Table of Contents
WebFlow: Web Interface for Computational Modules March 99 CEWES
Authors
Agenda
Part I
WebFlow Mission
Seamless Access
Seamless Access
Examples:
Example: Globus
Towards a complete solution ...
We need a third tier!
Target Architecture
WebFlow Choices
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
CORBA ORB Using Akenti
Part IV
Application Front ends
Application Module Structure
Module Interaction
Front End Middle Tier linkage
Landscape Management System
LMS Objectives
LMS: Changes in Vegetation
LMS: Changes in Vegetation
LMS Front End
Data Retrieval
LMS Launching on Multiple Back Ends
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
Typical QS WebFlow Session
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
3 Tier Architecture
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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