GroupGraph: a collaborative hierarchical graph editor based on the Internet

1
GroupGraph a collaborative hierarchical graph
editor based on the Internet

• Helio A. Souza Lima Filho
• Celso M. Hirata

2
Requirements

• Development of a graph editor tool
• hierarchical graph
• allows the collaborative work
• based on the Internet
• portability

3
Outline

• Modeling, collaborative work, infrastructure
• Editor components
• Restriction model, lock, perception mechanisms,
  communication model
• Case Studies
• Final Comments

4
Modeling

• Model it is a simplified representation of the
  system being studied, it includes only the
  relevant aspects regarding the goal of the study.
• Techniques that use graphs
• Activity Cycle Diagrams (ACD)
• Petri nets
• Automata

5
Infrastructure Internet

• Various hosts that share neither memory nor clock
• Each computer owns its own memory and operating
  system
• Communication by message-passing
• Issues resource sharing, scalability,
  reliability, availability, performance, and
  security.

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Java and Java RMI

• Characteristics
• Object Oriented
• Security
• Portability
• Java Platform JVM e API.

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Distributed Shared Data

• There are two basic mechanisms replication and
  migration.
• Issues are transparency, ease of programming,
  scalability and performance.
• We use the concept of total replication and no
  migration.

8
Groupware

• CSCW (Computer Supported Cooperative Work)
  studies and tries to understand how people work
  together (both with and without groupware), and
  how the computer and related technologies can be
  designed to support effective collaborations.
• One of the goals of these studies is to construct
  computer systems to allow cooperative work.
• Real time groupware allows two or more
  geographically separated people to work together
  at the same time through a computerized
  environment.

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Editor Components

• Server keeps the a copy of the graph controls
  the synchronization among clients.
• Client owns a copy of the graph interacts with
  the user.
• Model of Restrictions define as the properties
  for graph editing.

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Model of restriction

• Allows to configure the graph editor.
• Node selection.
• Properties of the nodes.
• Properties of the edges.

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Global Properties

• Allows the visualization of the restriction model.

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Properties

• Exhibit the properties of the node or edge.

13
Lock mechanism

• To lock it is necessary to select first.
• Node and edge can be selected
• In the current implementation, the lock is for
  the composite node

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Perception Mechanisms

• Chat

Telepointers
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Communication between the client and server
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Case Study 1 Petri net representation of the
dinning philosophers
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The Petri net representation the restriction
model
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The dinning philosophers editing
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Case Study 2 Interconnection network of switches
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Interconnection network ACD representation of
the switch
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Interconnection network model
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Interconnection network sub-model
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Final Comments and Conclusions

• Some limitations of the tool
• Locking mechanism
• Number of users
• Security
• Fault tolerance

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Related Work

• GroupSim software for collaborative discrete
  event simulation based on the WWW.
• GroupPlaces architecture for groupware based on
  the WWW.
• Graph editors
• Graph Editing Framework (GEF).
• aiSee software for graph visualization.

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Future Work

• Integrate with a DBMS
• Integrate with other tools such as software
  generation and analyzers
• Support to other types of specifications such as
  UML
• More elaborated tools for cooperative work