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Joseph StithTrust But Verify

December 2006

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BackgroundiMPACT Data Center

Project• Platform imbedded

temperature sensors• Used by

– Visualization– Decision making on

scheduling future jobs

8 minute timer

Pole sensors

Visualization

Decision Making

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Cabinets(Racks)

TraditionalServers .

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Blade Systems

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Why?Coordinated Power, Fans, Network, iLO, etc

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Problem Statement1. Visualization software requires ALL

data points to be present2. Platform sensors have high

reliability, but across an entire data center failures will occur over time

– Multiplication effect– Shut systems down

3. Wireless and/or inexpensive sensors less reliable

Phidget

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Solution1. Validate sensor data based on

Quasi-Redundant neighbors

2. Reconstruct missing (or previously invalidated) data based on reliable Quasi-Redundant neighbors

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State of the TechnologyMuch sensor reliability effort is focused on in-

network processing to eliminate erroneous data to save energy before data gets to sync. e.g. Ye.1

This project is single hop from sync.

TIBFIT – Trust Index Based Fault Tolerance2

Failures tend not to be random over time. Recall individual sensor reliability history and make decisions be weighted

Minimal Diagnosis – Identify conflicting sets then identify minimal sensors that could be failing to remove conflicts.6

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State of the Technology1. Diagnosability

Degree3; 0-1 IP2. Bayesian Principle

Component Analysis (BPCA)4

3. Local Least Squares5

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Solution• Utilize all Platform and

External sensors• Utilize

– Minimal Diagnosis– 0-1 Integer Problem– TIBFIT– Weighted Averages

• Implementation– Visual Basic– Interface to sensors:

Files

8 minute timer

Pole sensors

Visualization

Decision Making

Verify SensorsVerify Sensors

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Sensors0 Housing-Right

1 Housing-Center

2 Housing-Left

3 Switch-1

4 Switch-2

5 Switch-3

6 PS-1

7 PS-2

8 PS-3

9 PS-4

10 Ambient

11 Cab-Back-Right

12 Cab-Back-Right-Mid

13 Cab-Back-Middle

14 Cab-Back-Left-Mid

15 Cab-Back-Left

16 Cab-Front-Right

17 Cab-Front-Middle

18 Cab-Front-Left

012

45

6789

10

1112131415

161718

3

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10/25 Turn in phase II Done 10/25

TBD Receive phase II feedback Done 10/30

11/1 Turn in Phase II, Version 2 Done 11/1

11/6 Get Visual Studio functioning with a “Hello World” application. Done 11/5

11/6 Get skeleton program working with:a. Main programb. Stub functions

Done 11/7

11/13 Get final specs from IMPACT on:a. unreliable data formatb. reliable data formatc. Presumption output will match current reliable data format.d. Configuration information on sensors (e.g., physical location/relative locations)

Overdue

11/20 Develop configuration file based on sensor relative locations Done 11/26

11/27 Develop rev 1 validation subroutine (include configuration and TIBFIT) and integrate with stubs

11/27 Develop rev 1 reconstruction algorithm; integrate with stubs

11/27 Test integrated environment with various simulated data flows.

12/4 Implement with IMPACT actual data flow.

12/11 Implement with IMPACT actual data flow with out of control sensors)Update Schedule: Due 12/4

12/13 Turn in final report/presentationUpdate Schedule:1. PowerPoint Presentation: Due 11/27 Noon2. Report Due: 12/43. Present to class: 12/44. Demonstrate project: 12/5

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Config File0|Housing-Right|16|cooler|10|cooler|1|peer|3|warmer|6|warmer1|Housing-Center|17|cooler|10|cooler|2|peer|0|peer|4|warmer

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Questions

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References1. F. Ye, H. Luo, S. Lu, and L. Zhang, “Statistical En-route

Filtering of injected False Data in Sensor Networks,” IEEE Infocom ’04, March 2004

2. Mark D. Krasniewski, Padma Varadharajan, Bryan Rabeler, Saurabh Bagchi, Y. Charlie Hu: TIBFIT: Trust Index Based Fault Tolerance for Arbitrary Data Faults in Sensor Networks. DSN 2005: 672-681, 2005 International Conference on Dependable Systems and Networks (DSN 2005), 28 June - 1 July 2005, Yokohama, Japan, Proceedings. IEEE Computer Society 2005, ISBN 0-7695-2282-3

3. Fijany, Amir, and Farrokh Vatan, A New Efficient Algorithm for Analyzing and Optimizing the System of Sensors, IEEEAC Paper 1568, Dec 20, 2005

4. Figure: http://www.cis.syr.edu/~wedu/Research/paper/privacy_sigmod05.ppt

5. Figure: http://zoonek2.free.fr/UNIX/48_R/10.html