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DAILY NEWS AND INFORMATION
FOR THE GLOBAL GRID COMMUNITY /
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Special Features:
NRC PIONEERING GRID COMPUTING IN
CANADA
By Gabriel Mateescu, National Research Council Canada
The paradigm of high performance technical computing is shifting toward
sharing of resources (such as computers, storage, instruments and software
applications) across multiple departments and organizations. Controlled
resource sharing allows budget savings and enables broader access to expensive
hardware and software. This new paradigm is called Grid computing.
The vision of the Grid proponents is that the impact of Grid technologies
on
general resource sharing will be similar to the impact of the Worldwide Web on
document sharing, and that tapping into Grid resources will ultimately be as
easy as it is today to tap into the electricity Grid. In the technical
literature, different instantiations of Grid computing are referred to as
"utility computing," "on-demand computing," "adaptive computing" or "seamless
computing."
The Grid delivers services such as scientific software simulations
(computational Grids), data collection, management and mining (data Grids), or
access to scientific instruments. A Grid should provide its users with some
level of assurance about the time it takes to respond to a request for
service. Quality of service is achieved by defining and implementing resource
access policies and by assuring resource availability and reliability.
Web services, utility computing, .NET, CPU harvesting and distributed
computing are just a few of the technologies that fall under the Grid
computing umbrella. Gt04 -- a premiere enterprise Grid computing conference
targeting industrial and commercial users -- will gather experts, and outline
strategies and road maps for Grid deployment. For more information, visit
www.gt04.com.
Grid computing is here!
The Globus Alliance (Web site: http://www.globus.org ) has defined
standards,
designed and implemented a software infrastructure for the Grid, called the
Globus Toolkit. Globus Toolkit has emerged as the de-facto standard software
for building Grids.
The Research Computing Support Group (RCSG) at the National Research
Council
Canada (NRC) has designed and implemented a distributed software system,
called SpectroGrid, which provides remote access to spectroscopy instruments
located at the NMR facility and at other sites. The NMR instruments are
controlled by third-party acquisition and visualization software, henceforth
called NMR software, which runs on computers belonging to the authorization
domains associated with the instruments.
SpectroGrid has been designed to meet the requirements of secure and
seamless
access and to allow controlled usage of the instruments along with instrument
booking for experiments. The system is composed of four main components: (i) a
Java GUI client for remote access to the NMR software, file transfer and for
credential management; (ii) a set of Web services that provide instrument and
user management, as well as instrument booking; (iii) a database that contains
information about instruments, users, managers, as well as access and usage
policies; and (iv) a Web interface for accessing the management and instrument
booking services.
We have blended three main Grid technologies in the design of the
system:
- Web Services that perform system management and instrument booking
tasks
- Grid Security Infrastructure (GSI) (a component of the Globus Toolkit)
which provides single sign-on authentication
- the GSI-enabled version of Secure Shell (SSH), for remote execution of
the
NMR software.
The Web services provide a dual functionality. On the one hand, they allow
managers to define projects, associate users and instruments with projects,
and define access policies such as instrument-project allocations, user roles,
per-user and per-project reservation quotas. On the other hand, it provides
users with a tool for scheduling access to the NMR resources. Access to the
instruments is based on creating reservations, where a reservation defines a
time interval during which a user has control over an instrument and runs the
related NMR software. Web services provide users with the reservation
functionality subject to the policies defined by the managers.
GSI uses X509 certificates and the public key infrastructure (PKI)
technologies to authenticate and authorize users. A user's identity and
credentials are defined by a private key and an associated X509 certificate
signed by a certificate authority. GSI uses a technique called proxy
credentials to provide users with portable credentials: a user only needs to
have her or his credentials stored in a single, secure location, and needs to
authenticate only once but can access multiple resources, using the proxy
created during authentication.
GSI-enabled SSH is the version of SSH that supports GSI authentication.
GSI-enabled SSH starts is used to start the remote NMR software, and it makes
the Graphical User Interface (GUI) of the NMR software visible to the user
(through the SSH X11 forwarding option), so that the user can then control the
experiment via the GUI.
For up-to-date information about the Grid-related work carried out at NRC,
please visit the Web site www.Grid.nrc-cnrc.gc.ca.
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