TY - GEN
T1 - Towards Web-based Delta Synchronization for Cloud Storage Services
AU - Xiao, He
AU - Li, Zhenhua
AU - Zhai, Ennan
AU - Xu, Tianyin
AU - Li, Yang
AU - Liu, Yunhao
AU - Zhang, Quanlu
AU - Liu, Yao
N1 - Funding Information:
We thank the anonymous reviewers for their positive and constructive comments. Besides, we appreciate the valuable guidance and detailed suggestions from our shepherd, Vasily Tarasov, during the revision of the paper. In addition, we thank Yonghe Wang for helping with some measurements during the preparation of the paper. This work is supported by the High-Tech R&D Program of China (“863–China Cloud” Major Program) under grant 2015AA01A201, the NSFC under grants 61471217, 61432002, 61632020 and 61472337. Ennan Zhai is partly supported by the NSF under grants CCF-1302327 and CCF-1715387.
PY - 2018
Y1 - 2018
N2 - Delta synchronization (sync) is crucial for network-level efficiency of cloud storage services. Practical delta sync techniques are, however, only available for PC clients and mobile apps, but not web browsers—the most pervasive and OS-independent access method. To understand the obstacles of web-based delta sync, we implement a delta sync solution, WebRsync, using state-of-the-art web techniques based on rsync, the de facto delta sync protocol for PC clients. Our measurements show that WebRsync severely suffers from the inefficiency of JavaScript execution inside web browsers, thus leading to frequent stagnation and even hanging. Given that the computation burden on the web browser mainly stems from data chunk search and comparison, we reverse the traditional delta sync approach by lifting all chunk search and comparison operations from the client side to the server side. Inevitably, this brings considerable computation overhead to the servers. Hence, we further leverage locality-aware chunk matching and lightweight checksum algorithms to reduce the overhead. The resulting solution, WebR2sync+, outpaces WebRsync by an order of magnitude, and is able to simultaneously support 6800–8500 web clients’ delta sync using a standard VM server instance based on a Dropbox-like system architecture.
AB - Delta synchronization (sync) is crucial for network-level efficiency of cloud storage services. Practical delta sync techniques are, however, only available for PC clients and mobile apps, but not web browsers—the most pervasive and OS-independent access method. To understand the obstacles of web-based delta sync, we implement a delta sync solution, WebRsync, using state-of-the-art web techniques based on rsync, the de facto delta sync protocol for PC clients. Our measurements show that WebRsync severely suffers from the inefficiency of JavaScript execution inside web browsers, thus leading to frequent stagnation and even hanging. Given that the computation burden on the web browser mainly stems from data chunk search and comparison, we reverse the traditional delta sync approach by lifting all chunk search and comparison operations from the client side to the server side. Inevitably, this brings considerable computation overhead to the servers. Hence, we further leverage locality-aware chunk matching and lightweight checksum algorithms to reduce the overhead. The resulting solution, WebR2sync+, outpaces WebRsync by an order of magnitude, and is able to simultaneously support 6800–8500 web clients’ delta sync using a standard VM server instance based on a Dropbox-like system architecture.
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M3 - Conference contribution
AN - SCOPUS:85050958428
T3 - Proceedings of the 16th USENIX Conference on File and Storage Technologies, FAST 2018
SP - 155
EP - 168
BT - Proceedings of the 16th USENIX Conference on File and Storage Technologies, FAST 2018
PB - USENIX Association
T2 - 16th USENIX Conference on File and Storage Technologies, FAST 2018
Y2 - 12 February 2018 through 15 February 2018
ER -