Proactive Detection of Software Aging Mechanisms in Performance Critical Computers

1. Proactive Detection of Software Aging Mechanisms in Performance Critical Computers ParitoshSumrao 10IT20F MTech IT

2. Software aging • phenomenon in which the state of the software system degrades with time. • can include memory leaks, unreleased file locks, accumulation of un terminated threads, data corruption/round-off accrual, file space, fragmentation, shared memory pool latching, and others. • Solution: Software rejuvenation. • Time based • Prediction based.

3. Diagnostic Procedure Overview

4. Diagnostic Procedure Overview cont.. • Training data should be exhaustive and correct. • Procedure for fault detection. • ‘Residual’ for all signal values is computed. • Sequential Probability Ratio Test (SPRT) technique is employed to find the anomaly.

5. SPRT (Sequential Probability Ratio Test ) • The sequential probability ratio test (SPRT) is a specific sequential hypothesis test. • The SPRT technique is a better because it is sensitive not only to disturbances in the signal mean, but also to very subtle changes in the statistical quality (variance, skew ness, bias) of the signals.

6. Performance parameters

7. Fig: A: Estimate.. B. Residual .and C: Alarm

8. References • “Proactive Detection of Software Aging Mechanisms in Performance Critical Computers” by Kenny C. Gross, Vatsal Bhardwaj, Randy Bickford • www.en.wikipedia.org/wiki/Sequential_probability_ratio_test , SPRT

9. Thank you !!