On the use of delta debugging to reduce recordings and facilitate debugging of web applications

Recording the sequence of events that lead to a failure of a web application can be an effective aid for debugging. Nevertheless, a recording of an event sequence may include many events that are not related to a failure, and this may render debugging more difficult. To address this problem, we have adapted Delta Debugging to function on recordings of web applications, in a manner that lets it identify and discard portions of those recordings that do not influence the occurrence of a failure. We present the results of three empirical studies that show that (1) recording reduction can achieve significant reductions in recording size and replay time on actual web applications obtained from developer forums, (2) reduced recordings do in fact help programmers locate faults significantly more efficiently as, and no less effectively than non-reduced recordings, and (3) recording reduction produces even greater reductions on larger, more complex applications.