Holding slide prior to starting show

A Portlet Interface for Computational Electromagnetics

on the Grid

Maria Lin and David Walker

Cardiff University

Project Collaborators

• Cardiff University

• Swansea University

• BAE Systems

• HP

• Singapore Institute of HPC

Outline

• Project Overview and Challenges

• Design

• Gecem Portal and Portlets

• Portal and Security

• Use Case

• Future Work

• Conclusion

Project Objective

• Develop a user-friendly environment for users to integrate mesh generation, large-scale linear system solver, and collaborative visualization within a Web service framework.

• Problem domain is computational electromagnetics

GECEM Prototype Grid

Geometry dataUWS

WeSC

Other locations

BAE SYSTEMS

Create geometry

Generate mesh

CEM simulation

MeshOutput Output

Output

GECEM Production Grid

Other locations

Geometry dataUWS

Singapore

BAE SYSTEMS

Create geometry

Generate mesh

CEM simulation

MeshOutput Output

Output

Challenges

• Resources are intrinsically distributed– No sharing of software and hardware– Sharing data

• Requirements– Single logon to multiple machines– A user friendly interface– Secure environment– Support Multi-user

Previous Work

• Use a shell-script to call Global Toolkit 2.0

• User account handling is complex

• Not user-friendly

Current Approach

• Use a portlet approach

• Use GridSphere Portal framework

• Use portlet service models provided by GridPortlets

• Create GECEM portlets to locate input files and services and to submit jobs

Portlet Design

• Programmed in Java • User-interface component• Handles user requests and generates

dynamic content in the form of markup fragments that can be aggregated with other fragments to form a portal page

• A portlet is a window to provide a specific service

• Easy to customize for individual users or groups of users

Portlets

• Visible active components users see within their portal pages

• Java servlet inside a portal

• A special type of servlets– The Portlet API extends and subclasses

the Servlet API

GridSphere

• Provide a portlet container• Provide user management, session

management, and group management• Provide support for role-based access

control• Provide portlet subscription• Provide layout selection• Allow third-party portlet

Grid Portlets

• Resource Browser Portlet – Resource Registry

• Credential Retrieval Portlet– Credential Management uses credential

repository to store user credentials

• Provide File Browser Portlet• Easy to use for invoking OGSA Reliable

File Transfer (RFT) Service

GECEM portlets

• Select machine for mesh services and solver service

• Select geometry file from a list of machines

• Invoke OGSA grid service for job submission

GECEM Portal

• Supports surface mesh generation

• Supports volume mesh generation

• Supports CEM solver migration

• Supports collaborative visualisation and analysis

Aspects

• Accessbility of CEM solver codes– High quality– Significant investments of time and money– Owner may not want to install codes

permanently on computers outside of their organisation

CEM solver service

• Support migration of codes to a target machine

• execute

• Send output to solution archive

• Delete codes and data sets

Workflow

Surface Mesh service

Volume Mesh Service

CEM Solver Service

Geometry data Geometry Archive

Surface Mesh Archive

Volume mesh archive

Solution archive

Solution data

Portal and Security

• Based on Globus Security Infrastructure for authentication

• Provides single sign-on– Use grid credentials– Use proxy certificate – Use MyProxy Credential Repository– Use MyProxy Upload Tool

Logon using MyProxy

• User upload their credential to a MyProxy Server

• User Logon the Gecem Portal using the MyProxy username and passphrase

• Login Portlet retrieves the credential from the MyProxy Server and creates a credential mapping for the user

• GridPortlet stores the credential into a credential repository

Design

GECEM portal

CEM Solver Service

Volume Mesh Service

Surface Mesh Service

Archives

MyProxyServer

Use Case

Mesh ServiceGeometryData files

Meshes

Solver control files Migrate Solver

Service

BAE Swansea WeSC

Solver Output

Solver

Current Version

• Use Gridsphere 2.0.2 as the portlet-based portal

• Use Gridportlets (cvs version)

Software• Prerequisite Software

– Java 2 Standard Edition version 1.4.2 or higher. 

– Tomcat 4.1.31– Apache Ant version 1.6.2 – Globus Toolkit (GT3.2.1)

Related Work

• Geodise toolkit

• P-GRADE

• GEMLCA

Work In Progress

• Archiving results

• Use UDDI for service discovery

• Apply RAVE for visualization

Future Work

• Use workflow model

• Adapt our framework to WSRF

• Extend GECEM grid to include all project partners

Conclusion

• Portal provides a high-level user interface for scientists to access distributed resources easily

• Portal hides away the complexity of using grid

• User can access the portal anywhere