The Anatomy of the Grid Enabling Scalable Virtual Organizations

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The Anatomy of the GridEnabling Scalable
Virtual Organizations

• Ian Foster
• Mathematics and Computer Science Division
• Argonne National Laboratory
• and
• Department of Computer Science
• The University of Chicago
• http//www.mcs.anl.gov/foster

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Grids are hot
Computational Data Information Access Knowledge

• DISCOM
• SinRG

APGrid
TeraGrid
but what are they really about?
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Issues I Propose to Address

• Problem statement
• Architecture
• Globus Toolkit
• Futures

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The Grid Problem

• Resource sharing coordinated problem solving
  in dynamic, multi-institutional virtual
  organizations

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Elements of the Problem

• Resource sharing
• Computers, storage, sensors, networks,
• Sharing always conditional issues of trust,
  policy, negotiation, payment,
• Coordinated problem solving
• Beyond client-server distributed data analysis,
  computation, collaboration,
• Dynamic, multi-institutional virtual orgs
• Community overlays on classic org structures
• Large or small, static or dynamic

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Grid Communities ApplicationsData Grids for
High Energy Physics
Image courtesy Harvey Newman, Caltech
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Grid Communities and ApplicationsNetwork for
Earthquake Eng. Simulation

• NEESgrid national infrastructure to couple
  earthquake engineers with experimental
  facilities, databases, computers, each other
• On-demand access to experiments, data streams,
  computing, archives, collaboration

NEESgrid Argonne, Michigan, NCSA, UIUC, USC
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Grid Communities and ApplicationsMathematicians
Solve NUG30

• Communityan informal collaboration of
  mathematicians and computer scientists
• Condor-G delivers 3.46E8 CPU seconds in 7 days
  (peak 1009 processors) in U.S. and Italy (8
  sites)
• Solves NUG30 quadratic assignment problem

14,5,28,24,1,3,16,15, 10,9,21,2,4,29,25,22, 13,26,
17,30,6,20,19, 8,18,7,27,12,11,23
MetaNEOS Argonne, Iowa, Northwestern, Wisconsin
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Grid Communities and ApplicationsHome Computers
Evaluate AIDS Drugs

• Community
• 1000s of home computer users
• Philanthropic computing vendor (Entropia)
• Research group (Scripps)
• Common goal advance AIDS research

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Grid Architecture
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Why Discuss Architecture?

• Descriptive
• Provide a common vocabulary for use when
  describing Grid systems
• Guidance
• Identify key areas in which services are required
  
• Prescriptive
• Define standard Intergrid protocols and APIs to
  facilitate creation of interoperable Grid systems
  and portable applications

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What Sorts of Standards?

• Need for interoperability when different groups
  want to share resources
• E.g., IP lets me talk to your computer, but how
  do we establish maintain sharing?
• How do I discover, authenticate, authorize,
  describe what I want to do, etc., etc.?
• Need for shared infrastructure services to avoid
  repeated development, installation, e.g.
• One port/service for remote access to computing,
  not one per tool/application
• X.509 enables sharing of Certificate Authorities

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So, in Defining Grid Architecture, We Must
Address

• Development of Grid protocols services
• Protocol-mediated access to remote resources
• New services e.g., resource brokering
• On the Grid speak Intergrid protocols
• Mostly (extensions to) existing protocols
• Development of Grid APIs SDKs
• Facilitate application development by supplying
  higher-level abstractions
• The (hugely successful) model is the Internet
• The Grid is not a distributed OS!

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The Role of Grid Services(aka Middleware) and
Tools
net
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Layered Grid Architecture(By Analogy to Internet
Architecture)
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Protocols, Services, and InterfacesOccur at Each
Level
Applications
Languages/Frameworks
Collective Service APIs and SDKs
Collective Service Protocols
Collective Services
Resource APIs and SDKs
Resource Service Protocols
Resource Services
Connectivity APIs
Connectivity Protocols
Local Access APIs and Protocols
Fabric Layer
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Where Are We With Architecture?

• No official standards exist
• Nor is it clear what this would mean
• But
• Globus Toolkit has emerged as the de facto
  standard for several important Connectivity,
  Resource, and Collective protocols
• GGF has an architecture working group
• Technical specifications are being developed for
  architecture elements e.g., security, data,
  resource management, information

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The Globus Toolkit
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Grid Services Architecture (1)Fabric Layer

• Just what you would expect the diverse mix of
  resources that may be shared
• Individual computers, Condor pools, file systems,
  archives, metadata catalogs, networks, sensors,
  etc., etc.
• Few constraints on low-level technology
  connectivity and resource level protocols form
  the neck in the hourglass
• Globus toolkit provides a few selected components
  (e.g., bandwidth broker)

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Grid Services Architecture (2)Connectivity
Layer Protocols Services

• Communication
• Internet protocols IP, DNS, routing, etc.
• Security Grid Security Infrastructure (GSI)
• Uniform authentication authorization mechanisms
  in multi-institutional setting
• Single sign-on, delegation, identity mapping
• Public key technology, SSL, X.509, GSS-API
• Supporting infrastructure Certificate
  Authorities, key management, etc.

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CREDENTIAL
Single sign-on via grid-id
Assignment of credentials to user proxies
Globus Credential
Mutual user-resource authentication
Site 2
Authorization
Authenticated interprocess communication
Mappingtolocal ids
Certificate
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GSI Futures

• Scalability in numbers of users resources
• Credential management
• Online credential repositories (MyProxy)
• Account management
• Authorization
• Policy languages
• Community authorization
• Protection against compromised resources
• Restricted delegation, smartcards

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GSI FuturesCommunity Authorization
1. CAS request, with

user/group
CAS

resource names

membership

Does the
and operations

collective policy
resource/collective
authorize this
2. CAS reply, with

membership

request for this

capability

and resource CA info

user?

collective policy
information

User

Resource

3. Resource request,

authenticated with

Is this request
capability

authorized by
the
local policy
capability?

information

4. Resource reply

Is this request
authorized for
the CAS?

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Grid Services Architecture (3)Resource Layer
Protocols Services

• Resource management GRAM
• Remote allocation, reservation, monitoring,
  control of compute resources
• Data access GridFTP
• High-performance data access transport
• Information MDS (GRRP, GRIP)
• Access to structure state information
• others emerging catalog access, code
  repository access, accounting,
• All integrated with GSI

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GRAM Resource Management Protocol

• Grid Resource Allocation Management
• Allocation, monitoring, control of computations
• Simple HTTP-based RPC
• Job request
• Returns a job contact Opaque string that can
  be passed between clients, for access to job
• Job cancel, Job status, Job signal
• Event notification (callbacks) for state changes
• Pending, active, done, failed, suspended
• Servers for most schedulers C and Java APIs

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Resource Management Futures

• GRAM-2 protocol (ETA late 2001)
• Advance reservations multiple resource types
• Recoverable requests, timeout, etc.
• Use of SOAP (RPC using HTTP XML)
• Policy evaluation points for restricted proxies

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Data Access Transfer

• GridFTP extended version of popular FTP protocol
  for Grid data access and transfer
• Secure, efficient, reliable, flexible,
  extensible, parallel, concurrent, e.g.
• Third-party data transfers, partial file
  transfers
• Parallelism, striping (e.g., on PVFS)
• Reliable, recoverable data transfers
• Reference implementations
• Existing clients and servers wuftpd, nicftp
• Flexible, extensible libraries

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Grid Services Architecture (4)Collective Layer
Protocols Services

• Index servers aka metadirectory services
• Custom views on dynamic resource collections
  assembled by a community
• Resource brokers (e.g., Condor Matchmaker)
• Resource discovery and allocation
• Replica management and replica selection
• Optimize aggregate data access performance
• Co-reservation and co-allocation services
• End-to-end performance
• Etc., etc.

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The Grid Information Problem

• Large numbers of distributed sensors with
  different properties
• Need for different views of this information,
  depending on community membership, security
  constraints, intended purpose, sensor type

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The Globus Toolkit Solution MDS-2

• Registration enquiry protocols, information
  models, query languages
• Provides standard interfaces to sensors
• Supports different directory structures
  supporting various discovery/access strategies

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Resource Management Architecture
RSL specialization
RSL
Application
Information Service
Queries
Info
Ground RSL
DUROC MPICH-G2
Simple ground RSL
Local resource managers
GRAM
GRAM
GRAM
LSF
Condor
NQE
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Data Grid Architecture(See talk by Sudharshan
Vazhkudai)
Attribute Specification
Replica Catalog
Metadata Catalog
Application
Multiple Locations
Logical Collection and Logical File Name
MDS
Selected Replica
Replica Selection
GridFTP commands
Performance Information Predictions
NWS
Disk Cache
Tape Library
Disk Array
Disk Cache
Replica Location 1
Replica Location 2
Replica Location 3

• Virtual data transparency wrt location
  and materialization (www.griphyn.org)

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Grid Futures
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Large GridProjectsare in Place

• DOE ASCI DISCOM
• DOE Particle Physics Data Grid
• DOE Earth Systems Grid
• DOE Science Grid
• DOE Fusion Collaboratory
• European Data Grid
• Egrid (see talk by G. Allen et al.)
• NASA Information Power Grid
• NSF National Technology Grid
• NSF Network for Earthquake Eng Simulation
• NSF Grid Application Development Software
• NSF Grid Physics Network

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Problem Evolution

• Past-present O(102) high-end systems Mb/s
  networks centralized (or entirely local) control
• I-WAY (1995) 17 sites, week-long 155 Mb/s
• GUSTO (1998) 80 sites, long-term experiment
• NASA IPG, NSF NTG O(10) sites, production
• Present O(104-106) data systems, computers Gb/s
  networks scaling, decentralized control
• Scalable resource discovery restricted
  delegation community policy GriPhyN Data Grid
  100s of sites, O(104) computers complex policies
• Future O(106-109) data, sensors, computers Tb/s
  networks highly flexible policy, control

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The FutureAll Software is Network-Centric

• We dont build or buy computers anymore, we
  borrow or lease required resources
• When I walk into a room, need to solve a problem,
  need to communicate
• A computer is a dynamically, often
  collaboratively constructed collection of
  processors, data sources, sensors, networks
• Similar observations apply for software

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And Thus

• Reduced barriers to access mean that we do much
  more computing, and more interesting computing,
  than today gt Many more components ( services)
  massive parallelism
• All resources are owned by others gt Sharing (for
  fun or profit) is fundamental trust, policy,
  negotiation, payment
• All computing is performed on unfamiliar systems
  gt Dynamic behaviors, discovery, adaptivity,
  failure

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Summary

• The Grid problem Resource sharing coordinated
  problem solving in dynamic, multi-institutional
  virtual organizations
• Grid architecture Emphasize protocol and service
  definition to enable interoperability and
  resource sharing
• Globus Toolkit as a source of protocol and API
  definitions, reference implementations
• For more info www.globus.org, www.griphyn.org,
  www.gridforum.org