Data Distribution Alternatives - Evolution of a PDS Jukebox Architecture

Gary Walker
Jet Propulsion Laboratory
4800 Oak Grove Dr.
Pasadena, CA 91109

(818)-306-6011
gwalker@jplpds.jpl.nasa.gov

The Planetary Data System (PDS) has evaluated many data distribution
alternatives over the past several years. Although CD-ROM distribution
has proven to be an affordable mechanism for distribution of frequently
accessed data to a large user community, the cost-effectiveness of CD-ROM
production and distribution can be questioned for certain data sets.

One option for reducing CD-ROM distribution costs that is being explored
by the PDS is the use of CD-ROM jukeboxes. Jukeboxes are cost effective
for providing planetary science users access to certain "medium demand"
or "low demand" datasets. In addition, educators and other non-NASA
scientists can easily be supported with jukeboxes.

PDS is exploring various alternative CD-ROM jukebox architectures as
well. This paper will present an overview of the architectures being
explored as well as the lessons learned to date. In some cases, catalog
interfaces have been integrated with jukeboxes, restrict access to
certain files or directories or certain users. Other jukeboxes are set up
as file systems allowing users direct access to files. Software has been
implemented to help with caching, provide redundancy, and ordering.