LEAD Portal: a TeraGrid
Gateway and Application
Service Architecture
Marcus Christie
Indiana University
LEAD Project
(http://www.leadproject.org)
Overview
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Introduce LEAD
LEAD Portal
TeraGrid Science Gateways
PURSe
Miscellaneous
Linked Environments for Atmospheric Discovery
Linked Environments for Atmospheric Discovery
The LEAD Goal
Provide the IT necessary to allow
People (scientists, students, operational
practitioners)
and
Technologies (models, sensors, data
mining)
TO INTERACT WITH WEATHER
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Example: “Optimal” Weather
Prediction Using Dynamic Adaptivity
Storms Forming
Forecast Model
Streaming
Observations
Data Mining
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On-Demand
Grid Computing
LEAD Strategy
• Take a “data first” approach
– Allow users to bring data into LEAD system
– Searchable data
• Web access to important tools
– Users can search for data, run codes using
portlets
– Java WebStart (one-click install) when more
advanced interface needed
• Service Oriented Architecture (SOA)
– Virtualize access to resources (data,
computational resources, software)
• Provide workflow tools
– Users log into portal to create new workflows
which combine the execution of community codes
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Executing the workflow
Experiment
Builder
Portlet
2. GPEL starts executing
by locating application services
and sending them requests.
1. Launch XBaya
as workflow
listener
XBaya
Workflow
Monitor
GPEL
Engine
GFac
Application
Factory
Application
Service Application
Service
MyLEAD
Metadata
Catalog
MyLEAD
Agent
Application
Service
3. Services and GPEL send notifications about
workflow progress to the broker who logs them
with the MyLEAD agent and the Monitor.
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AtmosphericBroker
Discovery
Notification
Where does the portal fit in?
• Interfaces to the SOA
• Provides a low barrier to entry so as to
attract a larger community of users
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What is the LEAD Portal?
• Techologies
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GridSphere
OGCE
Velocity and JSF (MyFaces) portlets
Apache (2.2.x) + mod_proxy_ajp + Tomcat (5.5.x)
• Architecture
– Portal is a service client
– 2 layers between portal and grid services
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portal.leadproject.org
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Data Tools
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Data Tools
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Workflow Tools
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Workflow Tools
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Where do these workflows run?
• Well, we have our own modest testbed
in the LEAD project.
• For serious forecast runs, however, we
use TeraGrid.
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TeraGrid Science Gateways
• Engage non-traditional community of
users (bring in users who don’t have the
know-how to make WRF runs)
• Provide community-specific interfaces
to TeraGrid resources
• Community accounts, allocations
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Security Requirements
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Validating inputs
Audit each user’s action
Administrative user shut off
Logs
Accounting information – quotas and
reporting
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TeraGrid Accounting
• Application services send notification
message with job information
• Accounting service listens for, collects
information
• Later, on a periodic basis, query the TeraGrid
accounting database for usage information
• Store into local database organized around
workflows -> jobs
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PURSe Portlets
• PURSe – Portal-Based User Registration
System
– Wraps MyProxy and simpleCA
– Provides a simple API that can be used by a web
application
• 1.0 PURSe Portlets released on May 11,
2006
• JSF, MyFaces (1.0.9) based
• http://www.extreme.indiana.edu/portals/purse
-portlets
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Portal Users
• Need an Identity Certificate
• Using PURSe Portlets
• Authenticates user to capability based
authorization framework
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Getting an Identity Certificate
• Portal Account
• Identity Certificate
• MyLEAD Personal
Data Repository
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PURSe Portlet Registration
Module
• Interface org.ogce.purse.api.RegistrationModule
• Implement onEvent(PurseEvent e) {};
• Events:
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Registered
Confirmed
Accepted
Password Update
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Capabilities
• User must have requisite capability
tokens to run applications
• Capability tokens are digitally signed
policy documents that contain
assertions about who can do what
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A Tale of Two Authorization
Systems
Capabilities
GSI
Application
Service
Portal
- send cap token
- identity
certificate
TeraGrid
- community
account
- proxy
certificate
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Miscellaneous
• AJAX + JSF to create rich components
– graceful degradation is important
– dealing with service oriented latencies is would be
a big win
• Share JSF components?
• Portlets without a portal
• How to bring “Web 2.0” methodologies to grid
portals?
– Ideal is a wiki; portlets brought in with special wiki
markup
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