Resource Management in Volunteer Computing Grids

An analysis of the different approaches to maximizing

throughput on a BOINC grid

Presented by Geoffrey Oxholm and Beata ChrulkiewiczCS-575 Position Paper Presentation Fall 2007

Volunteer Grids• A Type of Grid Computer

– Decentralized, volunteer nodes• Supercomputing for free

– 1.1 PetaFLOPS vs. 360 TeraFLOPS

Image: http://www.di.unipi.it/groups/architetture/images/grid.gifhttp://holistic.com.mt/h/?Page=Article&Ref=107

• Unreliable Nodes– Users can disconnect their computers anytime– Amount of donated resources is subject to change– Evil jerks can upload malicious data

Berkeley Open Infrastructure for Network Computing

• Duplicate work to ensure validity– R – The “Redundancy Factor”

• Validate computation results. If the validation fails, repeat computation. – Validation Methods:

• Majority Voting– More than R/2 nodes must agree

• M-First Voting– First M nodes must agree

Image: http://en.wikipedia.org/wiki/Image:BOINC_logo_July_2007.png

Success and Limitations of BOINC

• With proper configuration high throughput can be achieved

• Still quite difficult to get volunteers

• Proper configuration is difficult• Fixed configurations can not

account for constantly changing grid characteristics

Image: http://www.baseacid.com/imagesRR/workBand.jpg

Fix: User Encouragement Feedback and Reward

• Each node generates statistics• Teams can be formed• Sense of pride in commitment• Encourages users to donate more time, resources

Image: http://teamocuk.com/cprojectcred1.php?p=PAH

Team OCUKPredictor@home

total credit.

Go team!

Fix: Maximizing Configuration Through Usage Simulation

• Enumerate a set of possible configurations• Test configurations in a fraction of the time • Avoid disturbing volunteers by simulating• Zero in on an effective configuration

Image: http://www.cyberroach.com/tron/tron3_circuit.jpg

Fix: Dynamic Redundancy Through Reliability Prediction

• Wait for a minimum number of nodes before assigning work

• Choose nodes which have higher reliability• Higher reliability means less need for redundancy

• Successful completion yields higher reliability rating for the node

Image: http://image.compusa.com/prodimages/44/8537c95c-8027-4840-b976-67deb0690e13.gif

Evaluation• User Encouragement

– Encourages cheating– Does nothing to maximize

efficient use of resources• Usage Simulation

– Still requires researchers to configure system– Static configuration fails to match dynamic grid

• Reliability Rating– Subject to further exploitation– Further minimizes the value of slow nodes, working

against incentives

Image: GPL Licensed

Conclusion• Build on existing methods

– Continue to encourage users– Create a starting point by using simulation– Update reliability system to avoid conflict

with system of incentives

• Develop new technologies– Blacklist malicious nodes– Develop a more comprehensive reliability system

which uses past schedules to predict future availability

Image: http://pixels.dessgeega.com/wp-content/uploads/2006/10/organize_big.gif

Questions?

Image: http://www.grid.phys.uvic.ca/

Geoff Oxholm Beata Churkiewicz