WebFlow: Web Interface for Computational Modules

3/27/99


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Table of Contents

WebFlow: Web Interface for Computational Modules

Authors

Agenda

Part I

WebFlow Mission

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Seamless Access

Examples:

Example: Globus

Towards a complete solution ...

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Target Architecture

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Example of a custom GUI: LMS Front-End

PSE Example: CCM IPSE

QS Front End

Part II

Implementation Strategy

Java Grande: DATORR Desktop Access to Remote Resources

WebFlow design

A few words about CORBA

Distributed objects

How is this possible?

Example of IDL definition

We need more flexibility...

Event binding

Controlling a module

Adding a remote module

Back to WebFlow design

WebFlow Server

WebFlow Server

CORBA Based Middle-Tier

WebFlow Context Hierarchy

Gatekeeper

Middle-Tier modules serve as proxies of Back-End Services

Modules

Services

Example of a proxy module

WebFlow over Globus

Part III

Secure Access: terminology

Secure Access

Security Model

Distributed Objects are less secure

CORBA security is built into ORB

Authentication

Privilege Delegation

CORBA access model

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Part IV

Applications vary by the functionality of their Front-Ends

Applications vary by how they are composed from modules

The modules can interact with each other in different ways:

Applications vary on how the Front-End interacts with the Middle-Tier

Landscape Management System

LMS Objectives

LMS: Changes in Vegetation

LMS: Changes in Vegetation

LMS Front End

Data Retrieval

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WMS based Visualizations

Implementation of LMS

Running LMS

To run LMS

Client code

1.start runCasc2d;

2. casc2 starts in a new thread, uploads data to its web server and sends “done” event to Edys;

3. casc2 waits for new data from Edys; Edys downloads data and runs ‘till the first rain event

4. casc2 waits for data; Edys uploads data, sends event “done” and quits

5. runcasc2 fetches data from remote web server

6. Casc2d detects new data and resumes execution

7. Casc2d completes the rain event and writes new data; runCasc2d detects new data and sends event to Edys

8. Edys fetches data from the remote web server and starts; casc2d waits for new data

9. This cycle is repeated ‘till all rain events are processed

10. Casc2d quits, final run of Edys begins

11. Edys terminates. All data are on the WinNT side and can be visualized using WMS tools.

Quantum Simulations

Quantum Simulations

QS: WebFlow implementation

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Implementation of QS

QS: Front-End

Building an application

Document Type Definition

Example XML document

Object Oriented Applications

Mobility System’s Applications

Building an application

IPSE/Gateway Project

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Multi-tier Architecture of Gateway

Starting Gateway

Initialization of a session

Middle-Tier is given by a mesh of WebFlow Servers that manage and coordinate distributed computation

Summary of features

How to use WebFlow

How to install

Updates

How to write a WebFlow module

Write IDL definition

Compile usig jidl --tie

Implement the interfaces

Compile everything (javac)

Add modules to config files

Add modules to config files

Simple Client

runCasc2dImp

runEdysImp

Updates

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Author: haupt

Email: gcf@npac.syr.edu

Home Page: http://www.npac.syr.edu