Supercomputers in Grids - Cloud, Grid and High Performance Computing: Emerging Applications - page 5

Grids Do Support Supercomputing This definition is very close to the concept

of metacomputing coupling supercomputers to
increase the level of performance. The Grid was
intended to replace the local supercomputer. Soon,
however it became clear that the Grid concept
could and should be extended and Foster, Kessel-
man & Tuecke (2001) describe the Grid as

The idea of the Grid is mainly an idea of coordina-
tion and consolidation. These aspects have been
widely ignored by the supercomputing community
for a long time. A supercomputer was - and still is
today - a one of a kind system. It is only available
to a small number of users. Its mode of operation
can be compared to the exclusive usage of an
experimental facility. Typically, a supercomputer
has no free resources. The user typically has to
wait to use a supercomputer system - not the
other way round.
Access to a supercomputer is hence not seen to
be a standard service and no specific measures are
taken to provide supercomputing at a comparable
level of service as is done for other IT-services.
The Grid has, however, changed our view
of supercomputers. From stand-alone systems,
they have turned into “large nodes” of a mesh
of resources. Although they are still unique in
their potential to solve large problems the Grid
has integrated them now into an ecosystem in
which they play an important role. Being part of
such a larger IT-landscape supercomputers have
started to benefit substantially from lower level
systems technology. This is in a sense a change
of paradigm since so far supercomputers have
typically been ahead of smaller systems in terms
of complexity and level of technology. The flow
of innovation - that traditionally was directed
from supercomputers towards PCs - has at least
partially been reversed.
The current situation can be described as
follows: Supercomputers have been integrated
into an ecosystem of IT-services. The quality of
service for users has been improved. Aspects like
security, accounting and data management have
been brought in by the Grid community and the
supercomputing community has picked them up.
The notable exceptions are dedicated large scale
system in classified installations. It remains to
be seen whether these can remain in splendid
isolation without losing contact with the techno-

… flexible, secure, coordinated resource sharing
among dynamic collections of individuals, institu-
tions, and resources.

This is a much wider definition of the concept
which goes way beyond the narrow problem of
supercomputing. For the purpose of this article we
use this second definition. We keep in mind though
that the Grid started out as a concept to comple-
ment the existing supercomputing architectures.

GRIDS AND SUPERCOMPUTERS

Today the main building blocks to create a real
scientific Grid are mainly in place. High speed
wide area networks provide the necessary com-
munication performance. Security procedures
have been established which meet the limited
requirements of scientists. Data management
issues have been addressed to handle the large
amount of data created e.g. in the high energy
physics community (LHC, 2008). As of today,
virtually every industrially developed nation has
created its own national Grid infrastructure with
trans-national Grids rapidly evolving (DEISA,
2008; PRAGMA-Grid 2008).
From the point of view of supercomputing, the
question arises which role Grids can play in high
performance computing simulation. Some aspects
are briefly discussed in the following.