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09/14/2006, 9:30 AM - 10:15 AM
Speaker:
Junwei Cao, MIT.
The LIGO (Laser Interferometer Gravitational-wave Observatory) project
aims to make the first direct detection of gravitational waves as
predicted by Einstein's General Theory of Relativity. The project is a
joint enterprise of the California Institute of Technology and
Massachusetts Institute of Technology funded by the U.S. National Science
Foundation (NSF). LIGO Laboratory consists of facilities at both
universities in addition to two observatory sites in the states of
Washington and Louisiana.
The LIGO Scientific Collaboration (LSC) consists of nearly 400 scientists
from about 40 institutions. It is leading the international effort on
gravitational wave research and is responsible for the analysis of data
which the LIGO instruments collect. The LSC Data Grid (LDG) is a
production-quality grid computing infrastructure to support LIGO data
analysis and monitoring with thousands of CPUs and terabytes of data
storage capabilities distributed over ten sites in the USA and Europe.
This talk provides a brief introduction to the LDG client/server
environment, the LDG middleware to create a coherent and uniform LIGO data
analysis environment for LSC members. The environment is built on top of
the Virtual Data Toolkit (VDT) that provides general purpose grid tools
(e.g. Globus and Condor). In particular, the Globus Resource Location
Service (RLS) package and PyGlobus package are included to build the RLS
Python client previously developed by LSC in the GriPhyN project. LSC
specific utilities for applying for, retrieving and renewing DOEGrids
certificates are maintained in the LDG client/server environment. The LSC
CA and corresponding utilities are under development that will be also
incorporated in the environment in future.
The LDG client/server environment is written in Pacman 3 that provides a
convenient way to define, install, configure and setup complicate software
packages. LSC members, mostly gravitational wave physicists, can have the
LDG client installed by one command line with default configurations. LSC
systems administrators are able to have a LSC cluster grid enabled by
following a few number of explicit steps. Current LDG client supports
Fedora Core 4, Solaris and Darwin. The LDG server is only tested on Fedora
Core 4. Ongoing work includes testing and supports of x86_64 machines.
Two LSC applications are also described in this talk, which are built on
top of the LDG client/server environment. The LIGO Data Monitoring (LDM)
environment is developed to enable offline LIGO data analysis applications
implemented using the LIGO Data Monitoring Toolkit (DMT). The LDGreport is
a small utility that queries each LDG clusters for usage statistics,
coupled with LSC user information, to generate annual usage report of LDG
resources automatically. These applications interface users with a LIGO
friendly language and hide technical details of grid computing from users.
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