Performance issues compromise the response time and resource consumption of a software system. Modern software systems use issue tracking systems to manage all kinds of issue reports, including performance issues. The problem is that performance issues are often not explicitly tagged. The tagging mechanism, if exists, is completely voluntary, depending on the project’s convention and on submitters’ discipline. For example, the performance tag rate in Apache’s Jira system is below 1%. This paper contributes a hybrid classification approach that combines linguistic patterns and machine/deep learning techniques to automatically detect performance issue reports. We manually analyzed 980 real-life performance issue reports and derived 80 project-agnostic linguistic patterns that recur in the reports. Our approach uses these linguistic patterns to construct the sentence-level and issue-level learning features for training effective machine/deep learning classifiers. We test our approach on two separate datasets, each consisting of 980 unclassified issue reports, and compare the results with 31 baseline methods. Our approach can reach up to 83% precision and up to 59% recall. The only comparable baseline method is BERT, which is still 25% lower in the F1-score.

Empirical experience regarding how real-life performance issues are caused and resolved can provide valuable insights for practitioners to effectively and efficiently prevent, detect, and fix performance issues. Prior work shows that most performance issues have their roots in poor architectural decisions. This paper contributes a large scale empirical study of 192 real-life performance issues, with an emphasis on software design. First, this paper contributes a holistic view of eight common root causes and typical resolutions that recur in different projects, and surveyed existing literature, in particular, tools, that can detect and fix each type of performance issue. Second, this study is first-of-its-kind to investigate performance issues from a design perspective. In the 192 issues, 33% required design-level optimization, i.e. simultaneously revising a group of related source files for resolving the issues. We reveal four design-level optimization patterns, which have shown different prevalence in resolving different root causes. Finally, this study investigated the Return on Investment for addressing performance issues, to help practitioners choose between localized or design-level optimization resolutions, and to prioritize issues due to different root causes.