1. 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 Chrulkiewicz CS-575 Position Paper Presentation Fall 2007

2. 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.gif http://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

3. 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

4. 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

5. 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 OCUK Predictor@home total credit. Go team!

6. 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

7. 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

8. 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

9. 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

10. Questions? Image: http://www.grid.phys.uvic.ca/ Geoff Oxholm Beata Churkiewicz