Competitive parallel disk prefetching and buffer management
Rakesh D. Barve, Mahesh Kallahalla, Peter Varman, Jeffrey Scott Vitter · 1997
IntroductionWe provide a competitive analysis framework for online ptefetching and buffer management algorithms in parallel I/O systems, using a read-once model of block references.This has widespread applicability to key I/O-bound applications such as external merging and concurrent playback of multiple video streams.Two realistic lookahead models, global lookahead and local lookahead, am defined.Algorithms NOM and GREED based on these two forms of lookahead are analyzed for shared buffer and distributed buffer configurations, both of which occur frequently in existing systems.An important aspect of our work is that we show how to implement both the models of lookahead in practice using the simple techniques of forecasting and flushing.'NotethatnplacementdecisionsareneccssitatedbythefactthattbeUObuffercan hold only some fixed number, say M. of pages.