Speaker
M. Jones
(Manchester University)
Description
The BaBar experiment has accumulated many terabytes of data on
particle physics reactions, accessed by a community of hundreds of
users.
Typical analysis tasks are C++ programs, individually written by the
user, using shared templates and libraries. The resources have
outgrown a single platform and a distributed computing model is
needed. The grid provides the natural toolset. However, in contrast
to the LHC experiments, BaBar has an existing user community with an
existing non-Grid usage pattern, and providing users with an
acceptable evolution presents a challenge.
The 'Alibaba' system, developed as part of the UK GridPP project,
provides the user with a familiar command line environment. It draws
on the existing global file systems employed and understood by the
current user base. The main difference is that they submit jobs with
a 'gsub' command that looks and feels like the familiar'qsub'.
However it enables them to submit jobs to computer systems at
different institutions, with minimal requirements on the remote
sites. Web based job monitoring is also provided. The problems and
features (the input and output sandboxes, authentication, data
location) and their solutions are described.
