Lee, Yui-WahYui-WahLeeProf. LEUNG Kwong SakSatyanarayanan, MahadevMahadevSatyanarayanan2023-03-302023-03-301999Proceedings of the 1999 USENIX Annual Technical Conference, 1999, 1999 USENIX Annual Technical Conference1880446332978-188044633-1http://hdl.handle.net/20.500.11861/7671In 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. © 1999 by The USENIX Association All Rights Reserved.enConference Proceedings