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A Portlet Interface for
Computational Electromagnetics
on the Grid
Maria Lin and David Walker
Cardiff University
Project Collaborators
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Cardiff University
Swansea University
BAE Systems
HP
Singapore Institute of HPC
Outline
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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
BAE SYSTEMS
Create
geometry
UWS
Geometry data
Output
Mesh
Generate mesh
Output
Output
WeSC
CEM simulation
Other locations
GECEM Production Grid
UWS
BAE SYSTEMS
Geometry data
Create
geometry
Output
Mesh
Generate mesh
Output
Output
Singapore
CEM simulation
Other locations
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
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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
Geometry data
Surface Mesh service
Geometry Archive
Surface Mesh Archive
Volume Mesh Service
Volume mesh archive
CEM Solver Service
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
MyProxy
Server
Surface Mesh
Service
Volume Mesh
Service
GECEM portal
CEM Solver
Service
Archives
Use Case
BAE
Swansea
Geometry
Data files
Mesh Service
WeSC
Meshes
Solver control
files
Solver Output
Migrate Solver
Service
Solver
Current Version
• Use Gridsphere 2.0.2 as the portletbased 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