Transcript Education and Grid Services Geoffrey Fox Professor of Computer Science, Informatics, Physics Pervasive Technology Laboratories Indiana University Bloomington IN 47404 [email protected] http://www.infomall.org http://www.grid2002.org.

Education and Grid Services
Geoffrey Fox
Professor of Computer Science, Informatics, Physics
Pervasive Technology Laboratories
Indiana University Bloomington IN 47404
[email protected]
http://www.infomall.org
http://www.grid2002.org
Who is Geoffrey Fox?
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Undergraduate degree in math, PhD Theoretical Physics at Cambridge
University
Theory, Experiment, Computation, Phenomenology of particle physics
Caltech for 20 years
• Worked with Feynman, Hey, Wolfram
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Dean for educational computing and associate provost for computing Caltech;
Professor of Physics; department chair
Developed parallel computers for science
Computer Science Syracuse, Florida State, Indiana
• Main area of research last 20 years
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Interdisciplinary work in computational science with many fields – Earth
Science/Biology at moment
Chief technologist Anabas corporation (WebEx done right)
• Technology for distance education on the Grid
• Teaching class from Indiana to Jackson State this semester
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Informatics, Computer Science, Physics at Indiana
• Pervasive Technology Lab Information technology initiative at Indiana University
funded by Lilly
• Director Community Grids Laboratory
What is a MLE Managed Learning Environment
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An MLE is the full range of information systems and
processes of an institution that contributes directly or
indirectly to learning and the management of learning
A Virtual Learning Environment VLE is the subset of
MLE components that provide online learning
interactions for learners and teachers
MLE Components include enrollment, security, portal,
digital library functions on learning resources, access to
administrative material, payment, attendance tracking,
authoring curriculum, learning planners, quizzes,
homework, grading, assessment, distance teaching,
computer-aided instruction, collaboration tools
Some Players with Education Grid like Capabilities
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IMS and ADL in the USA have set standards for some of the
special learning metadata structures
CHEF (Michigan) and Colloquia (Bangor) are academic
groupware projects aimed at education
• Access Grid from Argonne is Audio-Video conferencing
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Sakai and OKI are Mellon Foundation projects implementing
electronic learning capabilities
Blackboard and WebCT are popular (some places) academic elearning support systems
• Several inhouse efforts like OnCourse at Indiana
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Docent, Topclass etc. are learning content management systems
LCMS mainly selling to corporate training market
Centra, Interwise, Placeware, WebEx, GrooveNetworks are well
known collaboration systems that might support distance
learning/tutoring and participatory education
Grids in a Nutshell
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Grids are by definition the best of HPCC, Web Services, Agents,
Distributed Objects, Peer-to-peer networks, Collaborative
environments
Grid applications are typically zero or one very large
supercomputers, lots of conventional machines, with unlimited
data and/or people supporting an electronic (virtual) community
• Data sources and people are latency tolerant …
• Multiple supercomputers (or clusters) on same Grid as in
TeraGrid/ETF largely for sharing of data and by people
Grids are supported by Global Grid Forum, W3C, OASIS …
setting standards
Grids are a “service oriented architecture” hiding irrelevant
details
• Services are electronic resources communicating by messages
• Message based architecture gives scalable loosely coupled
component model
Information/Knowledge Grids
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Distributed (10’s to 1000’s) of data sources (instruments,
file systems, curated databases …)
Data Deluge: 1 (now) to 100’s petabytes/year (2012)
• Moore’s law for Sensors
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Possible filters assigned dynamically (on-demand)
• Run image processing algorithm on telescope image
• Run Gene sequencing algorithm on compiled data
Needs decision support front end with “what-if”
simulations
Metadata (provenance)
critical to annotate data
Integrate across experiments
as in multi-wavelength
astronomy
Data Deluge comes from pixels/year available
A typical Web Service
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In principle, services can be in any language (Fortran .. Java ..
Perl .. Python) and the interfaces can be method calls, Java RMI
Messages, CGI Web invocations, totally compiled away (inlining)
The simplest implementations involve XML messages (SOAP) and
programs written in net friendly languages like Java and Python
Web Services
WSDL interfaces
Portal
Service
Security
WSDL interfaces
Web Services
Payment
Credit Card
Catalog
Warehouse
Shipping
control
Each service should be
able to run independently
on separate machines
Typical Grid Architecture
Re-use
Application
Customization
User
Services
Application
Service
Portal
Services
Application
Service
Libraries
Application
Service
Middleware
Re-use
“Core”
Grid
System
Services
System
Services
System
Services
Raw (HPC)
Resources
Database
Some Technical Issues
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All IT approaches support systems with multiple
capabilities
• They often reveal and/or standardize interfaces
• They could be different method calls, Java classes, or
Web/Grid service interfaces
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We will ONLY use the word Service when interface can
be efficiently accessed by messages with service as an
isolated single service
• Grids build systems from message-based services
Capabilities
often called services
Module
Module
Service even if NOT using
Servicea
Messages
B
A
B
A
Service
Oriented Architecture
Method Calls
1 to 10 microseconds
10 to 1000 millisecond latency
Message-based or Method-based
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Method-based interfaces are most efficient but can only
be run in that fashion in a single monolithic
implementation
• One service with multiple ports
• i.e. each interface might be accessed via message but
all capabilities need to be co-located
• Technologies like Java RMI allow distributed objects
but requires serialization (often non trivial) and
unclear if application supports performance loss
“Message-based services” support standards and
distributed deployment with easy use of standards
compliant services from different implementers.
Sakai
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The University of Michigan, Indiana University, MIT, Stanford,
and the uPortal consortium are joining forces to integrate and
synchronize their considerable educational software into a preintegrated collection of open source tools.
Sakai builds on OKI – Open Knowledge Initiative – interfaces
These Open Service Interface Definitions were developed
outside the Grid process but appear to have overlaps with
many Web service and Grid standards
• Note OGSA-DAI, Security, Workflow, WS-Notification,
Grid monitoring, WebDAV overlaps
Although they are called “services”, I think they are being
developed initially inside a (single) Java container
Does not address real-time collaboration except for chat
Portals
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These are used rather inconsistently for
• A general term for the whole user experience with an interface to multiple
capabilities
• Narrow specification of certain capabilities such as customization, server
side support for web page generation, aggregation of document fragments
(one per service), security
• Broad specification to include both user interface and services
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Note portals tend to be monolithic frameworks because that’s
how one used to build such things
• Jetspeed and CHEF’s modification of it are both frameworks
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Portals need to be broken up into distributed message based
services for security, customization, layout, rendering
• Shouldn’t invest too much in today’s frameworks although they have
some wonderful features
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However Portals do encourage “component” model for user
interfaces and so this fits service model so every service can be
packaged with its (document fragment) user interface
• So portlets are good even if containers primitive
The OGCE Computing Grid Portal
• Provides Portlets for
– Management of user proxy
certificates
– Remote file Management via
Grid FTP
– News/Message systems
• for collaborations
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–
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Grid Event/Logging service
Access to OGSA services
Access to directory services
Specialized Application Factory
access
• Distributed applications
• Workflow
– Access to Metadata Index tools
• User searchable index
– Real Time Collaboration
• Audio/Video Conferencing
OGCE
Consortium
Example Capability: File Management
• Grid FTP portlet– Allow
User to manage remote file
spaces
– Uses stored proxy for
authentication
– Upload and download files
– Third party file transfer
User
Jetspeed Portal Server
1 of many Portlets
• Request that GridFTP server A send aGridFTP
file to GridFTP server B
Server A
• Does not involve traffic through portal
server
GridFTP
Service
GridFTP
Server B
OGCE
Consortium
Education Grids
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Education Grids can be considered from at least two
points of view
1) Exploiting e-Science and other relevant research
government or business grids whose resources can be
adapted for use in education
• Opportunity to make education more “real” and to give
students an idea what scientific research is like
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2) Support the virtual organization that is the teacher
and learner community
• Actually this community is heterogeneous with teachers,
learners, parents, employers, publishers, informal education,
university staff ….
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Build the Education Grid as a Grid of Grids
Typical Science Grid
Service such as Research
Database or simulation
Campus or
Enterprise
Administrative
Grid
Learning Management
or LMS Grid
Digital
Library
Grid
Science Grids
Bioinformatics
Earth Science …….
Transformed by Grid Filter
to form suitable for education
Publisher
Grid
Education Grid
Inservice Teachers
Preservice Teachers
School of Education
Teacher Educator
Grids
Student/Parent …
Community Grid
Informal
Education
(Museum)
Grid
Planning Grid
Education as a Grid of Grids
Education Grid of Grids
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Services in an Education Grid fall into three classes
1) Those that special to Education such as quiz (as in
IMS), learning plan or grading services
2) Those that are important but can be taken from
other Grids such as collaboration and security
3) Those that come from other Grids and are refactored
for education
• The simulation is reduced in size
• The bioinformatics database interface is simplified
e-Science
Resource
Filter
Education Grid View
of e-Science Resource
Education Grid
Repositories
Federated Databases
Database
Sensors
Streaming
Data
Field Trip Data
Database
Research
SERVOGrid
Data
Filter
Services
Research
Simulations
Geoscience Research and
Education Grids
Customization
Services
From
Research
to Education
?
Discovery
Services
Education
Analysis and
Visualization
Portal
Education
Grid
Computer
Farm
XGSP Web Service MCU Architecture
Use Multiple Media servers to scale to many codecs and many
versions of audio/video mixing
Session Server
XGSP-based Control
NaradaBrokering
All Messaging
NB Scales as
distributed
Admire
Web
Services
SIP
H323
Media Servers
Filters
High Performance (RTP)
and XML/SOAP and ..
Access Grid
Gateways convert to uniform XGSP Messaging
NaradaBrokering
Native XGSP
Requirements or Issues to be Addressed I
• Interoperability: Several standards – e.g.
H323, T120, SIP, Access Grid – which are
inconsistent with themselves and with modern
Web standards
• Integration: Integrate all forms of collaboration
– instant messenger, audio-video conferencing,
application sharing
• Life-cycle costs: use commodity software
components
• Extensibility: Interfaces defined for adding
new capabilities
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Requirements or Issues to be Addressed II
Performance: Allow maximum performance
with given network with no unnecessary client
or server overheads
Fault Tolerance: Fault tolerant session control
Security: Support multiple levels of security for
clients, servers and communication traffic
Scalability: Current systems are often limited
by architecture or implementation (such as a
single server) in number of simultaneous
participants
Pervasive Access: Need to support wide
range of clients from hand-held devices to
sophisticated desktop system.
Ease of Use: Simple web portal interface; no
Collaboration Architecture
• Use Grid and Web Service base architecture
• Define XML-based Collaboration Interface specification
capturing semantics of existing standards
• Define open interfaces allowing both third party services to be
developed and to allow competitive implementation of base
infrastructure
• Use software overlay network to support needed dynamic
routing and message-based architecture
• Use active measurements to find network performance and
network
or server/broker
• Web Service
architecturefaults
with N logN servers to support
• Use
Web Service message based security
N participants
• 1000
simultaneous streams
needsfor
around
50 low-end
• Use
publish/subscribe
paradigm
all messaging
to support
multi-participant
Linux servers sessions and archiving
• Does
not need multi-cast;
supports web-cams
• Use
distributed
scalable fault-tolerant
middleware including
WS-RM
(Web
Service
Messaging)
• Supports
Polycom
andReliable
Access Grid
clients or equivalent
Summary
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Grids are inevitably important for Education
Grid of Grids interesting way to build “new Grids” that might be
accepted by skeptical participants and enhance re-use
IMS has set data but not many service standards
• Partial step to interoperability
Sakai is building modern (probably wonderful) open e-learning
capabilities but appears not to be a Grid/WS standards compliant
service architecture
Current academic/commercial systems are successful but
monolithic and perhaps are too education-specific
Opportunity to build service-based Education Grid Infrastructure
interacting with broad community (from Grids to WS to Schools
of Education) exploiting other Grids
Can build collaboration – A/V Conferencing, Shared applications,
groupware – in Grid/WS architecture
Can develop best practice and tools to allow e-Science grids to be
linked to education
Can encourage use of component-based portals