Ocasta: Clustering Configuration Settings For Error Recovery
This addresses configuration error recovery in computer systems, particularly for errors requiring multiple setting fixes, offering a practical tool for both expert and non-expert users, though it is incremental as it builds on existing work targeting single-setting errors.
The paper tackles the problem of diagnosing and repairing configuration errors that involve multiple interdependent settings, presenting Ocasta, a method that clusters dependent settings based on application access patterns and achieves 88.6% accuracy in cluster identification, successfully repairing all 16 real-world errors in an average of 11 minutes with minimal user input.
Effective machine-aided diagnosis and repair of configuration errors continues to elude computer systems designers. Most of the literature targets errors that can be attributed to a single erroneous configuration setting. However, a recent study found that a significant amount of configuration errors require fixing more than one setting together. To address this limitation, Ocasta statistically clusters dependent configuration settings based on the application's accesses to its configuration settings and utilizes the extracted clustering of configuration settings to fix configuration errors involving more than one configuration settings. Ocasta treats applications as black-boxes and only relies on the ability to observe application accesses to their configuration settings. We collected traces of real application usage from 24 Linux and 5 Windows desktops computers and found that Ocasta is able to correctly identify clusters with 88.6% accuracy. To demonstrate the effectiveness of Ocasta, we evaluated it on 16 real-world configuration errors of 11 Linux and Windows applications. Ocasta is able to successfully repair all evaluated configuration errors in 11 minutes on average and only requires the user to examine an average of 3 screenshots of the output of the application to confirm that the error is repaired. A user study we conducted shows that Ocasta is easy to use by both expert and non-expert users and is more efficient than manual configuration error troubleshooting.