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Paper - 1999 USENIX Annual Technical Conference, June 6-11, 1999, Monterey, California, USA    [Technical Program]

Pp. 43–56 of the Proceedings
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Operation-based Update Propagation
in a Mobile File System 1

Yui-Wah Lee                     Kwong-Sak Leung
The Chinese University of Hong Kong

Mahadev Satyanarayanan
Carnegie Mellon University


In this paper we describe a technique called operation-based update propagation for efficiently transmitting updates to large files that have been modified on a weakly connected client of a distributed file system. In this technique, modifications are captured above the file-system layer at the client, shipped to a surrogate client that is strongly connected to a server, re-executed at the surrogate, and the resulting files transmitted from the surrogate to the server. If re-execution fails to produce a file identical to the original, the system falls back to shipping the file from the client over the slow network. We have implemented a prototype of this mechanism in the Coda File System on Linux, and demonstrated performance improvements ranging from 40 percents to nearly three orders of magnitude in reduced network traffic and elapsed time. We also found a novel use of forward error correction in this context.


... System1
This research was partially supported by the Defense Advanced Research Projects Agency (DARPA), Air Force Materiel Command, USAF under agreement number F19628-96-C-0061, the Intel Corporation, and the Novell Corporation. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of DARPA, Intel, Novell, or the U.S. Government.

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Copyright 1999 by Y.W. Lee, K.S. Leung, and M. Satyanarayanan

This paper was originally published in the Proceedings of the 1999 USENIX Annual Technical Conference, June 6-11, 1999, Monterey, California, USA
Last changed: 1 Mar 2002 ml
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