Object Web Architecture
Portals P2P XML
Euresco Conference at Castelvecchio Pascoli Italy June 16-21 2001
EuroConference on Problem-Solving Environments for Numerical Mathematics, Science and Engineering Applications
Geoffrey Fox
IPCRES Laboratory for Grid Technology Computer Science, Informatics, Physics
Indiana University Bloomington IN
Distributed Objects
• Examples of current object technologies
– Documents -- URL
– "General Programs including database invocations"
• Old Style Web -- CGI
• New Style Web -- XML
• CORBA and COM -- special "interface definition
language" (IDL) defines invocation in C++ like syntax
• RMI uses Java language as IDL language
• Benefits of distributed objects
– allows objects written in different languages to communicate seamlessly via standardized messaging protocols embodied by middleware.
– Higher levels of transparency of interoperability
– Objects can be “self-managing” of resources
– provides flexible grain of decomposition for building complex systems
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Distributed Object Web Technology Model
• Basic Vision: Merge Web and Distributed Objects
• E.g. Need to abstract entities (Web Pages, database entries, simulations) and services as objects with methods(interfaces)
– CORBA .. XML is “just” CGI done right
• COM(Microsoft) and CORBA(world) are competing cross platform and language object technologies
• Javabeans plus RMI and perhaps JINI is 100% pure Java distributed object technology
• W3C says you should use XML which defines a better
IDL and with Schema an object specification model and
3-Tier Architecture and Different Object Models
• There are several important Object Models: COM, CORBA, Java, Web, Oracle Database ……
• But it doesn’t matter!!
Database
XM File Syste (Web Site) Or
Middle Tie “Business Logic
dissociate User and Back
End
Export/Import
Request
Information
Objec Repository
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Clients an their servers
Middle Tier Custom Servers
Back En
Servers and their
services
Data base Matrix Solver Optimiza tio Service MPP MPP Parallel D Proxy NEOS Contro Optimizat ion Origin 200 Proxy NetSol v Linear Alg Server
Computational Science Grid: Multi-Server Web Computing System
IBM SP Proxy Portal Control Agent-base Choice o Compute Engine Multidisciplinar Control (WebFlow) Data Analysi Server Portals The Grid Portals are user Interfaces to a Gri The World Wide Web is a big Grid P2P Networks include Grids
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Computational Grids
• Exploit the analogy with electricity – make using a computer as natural as plugging an appliance (PDA, PC) into a wall socket
• Make the ensemble of computers, storage devices, scientific instruments on the web “seamlessly accessible”
• Link components of the grid together to solve a single problem
– Clusters, metacomputers
• There are computational grids, education grids, information grids, shopping grids etc.
– The web is a (information) grid
• Everything is an object
• Generic access implies standards for API’s and protocols
and services
• USC (ISI Carl Kesselmann) and Argonne (Ian Foster) pioneered grids
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Issues for Grids and hence Portals
• Are the grid components pretty much fixed – such as giant ASCI supercomputers
• Are they fleeting and mobile such as internet connected cell phones
– The set of IP enabled home sensors, appliances and controllers is a grid
• What are requirements?
– anonymity, performance Security,, ease of use …
• Different components and requirements implies that not likely to be just one grid but a federation of
interoperable grids
• What are the “standards” and who sets them
Foster’s Grid architecture
• What is difference between protocol (SOAP, HTTP) and
Application interface (HTML, MIME)
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ASCI Grid
•
Link the multi teraflop computers of ASCI
IPG Architecture
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Experimental Particle Physics Grid
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Earthquake
Engineering
Grid
• Links
Experimental Facilities,
Commodity Portals are Web Interfaces for Consumers
Yahoo, NetCenter, Amazon.com, Ebay.com etc. are portals fo e-commerce, news etc.
We want to use these ideas in building computer interfaces
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……...
Hierarchy of Portals and Their
Technology
• Portal Building Tools andFrameworks (XML, iPlanet, Portlets, www.desktop.com) Enterprise Portals Generic Portals Information Services Compute Services Education an Training Portals Science Portals Generic Services Collaboration Universal Access Security ……. Databases ……. MathML etc Quizzes Grading ... Education Services Grid Services Visualization .. .
……...
Services in Any Grid Application
•
Security
•
Fault Tolerance
•
Object
Lookup and Registration
•
Object Persistence
and Database support
•
Event
and Transaction Services
•
Information Services
•
Collaboration
among users
– Teachers and Students (Centra)
– Market lead and Salespeople (WebeX)
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Further Services in Computational Grids
• Job Status
• File Services (as in NPACI Storage Resource Broker)
– Support (XML based) computational science specific metadata like MathML, XSIL
• Visualization
• Programming, Debugging, Performance Monitoring
• Application Integration (chaining services viewed as backend compute filters) can be called Workflow
• “Seamless Access” and integration of resources between different users/application domains
• Parameter Specification Service (get data from Web form into Fortran program wrapped as backend
object)
Learning Management Grid from DoD ADL
ADL= Advanced Distributed Learning
Learnin Server Conten t Server( s) External systems: HR, E-Commerce, ERP... Migrati onAdapt er Learning Server A PI Adapt
er Application
Properties of Educational Objects
• Metadata from IEEE and IMS
– Roughly Properties of educational objects thought of as “documents” (author, title …)
• Course Packaging from ADL and IMS
– How to form bigger (educational) objects from smaller objects
• Enterprise Properties from IMS
– Link to people (users) and organization databases
(rather incomplete at present but must be important as probably can agree)
• Tests and Quizzes from IMS
• Specialized descriptors from ADL
– Such as objectives, prerequisites, completion
requirements
Al
Education Specific Portal Services
• Administrative Structure
– degrees, departments, lecturers, Deans ...
• Performance (grading) information
• Homework submission
• Quizzes of various types (multiple choice, random parameters)
• Assessment data access and analysis
• Hierarchical Curriculum structure from document fragment to page to lecture to course
• Napster/Gnutella type P2P distributed information system with personalized dynamic collections (analogy between CDROM of pirated music and dynamic lectures/personal info resource as in RealJukebox)
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Some Science Portals and Services: Gannon
Resource Auctions Allocations
Globus, Legion Condor
X X X X X X X
Nimrod
Events, app schema standards, RMI GSI, MDS, Gram,
GSIFTP, CoG
X X X X X X
Indiana
Grid Accounting,
portal-to-portal protocols, cert/key repository
GSI, GIS, Gram, SRB
X X X X X
Hot Page
Abstract Job Metadata GSI, GIS,
Scheduling
X X X X X X X
Unicore
Event,
Data access services Kerb/GSI, Gram,
GIS, CORBA.
X X X X X X X X
Mississippi
Events, Collab, app resource management Kerb/GSI, MDS
Gram, CORBA, EJB
X X X X X X X
Gateway
Needed Services
Grid Standards used or will use Supported Grid Services
JS JM IS FM AA CT SC EJ
Project JS Job Submission
JM Job Management e.g. File Staging IS Information Service FM File Management AA Authorization
and Accountin CT Compositio
SC Scripting
Some Science Portals and Services: Gannon
JS Job Submission JM Job Management
e.g. File Staging IS Information Service FM File Management AA Authorization
and Accountin CT Compositio
SC Scripting
EJ Job Journaling
CORBA
X X X X X
Discover
OpenSSL, x.509
X X X X X X X
Lattice
Events GSI, GIS via
GPDK
X X X X X X
IPG
LaunchPad
Events GSI, GIS,
Meta-scheduling
X X X X X
ECCE+ELN
Events CoG, Jini, Ninf
Netsolve
X X X X X X
JiPANG/Ninf
Software Installation Globus, CORBA
X X X X X
CoG-ANL
Globus via CoG
X X X X X
GPDK-LBL
Needed Services
Grid Standards used or will use Supported Grid Services
JS JM IS FM AA CT SC EJ Project
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