grid computing anda iamnitchi federated distributed systems, fall ‘06 including slides adapted...
TRANSCRIPT
Grid Computing
Anda IamnitchiFederated Distributed Systems, Fall ‘06
Including slides adapted from presentations byIan Foster, Lee Liming, Paul Jeffreys
Front page FT, 7th March 2000
But…
What is the Grid?
“Resource sharing & coordinated problem solving in dynamic, multi-institutional virtual organizations”
“When the network is as fast as the computer's internal links, the machine disintegrates across the net into a set
of special purpose appliances” (George Gilder) “The Anatomy of the Grid”, Foster, Kesselman, Tuecke, 2001
Motivation (1):Revolution in Science
• Pre-Internet– Theorize &/or experiment, alone
or in small teams; publish paper
• Post-Internet– Construct and mine large databases of
observational or simulation data– Develop simulations & analyses– Access specialized devices remotely– Exchange information within
distributed multidisciplinary teams
Motivation (2):Revolution in Business
• Pre-Internet– Central data processing facility
• Post-Internet– Enterprise computing is highly distributed,
heterogeneous, inter-enterprise (B2B)– Business processes increasingly
computing- & data-rich– Outsourcing becomes feasible =>
service providers of various sorts
The (Power) Grid:On-Demand Access to Electricity
Time
Qua
lity,
eco
nom
ies
of s
cale
By Analogy, A Computing Grid
• Decouple production and consumption– Enable on-demand access– Achieve economies of scale– Enhance consumer flexibility– Enable new devices
Not Exactly a New Idea …
• “The time-sharing computer system can unite a group of investigators …. one can conceive of such a facility as an … intellectual public utility.”– Fernando Corbato and Robert Fano, 1966
• “We will perhaps see the spread of ‘computer utilities’, which, like present electric and telephone utilities, will service individual homes and offices across the country.”– Len Kleinrock, 1967
But Things are Different Now …
Computing isn’t Really Like Electricity
• I import electricity but must export data• “Computing” is not interchangeable but highly
heterogeneous: data, sensors, services, …• This complicates things; but also means that the sum
can be greater than the parts – Real opportunity: Construct new capabilities dynamically from
distributed services
• Raises fundamental questions– Achieving economies of scale– Quality of service across distributed services– Applications that exploit synergies
How Can We Tell Hype from Facts?
• Everyday problem, isn’t it?• Learn/verify the facts• Know the context
– Multi-institutional (== federated)• Thus, a cluster? (Sun Grid Engine!!!)
– Dynamic (somewhat)• Look at results
– Research innovation (in computer and computational science)
– Scientific discovery– Existing/deployed grids
“We must addressscale & failure”
P2P and Grids: Resource Sharing Across Administrative Domains
“We need infrastructure”
“On Death, Taxes and the Convergence of P2P and Grids”, Foster, Iamnitchi 2003
Compare & Contrast (1):Definitions
Grid:
P2P:
• “Infrastructure that provides dependable, consistent, pervasive, and inexpensive access to high-end computational capabilities” (1998)
• “A system that coordinates resources not subject to centralized control, using open, general-purpose protocols to deliver nontrivial QoS” (2002)
• “Applications that takes advantage of resources at the edges of the Internet” (2000)
• “Decentralized, self-organizing distributed systems, in which all or most communication is symmetric” (2002)
Compare and Contrast (2):Details of Deployed Systems
• Target communities and incentives
• Resources engaged
• Applications
• Scale and failure
• Services and infrastructure
Target Communities & IncentivesGrid• Established communities
– Science, some industry– Homogeneous– Restricted participation
• Good behavior: – Implicit incentives– Means to enforce it
Consequences:• Trust• Well-defined “tax base”• Less flexibility?
P2P• Anonymous individuals
• No implicit incentives for good behavior
Consequences: • No trust• Free riding• Implicit incentives for cheating: Seti@home,
music sharing
ResourcesGrid• More diverse (in type):
– Files, storage, computing power, network, instruments
• More powerful• Good availability• Well connected• Technical support
Consequence:• Costly resource integration
P2P• Computing cycles XOR files• Less powerful• Intermittent participation
– Gnutella: avg. lifetime 1h (‘01)– MojoNation: 1/6 users always on– Overnet: 50% nodes available 70% of time over a
week (‘02)
• Variably connected• Some technical support as community effort
Consequence:• Ease of integration of new resources an early
priority
ApplicationsGrid• Often complex & involving various combinations
of– Data manipulation– Computation– Tele-instrumentation
• Wide range of computational models, e.g.– Embarrassingly ||– Tightly coupled – Workflow
Consequences:– Complexity often inherent in the application
itself– (Inevitably?) Complex infrastructure to
support applications
P2P• Some
– File sharing– Number crunching– Content distribution– Measurements
• “Toy” applications only?– Albeit very popular “toys”!
Consequence:– Complexity often derives from scale
Scale and FailureGrid• Moderate number of entities
– 100s institutions, 1000s users• Large amounts of activity
– 4.5 TB/day (D0 experiment)• Approaches to failure reflect
assumptions– E.g., centralized components
P2P• Large numbers of entities:
– Millions of users• Moderate activity
– E.g., 1-2 TB in Gnutella (’01)• Diverse approaches to failure
– Some centralized (SETI, …)– Some highly self-configuring
FastTrack 3,488,719
eDonkey 1,661,132
iMesh 1,211,965
Overnet 1,146,880
MP2P 250,927
Gnutella 219,009
DirectConnect 204,237
(www.slyck.com, January 25, 2004)
Grids for Physics: LHC Computing Grid
Services and InfrastructureGrid• Standard protocols (Global Grid Forum,
etc.)• De facto standard software (open source
Globus Toolkit)• Shared infrastructure (authentication,
discovery, resource access, etc.)
Consequences:• Reusable services• Large developer & user communities• Interoperability & code reuse
P2P• Each application defines & deploys
completely independent “infrastructure”
• JXTA, BOINC, XtremWeb?• Efforts started to define common
APIs, albeit with limited scope to date
Consequences:• New (albeit simple) install per
application • Interoperability & code reuse not
achieved
Convergent Environment: Large, Dynamic, Self-Configuring Grids
Scale & volatility
Functionality &infrastructure
Grids
P2P
•Large scale•Weaker trust assumptions•Ease of integration
•No centralized authority•Intermittent resource/user participation•Diversity in:
•Shared resources•Sharing characteristics
•Variable technical support•Infrastructure (sharable services)
•Support for diverse applications
Existing Technologies are Helpful,but Not Complete Solutions
• Peer-to-peer technologies– Limited scope and mechanisms
• Enterprise-level distributed computing– Limited cross-organizational support
• Databases– Vertically integrated solutions
• Web services– Not dynamic
• Semantic web– Limited focus
What’s Missing is Support for …
• Sharing & integration of resources, via– Discovery– Provisioning– Access (computation, data, …)– Security – Policy– Fault tolerance– Management
• In dynamic, scalable, multi-organizational settings
Building the Grid
• Open source software– Globus Toolkit® , UK OGSA DAI, Condor, …
• Open standards– OGSA, other GGF, IETF, W3C standards, …
• Open communities– Global Grid Forum, Globus International, collaborative
projects, …
• Open infrastructure– UK eScience, NSF Cyberinfrastructure, StarLight, AP-
Grid, …
Globus Toolkit® History
0
5000
10000
15000
20000
25000
30000
1997 1998 1999 2000 2001 2002
Do
wn
loa
ds
pe
r M
on
th f
rom
ftp
.glo
bu
s.o
rg
DARPA, NSF, and DOE begin funding Grid work
NASA beginsfunding Grid work,DOE adds support
The Grid: Blueprint for a New Computing
Infrastructure published
GT 1.0.0Released
Early ApplicationSuccesses Reported
NSF & European CommissionInitiate Many New Grid Projects
Anatomy of the GridPaper Released Significant
CommercialInterest inGrids
Physiology of the GridPaper Released
GT 2.0Released
Does not include downloads from:NMI, UK eScience, EU Datagrid,IBM, Platform, etc.
How It Started
While helping to build/integrate a diverse range of distributed applications, the same problems kept showing up over and over again.
– Too hard to keep track of authentication data (ID/password) across institutions
– Too hard to monitor system and application status across institutions
– Too many ways to submit jobs
– Too many ways to store & access files and data
– Too many ways to keep track of data
– Too easy to leave “dangling” resources lying around (robustness)
Forget Homogeneity!
• Trying to force homogeneity on users is futile. Everyone has their own preferences, sometimes even dogma.
• The Internet provides the model…
What Does the Globus Toolkit Cover?
GoalToday
Theory -> Practice
building a grid(in practice)
Methodology• Building a Grid system or application is currently an
exercise in software integration.– Define user requirements
– Derive system requirements or features
– Survey existing components
– Identify useful components
– Develop components to fit into the gaps
– Integrate the system
– Deploy and test the system
– Maintain the system during its operation
• This should be done iteratively, with many loops and eddys in the flow.
How it Really Happens
WebBrowser
ComputeServer
DataCatalog
DataViewer
Tool
Certificateauthority
ChatTool
CredentialRepository
WebPortal
ComputeServer
Resources implement standard access & management interfaces
Collective services aggregate &/or
virtualize resources
Users work with client applications
Application services organize VOs & enable
access to other services
Databaseservice
Databaseservice
Databaseservice
SimulationTool
Camera
Camera
TelepresenceMonitor
RegistrationService
How it Really Happens(without Globus)
WebBrowser
ComputeServer
DataCatalog
DataViewer
Tool
Certificateauthority
ChatTool
CredentialRepository
WebPortal
ComputeServer
Resources implement standard access & management interfaces
Collective services aggregate &/or
virtualize resources
Users work with client applications
Application services organize VOs & enable
access to other services
Databaseservice
Databaseservice
Databaseservice
SimulationTool
Camera
Camera
TelepresenceMonitor
RegistrationService
A
B
C
D
E
Application Developer
10
Off the Shelf 12
Globus Toolkit 0
Grid Community
0
How it Really Happens(with Globus)
WebBrowser
ComputeServer
GlobusMCS/RLS
DataViewer
Tool
CertificateAuthority
CHEF ChatTeamlet
MyProxy
CHEF
ComputeServer
Resources implement standard access & management interfaces
Collective services aggregate &/or
virtualize resources
Users work with client applications
Application services organize VOs & enable
access to other services
Databaseservice
Databaseservice
Databaseservice
SimulationTool
Camera
Camera
TelepresenceMonitor
Globus IndexService
GlobusGRAM
GlobusGRAM
GlobusDAI
GlobusDAI
GlobusDAI
Application Developer
2
Off the Shelf 9
Globus Toolkit 4
Grid Community
4
What Is the Globus Toolkit?
• The Globus Toolkit is a collection of solutions to problems that frequently come up when trying to build collaborative distributed applications.
• Not turnkey solutions, but building blocks and tools for application developers and system integrators.– Some components (e.g., file transfer) go farther than others (e.g.,
remote job submission) toward end-user relevance.
• To date (v1.0 - v4.0), the Toolkit has focused on simplifying heterogeneity for application developers.
• The goal has been to capitalize on and encourage use of existing standards (IETF, W3C, OASIS, GGF).– The Toolkit also includes reference implementations of new/proposed
standards in these organizations.
How To Use the Globus Toolkit
• By itself, the Toolkit has surprisingly limited end user value.– There’s very little user interface material there.– You can’t just give it to end users (scientists, engineers,
marketing specialists) and tell them to do something useful!
• The Globus Toolkit is useful to application developers and system integrators. – You’ll need to have a specific application or system in
mind.– You’ll need to have the right expertise.– You’ll need to set up prerequisite hardware/software.– You’ll need to have a plan.
Data Management
SecurityCommonRuntime
Execution Management
Information Services
Web Services
Components
Non-WS
Components
Pre-WSAuthenticationAuthorization
GridFTP
GridResource
Allocation Mgmt(Pre-WS GRAM)
Monitoring& Discovery
System(MDS2)
C CommonLibraries
GT2
WSAuthenticationAuthorization
ReliableFile
Transfer
OGSA-DAI[Tech Preview]
GridResource
Allocation Mgmt(WS GRAM)
Monitoring& Discovery
System(MDS4)
Java WS Core
CommunityAuthorization
ServiceGT3
ReplicaLocationService
XIO
GT3
CredentialManagement
GT4
Python WS Core[contribution]
C WS Core
CommunitySchedulerFramework
[contribution]
DelegationService
GT4
Globus Toolkit Components
Incr
ease
d fu
nctio
nalit
y,st
anda
rdiz
atio
n
Customsolutions
1990 1995 2000 2005
Open GridServices Arch
Real standardsMultiple implementations
Web services, etc.
Managed sharedvirtual systems
Computer science research
Globus Toolkit
Defacto standardSingle implementation
Internetstandards
The Emergence ofOpen Grid Standards
2010
Grid Communities
• Global Grid Forum– Standards, information exchange, advocacy– 1000+ participants in tri-annual meetings
• Application communities– E.g., physics, earthquake engineering,
biomedical, etc.
• Software development and support– NSF Middleware Initiative, UK eScience,
Globus Toolkit, EGEE, …
Grid Communities & Technologies
• Yesterday– Small, static communities, primarily in science– Focus on sharing of computing resources– Globus Toolkit as technology base
• Today– Larger communities in science; early industry– Focused on sharing of data and computing– Open Grid Services Architecture
• Tomorrow– Large, dynamic, diverse communities that share a wide variety of
services, resources, data– Challenging computer science research issues
Grid Dynamics:Vision vs. Reality
• Vision: On-demand access to computing– New communities form easily– On-demand resources from providers– Adapt easily to new missions, requirements
• Reality: Much manual configuration, e.g.:– Manually deployed services on dedicated hardware– Manually maintained access control lists– Sysadmin-maintained allocation policies– Human-mediated resource reservation
Reading Sources
• http://www-fp.mcs.anl.gov/~foster/talks.htm
• http://www.globus.org/
• The Grid Book
• (other links on the course page)