
• network simulations?

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Lessons

• Infrastructure
• XTV
• Suite
• Rendezvous Constraint-based languages
• Lotus Notes
• GroupKit
• Java Enterprise Beans
• Java Shared Data API

• Make different tradeoffs

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Favoring Automation/Reusability
XTV
Programmer
User
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Favoring Performance/Flexibility
Suite
Programmer
User
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Lessons

• Reuse Importance

• NetMeeting, X

• Flexibility Importance

• Shared Whiteboards, Chat, Lotus Notes

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Composibility of Generic Interfaces is Useful
Generic User Interface
Access Control
Spreadsheet
Bus Agent
Coupler
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Usefulness of Interoperation?
Inter-operation
Our Organizations Collaborative Spreadsheet
Your Organizations Collaborative Spreadsheet
User 1
User 2
User 3
User 4
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Composition, Interoperation Related
Habanero Spreadsheet
Bus Spreadsheet
Interoperation uses Composition
Interoperation example
Specific Logging Client
Generic Logging Server
Composition Uses Interoperation
Composition Example
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Java Experience

• Portability
• Introspection Support
• Interfaces
• JSDA
• Swing
• RMI
• Version Evolution
• Existing Colab Systems
• Powerful but slow!

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Lessons

• Infrastructure is Important
• ICICLE built from scratch
• CIS, CAIS built using Suite

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Combining Benefits
Server
Client
Bean Approach
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Composition and Interoperation Related
Bus Spreadsheet
Habanero Spreadsheet
Interoperation Example
Specific Logging Client
Generic Logging Server
Composition Example
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Concurrency Control Policy 1
FloorControlSystem
User 1
User 2
False User 3
LockConrolSystem
User 4
User 5
User 6
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Concurrency Control Policy 2
LockControlSystem
False User 1
User 2
User 3
FloorConrolSystem
User 4
User 5
User 6
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Proxies