achieving application performance on the information power grid francine berman u. c. san diego and...
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Achieving Application Performance on the
Information Power Grid
Francine Berman
U. C. San Diego and NPACI
IPG = “Distributed Computer”
• comprising
– clusters of workstations
– MPPs
– remote instruments
– visualization sites
– data archives
• for users, performance is key criteria in evaluating platform
Program Performance
• Current grid programs achieve performance
by – dedicating resources– careful staging of computation and data– considerable coordination
• It must be possible to achieve program
performance on the IPG by ordinary users on
ordinary days ...
Achieving Performance
• On ordinary days, many users share system resources
– load and availability of resources vary
– application behavior hard to predict
– poor predictions make scheduling hard
• Challenge: Develop application schedules which can leverage deliverable performance of system at execution time.
Whose Job Is It?
• Application scheduling can be performed by many entities
– Resource scheduler
– Job Scheduler
– Programmer or User
– System Administrator
– Application Scheduler
Scheduling and Performance
• Goal of scheduling application is to promote application performance
• Achieving application performance can conflict with achieving performance for other system components
– Resource Scheduler -- perf measure is utilization
– Job Scheduler -- perf measure is throughput
– System Administrator -- focuses on system perf
– Programmer or User -- may miss most current info
– Application Scheduler -- can access most current info
• Everything in the system is evaluated in terms of its impact on the application.
– performance of each system component can be considered as a measurable quantity
– forecasts of quantities relevant to the application can be manipulated to determine schedule
• This simple paradigm forms the basis for AppLeS.
Self-Centered Scheduling
AppLeS
Joint project with Rich Wolski
• AppLeS = Application-Level Scheduler
• Each application has its own self-centered AppLeS
• Schedule achieved through– selection of potentially efficient resource sets
– performance estimation of dynamic system parameters and application performance for execution time frame
– adaptation to perceived dynamic conditions
AppLeS Architecture• AppLeS incorporates
– application-specific information– dynamic information– prediction
• Schedule developed to optimize user’s performance measure– minimal execution time
– turnaround time = staging/waiting time + execution time
– other measures: precision, resolution, speedup, etc.
NWS(Wolski)
UserPrefs
AppPerf
Model
PlannerResource Selector
Application
Act.IPG resources/
infrastructure
Network Weather Service (Wolski)
• The NWS provides dynamic resource information for AppLeS
• NWS – monitors current system
state
– provides best forecast of resource load from multiple models
Sensor Interface
Reporting Interface
Forecaster
Model ModelModel
SARA: An AppLeS-in-Progress
• SARA = Synthetic Aperture Radar Atlas
– application developed at JPL and SDSC
• Goal: Assemble/process files for user’s desired image
– thumbnail image shown to user
– user selects desired bounding box within image for more detailed viewing
– SARA provides detailed image in variety of formats
Simple Sara• Focuses on obtaining remote data quickly• Code developed by Alan Su
ComputeServer
DataServer
DataServer
DataServer
Computation servers
and data servers are
logical entities, not
necessarily different
nodes
Network shared by variable number of users
Computation assumed to be done at compute servers
Simple SARA AppLeS
• Focus on resource selection problem: Which site can deliver data the fastest?
– Data for image accessed over shared networks
– Data sets 1.4 - 3 megabytes, representative of SARA file sizes
– Servers used for experiments• lolland.cc.gatech.edu
• sitar.cs.uiuc
• perigee.chpc.utah.edu
• mead2.uwashington.edu
• spin.cacr.caltech.edu
via vBNS
via general Internet
Which is “Closer”?
• Sites on the east coast or sites on the west coast?
• Sites on the vBNS or sites on the general Internet?
• Consistently the same site or different sites at different times?
Which is “Closer”?
• Sites on the east coast or sites on the west coast?
• Sites on the vBNS or sites on the general Internet?
• Consistently the same site or different sites at different times?
Depends a lot on traffic ...
Preliminary Results• Experiment with larger data set (3 Mbytes)
• During this time-frame, general Internet provides data mostly faster than vBNS
• Experiment with smaller data set (1.4 Mbytes)• During this time frame, east coast sites provide
data mostly faster than west coast sites
More Preliminary Results
Distributed Data Applications
• SARA representative of larger class of distributed data applications
• Simple SARA template being extended to accommodate– replicated data sources– multiple files per image– parallel data acquisition– intermediate compute sites– web interface, etc.
SARA AppLeS -- Phase 2
Client, servers are“logical” nodes, which servers should the client use?
Client Comp.Server
Comp.Server
Comp.Server
DataServer
DataServer
DataServer
DataServer
. . .
Move the computationor move the data?
Computation, dataservers may “live” atthe same nodes
Data serversmay access thesame storage media. How long will data accesstake when data isneeded?
A Bushel of AppLeS … almost
• During the first “phase” of the project, we’ve focused on getting experience building AppLeS
– Jacobi2D, DOT, SRB, Simple SARA, Genetic Algorithm, Tomography, ...
• Using this experience, we are beginning to build AppLeS “templates”/tools for
– master/slave applications– parameter sweep applications– distributed data applications– proudly parallel applications, etc.
• What have we learned ...
Lessons Learned from AppLeS
• Knowing something about performance predictions can improve scheduling
Lessons Learned from AppLeS
• Performance of scheduling policy sensitive to application, data, and system characteristics
A First IPG AppLeS
• Focus on class of parameter sweep applications
• Building AppLeS template for INS2D that can be used with other applications from class
• AppLeS INS2D scheduler
– first phase focuses on interactive clusters
– second phase will target clusters and batch-scheduled platforms
– goal is to minimize turnaround time
Parameter Sweep AppLeS Architecture
• Being developed by Dmitrii Zagorodnov• AppLeS schedules work on interactive resources• AppLeS tuned to leverage underlying resource
management system
AppLe S
AP
I
Resources
App-specific
case
gen.
Exp
Act
ActSched.
Act
Exp Exp
INS2D AppLeS Project Goals
• Complete design and deployment of INS2D AppLeS for interactive cluster– focus on socket design for first phase
• Conduct experiments to assess AppLeS performance on interactive cluster and to compare with batch system performance
• Expand INS2D AppLeS to target both batch and interactive systems – target to evolving IPG resource management
system
AppLeS and the IPG
Usability,Integration
development ofbasic IPG infrastructure
Performance
“grid-aware”programming
Short-term Medium-term Long-term
Application schedulingResource schedulingThroughput scheduling
Multi-schedulingResource economy
Integration of schedulers and other tools, performanceinterfacesYou are
here
Integration of multiplegrid constituencies
architectural models whichsupport multiple constituencies
automation of programexecution
Project Information• Thanks to NSF, NPACI,
Darpa, DoD, NASA
• AppLeS Corps:– Francine Berman
– Rich Wolski
– Walfredo Cirne
– Marcio Faerman
– Jaime Frey
– Jim Hayes
– Graziano Obertelli
• AppLeS Home Page: http://www-cse.ucsd.edu/groups/hpcl/apples.html
– Jenny Schopf
– Gary Shao
– Neil Spring
– Shava Smallen
– Alan Su
– Dmitrii Zagorodnov