Understanding Bohr-Mandel bugs through ODC Triggers and a case study with empirical estimations of their field proportion
Ram Chillarege , Chillarege Inc.
IEEE Third International Workshop on Software Aging and Rejuvenation, ISSRE Conference, pp. 7-13, 2011
We discuss the Bohr-Mandel theory of bugs and argue that a greater insight and differentiation is possible through the use of ODC Triggers. In some respects, since the current definitions do not leverage the concept of triggers, there is confusion as to what they are. We conduct a case study to measure the proportion of Bohr-Mandel bugs using ODC Triggers. Our case study results are compared to the JPL-NASA study on Bohr-Mandel bugs. Our estimates of Mandelbug proportions ranges (~20-40% range) are very comparable to those found in the JPL-NASA study. We find that the Mandelbug presence is uniform across multiple impact groups and components of the product. We found that in our case study, as the product ages in the field, the proportion of Mandel bugs seemed to drop. While this finding cannot be generalized, it does alert us to watch this phenomenon in other case studies. However, given the numbers it is clear that methods to alleviate the impact of Mandelbugs early in the lifetime of a product will be of significant value.
This is a technical talk on the Bohr-Mandel bug theory, with experimental data that is compared to the results published by the NASA study on this topic.
Date: Thursday, December 1, 2011 1:00 PM Location: Hiroshima, Japan Conference Program: The 3rd International Workshop on Software Aging and Rejuvenation Program
Abstract
This paper uses ODC Triggers as a means to estimate the Bohr-Mandel bug proportions from a software product in production. Specifically, the contributions are:
- A conceptual articulation of how ODC Triggers can differentiate between Bohr and Mandel bugs
- A grouping of triggers to estimate the proportion of Bohr-Mandel bugs in the field.
- A case study that estimates Mandelbug proportions to range ~20%-40% which is comparable to the JPLNASA empirical study.
- A measure of the distribution of Mandelbugs across components, impact groups and time.
- Creates a discussion, and raises questions in greater depth on the Bohr-Mandel definitions, implications, features and manifestations.
INTRODUCTION
The subject of Bohrbugs, Mandelbugs (and/or Heisenbugs) is of interest to a few communities in software engineering. While these ideas have been around for a while, its importance grows as more software products ship with rejuvenation methods and tools. Also, large software service providers of cloud computing infrastructure need greater sophistication in the application of fault-tolerant methods at higher levels of abstraction. Thus, our need for a greater understanding of the underlying fault and failure phenomenons is vital.