Title: Exploring the Practical Properties of LDPC Erasure Codes in
                  Wide-Area Storage Systems

SPeaker: Jim Plank.

Abstract:

As peer-to-peer and widely distributed storage systems proliferate,
the ability to perform efficient erasure coding, instead of
replication, is crucial to performance and efficiency.  Low-Density
Parity-Check (LDPC) codes have arisen as alternatives to standard
erausre codes, such as Reed-Solomon codes, trading off vastly
improved decoding performance for inefficiencies in the amount of
data that must be acquired to perform decoding.  The scores of papers
written on LDPC codes typically analyze their collective and
asymptotic behavior.  Unfortunately, their practical application
requires the generation and analysis of individual codes for finite
systems.

This talk will detail two explorations of LDPC codes as they apply to
widely distributed storage systems.  In the first, we explore the
performance of codes, generated using asymptotic parameters, on
finite storage systems.  In the second, we explore the properties of
very small codes, focusing in particular on optimality, and the
properties of optimal codes.  In each exploration, we address
fundamental, practical, and heretofore unanswered questions about
LDPC codes, and make inroads into the answers to these questions.

Bio:

Jim Plank is an Associate Professor in the Department of Computer
Science at the University of Tennessee.  He received his BS from Yale
in 1988, and his PhD from Princeton in 1993. He has been at the
University of Tennessee since 1993. Professor Plank's main research
focus has been in fault-tolerant computing systems, focusing
specifically on checkpointing and rollback recovery, and applying
erasure coding techniques to network storage systems.  Additionally,
he has helped to co-pioneer "Logistical Networking" systems
that are deployed in the wide area, but are built upon classic
End-to-End principals.  Professor Plank is an Associate Editor of
IEEE TPDS, has chaired conferences in network storage and
network applications, and has left a legacy of publicly available
software that includes: Jgraph, Ickp, Libckpt, IBP, LoRS and GFLib.

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