Multiscale visual comparison of execution traces

Understanding the execution of programs by means of program traces is a key strategy in software comprehension. An important task in this context is comparing two traces in order to find similarities and differences in terms of executed code, execution order, and execution duration. For large and complex program traces, this is a difficult task due to the cardinality of the trace data. In this paper, we propose a new visualization method based on icicle plots and edge bundles. We address visual scalability by several multiscale visualization metaphors, which help users navigating from the main differences between two traces to intermediate structural-difference levels, and, finally fine-grained function call levels. We show how our approach, implemented in a tool called TRACEDIFF, is applicable in several scenarios for trace difference comprehension on real-world trace datasets.