Poster: Retro: an automated, application-layer record and replay for android

Abstract

Today's mobile applications operate in a diverse set of environments, where it is difficult for a developer to know beforehand what conditions his or her application will be put under. For example, once deployed on an online application store, an application can be downloaded on different types of hardware, ranging from budget smartphones to high-end tablets. In addition, network conditions can vary widely from Wi-Fi to 3G to 4G. Mobile applications also need to co-exist with other applications that compete for resources at different times. Due to this diverse set of operating conditions, it is difficult to understand what problems are occurring in the wild for mobile applications. Moreover, it is even more difficult to reproduce problems in a lab environment where developers can debug the problems. Some platforms support bug reports and stack traces, but they are inadequate in scenarios when operating conditions and inputs are not consistent. To address these issues, we propose Retro, an automated, application-layer record and replay system for Android. Unlike previous record and replay systems, Retro aims to support mobile Android applications with three features. First, Retro provides an automated instrumentation framework that transforms a regular Android application into a traceable application. This means that Retro does not require any change in the Android platform; thus, it enables developers to distribute instrumented applications via online application stores. Through the instrumentation, Retro records application-layer events such as click events, sensor readings, method calls, and return values. In order to reduce the overhead of logging, Retro also uses a selective logging mechanism that decides which event types to log at runtime. Second, Retro provides a replayer that a developer can use in a lab environment to faithfully replay a recorded run. To maximize the ease of use, Retro seamlessly integrates this replay functionality into Android's existing development workflow by adding the replayer into the Android platform. This means that a developer can replay using a regular phone as well as an emulator. Also, Retro provides a VCR-like interface for replaying that is capable of forwarding and rewinding executions. Third, Retro examines Android-specific issues in enabling record and replay and incorporates design choices that are tailored towards Android. The goal for doing this is efficiency and faithfulness; by examining Android-specific issues, Retro can provide efficient recording and replaying functionalities as well as faithfulness in replaying.