Almost every Android user has unsatisfying experiences regarding responsiveness, in particular Application Not Responding (ANR) and System Not Responding (SNR) that directly disrupt user experience. Unfortunately, the community have limited understanding of the prevalence, characteristics, and root causes of unresponsiveness. In this paper, we make an in-depth study of ANR and SNR at scale based on fine-grained system-level traces crowdsourced from 30,000 Android systems. We find that ANR and SNR occur prevalently on all the studied 15 hardware models, and better hardware does not seem to relieve the problem. Moreover, as Android evolves from version 7.0 to 9.0, there are fewer ANR events but more SNR events. Most importantly, we uncover multifold root causes of ANR and SNR and pinpoint the largest inefficiency which roots in Android's flawed implementation of Write Amplification Mitigation (WAM). We design a practical approach to eliminating this largest root cause; after large-scale deployment, it reduces almost all (>99%) ANR and SNR caused by WAM while only decreasing 3% of the data write speed. In addition, we document important lessons we have learned from this study, and have also released our measurement code/data to the research community.
|Original language||English (US)|
|Title of host publication||Proceedings of the 26th Annual International Conference on Mobile Computing and Networking, MobiCom 2020|
|Publisher||Association for Computing Machinery|
|Number of pages||11|
|State||Published - Apr 16 2020|
|Event||26th Annual International Conference on Mobile Computing and Networking, MobiCom 2020 - London, United Kingdom|
Duration: Sep 21 2020 → Sep 25 2020
|Name||Proceedings of the Annual International Conference on Mobile Computing and Networking, MOBICOM|
|Conference||26th Annual International Conference on Mobile Computing and Networking, MobiCom 2020|
|Period||9/21/20 → 9/25/20|
Bibliographical noteFunding Information:
We sincerely thank the anonymous reviewers for their insightful and detailed comments, as well as the shepherd for guiding us through the revision process. This work is supported in part by the National Key R&D Program of China under grant 2018YFB1004700, the National Natural Science Foundation of China (NSFC) under grants 61822205, 61632020 and 61632013, and the Beijing National Research Center for Information Science and Technology (BNRist).
© 2020 ACM.
- application not responding (ANR)
- system not responding (SNR)
- write amplification mitigation (WAM)