Open Collaborative Grid Services Architecture OCGSA - PowerPoint PPT Presentation

Title: Open Collaborative Grid Services Architecture OCGSA


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Open Collaborative Grid Services Architecture
(OCGSA)

• Kaizar Amin
• Sandeep Nijsure
• Gregor von Laszewski
• Mathematics and Computer Science Division (MCS)
• Argonne National Laboratory
• 9700 South Cass Ave
• Argonne, IL 60439

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Acknowledgement

• This work was performed under the auspices of the
  U.S. Department of Energy, Office of Advanced
  Scientific Computing, SciDAC program, under
  contract no. FWP 56825.
• Division of Chemical Sciences, Geosciences and
  Biosciences, Office of Basic Energy Sciences,
  Argonne National Laboratory
• Mathematics and Computational Science Division
  at Argonne National Laboratory
• SciDAC Commodity Grid Kit
• SciDAC Collaboratory for Multi-scale Chemical
  Sciences

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Outline

• Introduction
• Motivation
• Collaborative Grid Services Framework
• Commodity technologies in use
• Prototype Application
• Active Thermochemical Tables

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Computational Grids

• Computational Grids enable resource sharing,
  coordinated and interactive problem solving
  across multi-institutional domains in a secure
  context.
• For example
• A biologist can exploit thousands of computers to
  analyze DNA and Gene Mapping
• A group of Thermochemists collaborate to discuss
  thermochemistry data of some new species.

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Web Services

• Standards-based framework defined by the W3C and
  contributed by IBM, Microsoft, and others.
• A platform-independent software component that is
  described by using a service description
  language, provides functionalities to publish its
  interfaces to some registry of services, and can
  be invoked by using appropriate binding
  protocols.

Service Provider
Bind
Publish
Discover
Service Requestor
Service Registry
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Web Services

• Described using the Web Services Description
  Language (WSDL).
• Published and Discovered using the Web Service
  Invocation Language (WSIL) or the Universal
  Description, Discovery, and Integration (UDDI).
• Uses XML-based Simple Object Access Protocol
  (SOAP) as its binding protocol.

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Grid Services

• Marriage of Grid Technology and Web Services.
• The services-oriented concept lends itself to an
  architecture that requires interoperability
  across heterogeneous platforms and exposes all or
  part of its applications on different machines,
  platforms, and domains suitable for Grid
  technologies
• However, Web services support creation, discovery
  and invocation of persistent services. Grid
  architecture requires creation and maintenance of
  transient services.
• Grid services extends the functionality of Web
  services to support the requirements of the Grid.
• Grid services are defined by the Global Grid
  Forum (GGF) as a part of the Open Grid Services
  Architecture (OGSA).

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Open Grid Services Architecture (OGSA)

• Provides an extensible framework of core services
  that support Grid functionalities.
• Building block - Grid Service
• A potentially transient Web Service that conforms
  to a set of predefined conventions defined by the
  Global Grid Forum (GGF)
• Enhances the capabilities of a conventional Web
  Service framework by providing
• Instance/Lifetime Management
• Notification subscription (peer-to-peer
  communication)
• Advanced Registration and Discovery
• GSI Security

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Motivation

• Adhoc Collaborative Grids

Data Store
Application Owner
Collaborator
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Motivation

• Scientific Collaborative Communities

Application
Security Manager
Collaborative Framework
Community Members
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Open Collaborative Grid Services Architecture
(OCGSA)

• OGSA provides a set of core services that can be
  extended to implement high-level services for a
  wide variety of applications (including
  collaborative applications).
• Nevertheless, rather than developing certain key
  high-level Grid services for every collaborative
  application, we propose a framework of services
  that can be inherited by any stand-alone
  application or Grid service with minimum effort
  to transform itself into a collaborative Grid
  service.
• This framework is called the Open Collaborative
  Grid Services Architecture (OCGSA).
• Facilitates Adhoc collaborative Grids

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Open Collaborative Grid Services Architecture
(OCGSA)

• OCGSA framework provides tools which wrap
  scientific applications with an interactive
  service architecture.
• Provides patterns of communications between OCGSA
  components.
• Users with appropriate environment will be able
  to set multi-level security (authorization)
  policies on their applications, thereby providing
  a fine grained control on the community users.
• Any user will be able to expose his
  application(s) in a collaborative environment
  allowing multiple communities to control and
  steer that application(s) in their respective
  sessions.

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Open Collaborative Grid Services Architecture
(OCGSA)
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Collaborative Grid Service

• OCGSA introduces the notion of collaborative Grid
  service
• a Grid service with a set of predefined metadata
  elements and behaviors.
• A collaborative Grid service defines metadata
  regarding the creator, name, description, and
  current members of the group.
• It also provides the interface to handle security
  policies at different levels of the application
  (application level and group level), basic group
  communication facilities, an adequate presence
  management for users, capabilities for
  interactively controlling and steering the
  applications.

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Collaborative Grid Service

• Implements the GridService portType and the
  NotificationSource portType.
• This allows the collaborative service to generate
  publish/subscribe style notification messages to
  its clients by means of which they can
  interactively communicate.
• The NotificationSource portType is provided by
  OGSA however, the OCGSA framework provides
  constructs in the Collaborative Grid Service
  Descriptive Language (cgsdl) by which a developer
  is able to predefine a set of notification topics
  that will be supported by collaborative Grid
  services.
• The collaborative Grid service description
  language is an extension to the Grid service
  description language (gsdl) defined by OGSA and
  is used to describe details of a collaborative
  Grid service.
• The code generator will generate the necessary
  stubs for this definition, and the
  application-specific details for each
  notification topic can be implemented by the
  developer.

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Grid Security Service

• OCGSA uses security mechanisms such as
  authentication, delegation of rights,
  confidentiality, and message integrity as
  specified in the OGSA security draft.
• However, the security service of OCGSA provides
  an advanced multi-level policy based
  authorization.
• On the first level, the application level, the
  application service provider dictates the
  authorization policy regarding the users that can
  access the application.
• The second level is the group level access
  control where group creator specifies the
  authorization policy describing the class of
  users that can participate in the group.
• OCGSA provides mechanisms that allow users to
  define and enforce such authorization policies
  dynamically at runtime without any prior
  configuration support.

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Grid Security Service
Application
Authorization Policies
Proxy Certificate
Security Service
Group Member
Group Creator
User Certificate
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Grid Registration Service

• OCGSA framework requires that every collaborative
  service be associated with a registration service
  so that group instances can be discovered by peer
  users.
• The registration service used in OCGSA is a
  registration Grid service provided by OGSA,
  capable of supporting XPath/XQuery queries.
• Support for such a sophisticated querying
  mechanism is essential because OCGSA enables
  arbitrary users with appropriate credentials to
  query the registration service based on complex
  criteria and identify the service instance
  (group) that they would like to join.

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Grid Database Service

• Databases/Data-stores are key to high performance
  computing applications.
• The Grid database service provides a Grid service
  interface to a Native XML Database (NXD) defined
  by the XMLDB initiative.
• This enables the enforcement of dynamic security
  policies on XML databases used in collaborative
  applications.
• Using the database service, users can store
  arbitrary data in XML format and later retrieve
  it using XPath queries.
• A simple service that can be extended for complex
  functionalities

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Grid Event Logging Service

• The event logging service extends the Grid
  database service to provide an interface to log
  the messages or events communicated between
  online users of a group into a persistent
  database.
• Users that join a particular group at a later
  time can retrieve these events, thereby updating
  themselves about the group's prior activities.
• The event archiving mechanism also enables the
  group members to insert checkpoints into the
  event database and replay the entire or sections
  of the archived collaborative activity when the
  group is off-line.
• It also allows statistical analysis of the group
  activities by other high level services such as
  Grid monitoring service

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Prototype Application
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Active Thermochemical Tables(ATcT)

• Thermochemistry finds applications in disciplines
  such as earth science and engineering.
• Until now, the data necessary for thermochemical
  calculations has been available only in static
  table form, and the algorithms to derive accurate
  model descriptions have been too imprecise to
  deal with the complex chemical reactions.

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Active Thermochemical Tables(ATcT)

• ATcT provides an efficient algorithm whereby the
  static tables are scanned into an Active
  database of thermochemistry data.
• To obtain the thermochemistry data of any new
  species the chemist inputs a complex chemical
  reaction table.
• ATcT generates a chemical network/graph from the
  input file.
• Solving this chemical network results in the
  optimization of the thermo chemistry data for a
  particular species.

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Active Thermochemical Tables(ATcT)

• Requirements
• Chemists can interactively formulate complex sets
  of chemical reactions based on their data-sets
  and then collaboratively steer the application to
  view new thermochemistry data.
• Users have their individual thermochemistry data
  online on WebDAV servers. Based on the
  collaborative interaction, they can exchange
  their individual thermochemistry data or consume
  the newly disseminated information.
• The application must allow the formation of
  dynamic collaborative groups in a secure
  environment without compromising intellectual
  properties.
• Chemists that collaborate in the formulation of
  new thermochemistry data should be able to
  simulate their previous discussions in order to
  investigate certain important issues at a later
  time.

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Active Thermochemical Tables(ATcT)
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Active Thermochemical Tables(ATcT)
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Active Thermochemical Tables(ATcT)
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Future Plans

• Add the following services
• Grid Monitoring Service To determine how and
  when it is necessary to change the dynamically
  instantiated Grid applications (including
  preventive measurements such as service
  replication, service migration, service check
  pointing, and service monitoring).
• Grid Migration Service To be able to migrate
  services and jobs executed with a Grid Execution
  Factory Service to a location that is better
  suited, based on performance and quality of
  service descriptions and policies.
• Grid Services Flow Language Engine Develop a
  Grid service flow processing engine that allows
  to orchestrate the different services.

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References

• Kaizar Amin, Sandeep Nijsure, Gregor von
  Laszewski. A Grid Services Framework for
  Collaborative Applications. Poster in IEEE/ACM
  SC2002 Conference, November 2002, Baltimore, USA.
• Gregor von Laszewski, Branko Ruscic, Patrick
  Wagstrom, Sriram Krishnan, Kaizar Amin, Sandeep
  Nijsure, Reinhardt Pinzon, Melita L. Morton,
  Sandra Bittner, Mike Minkoff, Al Wagner, and John
  C. Hewson. A Grid Service Based Active
  Thermochemical Table Framework. In Third
  International Workshop on Grid Computing, Lecture
  Notes in Computer Science, Baltimore, MD, 18 Nov.
  2002.
• B. Ruscic, M. Litorja, and R. L. Asher.
  Ionization Energy of Methylene Revisited
  Improved Values for the Enthalpy of Formation of
  CH2 and the Bond Energy of CH3 via Simultaneous
  Solution of the Local Thermochemical Network. J.
  Phys. Chem. A., 10386258633, 1999.
• Gregor von Laszewski, Ian Foster, Jarek Gawor,
  and Peter Lane. A Java Commodity Grid Kit.
  Concurrency and Computation Practice and
  Experience, 13(8-9)643-662, 2001.
  http//www.globus.org/cog/

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Thank you

• QUESTIONS !!