Holding slide prior to starting show

A Grid-based Problem Solving Environment for GECEM

Maria Lin and David Walker Cardiff University

Yu Chen and Jason JonesSwansea University

Project Collaborators

• Cardiff University

• Swansea University

• BAE Systems

• HP

• Singapore Institute of HPC

Outline

• Project Overview and Challenges

• Design

• Gecem Portal and Portlets, and Grid Services

• 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

Resources

Data Meshers Solvers

Geometry Files

BAES

Code

Swansea

Code

Swansea

Challenges

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

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

Open Grid Service Architecture (OGSA) Grid Services

• Provide GSI security

• Provide Lifecycle Management

• Provide state information– Service data elements

• Gridftp for file transfer

Why Grid-based?

• Advantages– Support resource sharing– Uniform access to resources

• Limitation– Complex to use– Low-level

Design

• Use portal and portlets to provide end-user interfaces for using grid services

• Use MyProxy as single log-on• Use URI and GridFTP to locate input

files • Develop OGSA Grid Services for mesh

generation and solver migration• Use UDDI to discover services

Portals and Portlets

• Portal – Aggregate and integrate portlets

• Portlets– Individual window applications that provide

content for a portal– Easily customised 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

Gecem Portal - Overview

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 and GridFTP Browser Service

Resource Registry

• Hand-written XML registry

• Consists a list of machines and the services provided by these

• Define the machine provides– Myproxy – grid-ftp– gram

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

Gecem Portlets - Functional

• Meshing Portlet

• Migrate Solver Portlet

GECEM Portlets - Instance

• File Selection Portlet

• File Parameter Portlet

• UDDI Portlet

• Grid Service Portlet to invoke meshes and solvers simulation

Meshing Portlet - Options

Migrate Solver - Options

Grid Services

• Legacy codes– Complex, high-quality

• Develop OGSA compliant grid services– Meshing Grid Service– Migrate App Grid Service

Portlet to invoke Grid Service

File Browser Portlet(select local files)

File Parameters Portlet(display URI of files)

UDDI Portlet (select service) Invoke Grid Service

Files

GSH

Files

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)

Future Work

• Archiving results

• Use workflow model

• Apply RAVE for visualization

• 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