Locating performance improvement opportunities in an industrial software-as-a-service application

The goal of performance maintenance is to improve the performance of a software system after delivery. As the performance of a system is often characterized by unexpected combinations of metric values, manual analysis of performance is hard in complex systems. In this paper, we extend our previous work on performance anomaly detection with a technique that helps performance experts locate spots - so-called performance improvement opportunities (PIOs) -, for possible performance improvements. PIOs give performance experts a starting point for performance improvements, e.g., by pinpointing the bottleneck component. The technique uses a combination of association rules and several visualizations, such as heat maps, which were implemented in an open source tool called Wedjat. In this paper, we evaluate our technique and Wedjat in a field user study with three performance experts from industry using data from a large-scale industrial application. From our field study we conclude that our technique is useful for speeding up the performance maintenance process and that heat maps are a valuable way of visualizing performance data.