Libreplay: Deterministic replay for bug hunting in sensor networks

Abstract

Bug hunting in sensor networks is challenging: Bugs are often prompted by a particular, complex concatenation of events. Moreover, dynamic interactions between nodes and with the environment make it time-consuming to track and reproduce a bug. We introduce LibReplay to ease bug hunting in sensor networks: it provides (1) lightweight and flexible logging and (2) deterministic replay. LibReplay logs function calls to and from the application or another code of interest. It enables deterministic replay of execution traces in a controlled environment such as a full-system simulator. This allows the user to benefit from wellestablished debugging tools such as stepping through code, breakpoints, or watchpoints. We show that the lightweight architecture of LibReplay provides the benefits of replay debugging at an efficiency that is comparable to traditional logging tools, which commonly do not allow replay debugging.