Defect Analysis and Reliability Assessment for Transactional Web Applications

In this research, we analyze defects collected from different failure sources and use it for reliability assessment. Failure is the inability of a system or component to perform its required functions within specified performance requirements. Reliability is the probability of failure-free operations, and it is one of the most important quality attribute for the users of web applications. Reliability analysis and modeling can help Web service providers to assess current reliability, predict future reliability, and quantify potential improvement to reach reliability target. The failure information and the related workload measurements are required input for various reliability models under variable work load such as modeling transactional web applications. In this paper, we used session tracking data in addition to web server logs to characterize and measure the variable application workload. Session data provides accurate measurements of web applications' usage time such as the number of transactions that are required for reliability analysis. In addition to web failures recorded in web logs and defect tracking system, we also considered failures from the server side application error logs to quantify unique failures that occur on the web server. We applied different reliability assessment approaches covering time domain and input domain on data from our case study application and demonstrated the applicability and effectiveness of our approach.