1 Optimizing Remote File Access for Parallel and Distributed Network Applications Jon B. Weissman * , Mahesh Marina + , and Michael Gingras + Department of Computer Science and Engineering University of Minnesota, Twin Cities * Division of Computer Science University of Texas at San Antonio + (jon@cs.umn.edu) Abstract This paper presents a paradigm for remote file access called Smart File Objects (SFOs). The SFO is a realization of the ELFS (Extensible File Systems) concept of files as typed objects, but applied to wide-area networks [9]. The SFO is an object-oriented application-specific file access paradigm designed to address the bottleneck imposed by high latency, low bandwidth, unpredict- able, and unreliable networks such as the current Internet. Newly emerging network applications such as multimedia, metacomputing, and collaboratories, will have different sensitivities to these network “features”. These applications will require a more flexible file access mechanism than is provided by conventional distributed file systems. The SFO uses application and network infor- mation to adaptively prefetch and cache needed data in parallel with the execution of the applica- tion to mitigate the impact of the network. Preliminary results indicate that the SFO can provide substantial performance gains for network applications. 1 1.0 Introduction Network applications often require access to remote data sources. Unfortunately, the per- formance “features” of current wide-area network: high latency, low bandwidth, unpredictable latency and bandwidth, and poor reliability can be an obstacle for network applications. Collec- 1. This work was partially funded by grants NSF ACIR-9996418 and CDA-9633299, AFOSR-F49620-96-1-0472, and ARP 010115-226.