The Anatomy of the Grid: An Integrated View of Grid Architecture

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The Anatomy of the Grid An Integrated View of
Grid Architecture

• Carl Kesselman
• USC/Information Sciences Institute
• Ian Foster, Steve Tuecke
• Argonne National Laboratory

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Outline and Goals

• Define what is (and isnt) a grid in terms of a
  layered protocol architecture
• Understand the role of protocols, services, APIs
  and tools in the deployment and use of Grids
• Understand what role Globus plays
• Understand the role of other technologies

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What is a Grid?

• Grid language has been driven by genesis from
  metacomputing, but
• In practice, the Grid is about resource sharing
  and coordinated problem solving in dynamic,
  multi-institutional virtual organizations
• Focus on how to enable, maintain and control the
  sharing of resources to achieve a common goal

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Some Useful Definitions

• Network Protocol
• A formal description of message formats and a set
  of rules for exchange of messages
• Rules define sequences of message exchange, and
  potentially resulting behavior
• Protocol may define state-change in endpoint
• Network Enabled Services
• Defines a set of capabilities
• Protocol defines interaction with service
• All services require protocols, although not all
  protocols are to services

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More definitions

• Resource
• Entity that is to be shared
• Provides some capabilities, that can be accessed
  via interface (API) or protocol
• Application Programmer Interface (API)
• Software Development Kit (SDK)
• Package that enables application development,
  consisting of one or more APIs, and programming
  tools

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Protocols Make the Grid

• Protocols and APIs
• Protocols enable interoperability
• APIs enable portability
• Sharing is about interoperability, so
• Grid architecture should be about protocols

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Grid Services Architecture Previous Perspective
a rich variety of applications ...
Applns
Appln Toolkits
Remote data toolkit
Remote sensors toolkit
Async. collab. toolkit
Remote viz toolkit
Remote comp. toolkit
...
Protocols, authentication, policy, resource
management, instrumentation, discovery, etc.,
etc.
Grid Services
Grid Fabric
Grid-enabled archives, networks, computers,
display devices, etc. associated local services

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Characteristics of Grid Services Architecture

• Identifies separation of concerns
• Isolates Grids from languages and specific
  programming environments
• Makes provisions for generic and application
  specific functionality
• Protocols not explicit in architecture
• fails to make clear distinction between language,
  service and networking issues

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Layered Grid Protocol Architecture
Application
User
Grid
Resource
Connectivity
Fabric
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Important Points

• Being Grid-enabled requires speaking appropriate
  protocols
• Protocol only requirement, not reachability
• Protocols can be used to bridge local resources
  or local Grids
• Intergrid as analog to Internet
• Built on Internet protocols
• Independent of language and implementation
• Focus on interaction over network
• Services exist at each level

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Protocols, services and interfaces
Applications
Languages/Frameworks
Connectivity APIs
Connectivity Protocols
Local Access APIs and protocols
Fabric Layer
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How does Globus fit in?

• Defines connectivity and resource protocols
• Enables definition of grid and user protocols
• Globus provides some of these, others defined by
  other groups
• Defines range of APIs and SDKs that leverage
  Resource, Grid and User protocols

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Fabric

• Local access to logical resource
• May be real component, e.g. CPU, software module,
  filesystem
• May be logical component, e.g. Condor pool
• Protocol or API mediated
• Fabric elements include
• SSP, ASP, peer-to-peer, Entropia-like, and
  enterprise level solutions

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Connectivity Protocols

• Two classes of connectivity protocols underlie
  all other components
• Internet communication
• Application, transport and internet layer
  protocols
• I.e., transport, routing, DNS, etc.
• Security
• Authentication and delegation
• Discussed below

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Security

• Protocols
• TLS with delegation
• Services
• K5ssl, Globus Authorization Service
• APIs
• GSS-API, GAA, SASL, gss_assist
• SDKs
• GlobusIO

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Resource Protocols

• Resource management,
• Storage system access
• Network quality of service
• Data movement
• Resource information

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Resource Management

• Protocols
• GRAMGARA (on HTTP)
• Resource services
• Gatekeeper, JobManager, SlotManager
• APIs and SDKs
• GRAM API, JavaCog Client, DUROC

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Data Transport

• Protocols
• Grid FTP, LDAP for replica catalog
• Services
• FTP, LDAP replica catalog
• APIs and SDKs
• GridFTP client library, copy URL API, replica
  catalog access, replica selection

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Resource Information

• Protocol
• LDAP V3, Registration/Discovery protocol
• Service
• GRIS
• APIs SDKs
• C API JNDI, PerlLDAP, .

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Grid Protocols

• Grid Information Index Services
• LDAP and Service registration protocol,
• GIIS service
• LDAP APIs and specialized information API
• Co-allocation and brokering
• GRAM (HTTPRSL)
• DUROC service
• DUROC client API, end-to-end reservation API

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Grid Protocols (cont)

• Online authentication, authorization services
• HTTP
• MyProxy, Group policy servers
• Myproxy API, GAA API,
• Many others (e.g.)
• Resource discovery (Matchmaker)
• Fault recovery

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User Protocols

• In general, there are many of these, they tend to
  be on off, and not well defined
• Examples
• Portal toolkits (e.g. Hotpage)
• Netsolve
• Cactus framework

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Summary

• Grids are about sharing, not making big MPI jobs
• Well defined protocol architecture is essential
  to understanding and progress
• Provides a framework for figuring out where the
  pieces fit
• Globus provides many basic protocols and services
• Interoperability between different Grid components