ConfTest: Generating Comprehensive Misconfiguration for System Reaction Ability Evaluation

Misconfigurations are not only prevalent, but also costly on diagnosing and troubleshooting. Unlike software bugs, misconfigurations are more vulnerable to users' mistakes. Improving system reaction to misconfigurations would ease the burden of users' diagnoses. Such effort can greatly benefit from a comprehensive study of system reaction ability towards misconfigurations based on errors injection method. Unfortunately, few such studies have achieved the above goal in the past, primarily because they fail to provide rich error types or only rely on generic alternations to generate misconfigurations. In this paper, we studied 8 mature opensource and commercial software and summarized a fine-grained classification of option types. On the basis of this classification, we could extract syntactic and semantic constraints of each type to generate misconfigurations. We implemented a tool named ConfTest to conduct misconfiguration injection and further analyze system reaction abilities to various of misconfigurations. We carried out comprehensive analyses upon 4 open-source software systems. Our evaluation results show that our option classification covers over 96% of 1582 options from Httpd, Yum, PostgreSQL and MySQL.Our constraint is more fined-grained and the accuracy is more than 90% of of real constraints through manual verification. We compared the capability in finding bad system reactions between ConfTest and ConfErr, showing that the ConfTest can find nearly 3 times the bad reactions found by ConfErr.