The Role of Linux in Grid Computing

Today, applications are developed to be geared toward a specific platform or
hosting environment, for example Linux, Windows 2000, various UNIX flavors,
mainframes, J2EE, Microsoft .NET and so on. Such computing tends to operate
within a monolithic framework in which applications contend for resources as and
when they're made available for that single platform. For a platform with
limited resources, the resource availability starts decreasing as the demand
for service grows. At such a time, if resources from other systems could be
used or, in turn, the requirements could be serviced by resources from
other systems, the strain on the native system would reduce considerably and the quality of
service being offered would improve.

It is this objective that grid computing wants to meet. The objective of
grid-based computing is to virtualize, manage and allocate distributed
physical resources (processing power, memory, storage, networking) to
applications and users on an as-needed (on-demand) basis--regardless of the
resources' location. Grid networks transcend physical components,
organizational units, enterprise infrastructure and geographic boundaries.
Naturally, software plays a vital role in determining the success of grid
computing. In this article, we focus on the role of Linux in grid
computing.

Four arguments can be made for Linux becoming the basis of grid computing:

1. Open Grid Services
Architecture (OGSA) is a service architecture built on the
open-source paradigm of community participation and sharing code.
According to the father of the grid, Ian Foster, a chief scientist at Argonne
National Laboratory, the long-term success of grid computing depends on
four issues: open standards, open software, open infrastructure and
commercializing grid services to speed enterprise adoption. The development
of Linux has progressed along similar lines.

The Globus Toolkit, which formed the basis of OGSA, is a community-based,
open-architecture, open-source set of services and software libraries. Globus addresses issues of security,
information discovery, resource management, data management, communication,
fault detection and portability. Thus, it mirrors the community processes
used for the development and evolution of the Linux kernel. Any grid network
must accommodate a heterogeneous mix of existing resources. However, future
generations of grid networks likely will center around operating system and
development environments that support an open and collaborative community
process whose infrastructure evolves through an open-source process.
Because Linux has evolved from the same open-source process, there is a high degree
of affinity between Linux and grid-computing projects. Open standards and
protocols lead to the building of services, and services are at the heart of
the grid.

2. The grid concept is based on the management and allocation of distributed
resources rather than on a vertically integrated, monolithic resource tightly
coupled to the underlying operating-system architecture of the platform.

The adoption of grid computing from single platform architectures will not
happen all of a sudden. A few computational units will have to be deployed in
small, inexpensive increments. The performance of these units will be
measured and compared to the expected results. If the gain is significant,
only then would there be a next round of deployments. This is in contrast to the major
investments needed for large-scale monolithic systems, which typically
are obsolete within four or five years and thus are a drain on capital and
operating budgets.

Linux has gained a reputation for being a highly efficient operating system
in simpler application environments running on smaller hardware
configurations, the type that will be enabled by the grid architecture.
In such experimentation-based systems, the free nature of Linux will
play a crucial important role due to lower investments.

3. Computing grids are virtual, extensible and horizontally scalable and use
open network protocols. Many of the early instances of grid networks were developed in the scientific
and technical computing environments of universities, technical laboratories,
health and bio-informatics consortia. Most of them have relied on native
operating system processes for the hosting environment, typically UNIX and
Linux. Their experience suggests that Linux is the best platform
available for grid computing. There has hardly been any evidence of grid
computing projects being deployed on other operating systems, such as
Windows 98 or Windows XP.

For example, the TeraGrid is designed to help the National Science Foundation address
complex scientific research, including molecular modeling for disease
detection, cures and drug discovery, automobile crash simulation and
investigations of alternative energy sources. TeraGrid will use more than
3,000 Intel processors running Linux. The Grid Forum, a research consortium,
is aiming its research at applications in the oil industry, physical disaster
prediction and simulation, biological and ocean modeling, industrial
simulations, agriculture applications, health service applications and
e-utilities. Many of these applications currently run on UNIX or Linux.

4. Vendor-specific initiatives are promoting Linux.
Although IBM's grid architectural block diagrams show the OGSA framework
supporting operating system heterogeneity, they also clearly point to the
centrality of Linux in IBM's grid strategy. Sun Microsystems has written an
edition of its Grid Engine 5.3 software for the version of Linux
available through SuSE Linux AG. Other vendors are
investing in grid computing as well. Hewlett-Packard has incorporated software specs
for massive grids into the Utility Data Center, a computing power-on-demand
product that supports Linux. An Oracle spokesman recently said Linux is
"the smart option for grid computing". In addition, Oracle recently announced
that the Oracle 10g package is grid-enabled and runs smoothly on Linux.

On the whole, Linux is the buzzword as far as the platform for grid computing
is concerned. But, arguments against pervasive adoption of Linux exist.
A few them are listed below:

1. Grid computing is based on the principle of heterogeneity, where virtual
organizations are formed with no discrimination between resources and
systems, as long as the standard toolkit services are implemented.

The OGSA model does not specify an operating system. On the contrary, it has
been developed so as to invite all computing architectures into
the grid-computing family. Given grid computing's emphasis on resource
virtualization and usage and the heterogeneous nature of most enterprises' IT
infrastructures, enterprises are under no pressure to change their hardware
and software to participate in grids or establish internal grids.

2. The grid philosophy does not specify
implementations: its fundamental
principle is to adapt to the operating system environment of specific hosts
and exploit their native capabilities.

The grid architecture does not suggest or inhibit ways or solutions for
implementation of grid architecture. Similarly, it does not specify anything
about the platform to be used.

3. Grid computing addresses only a small part of the IT infrastructure.
Grid computing is exactly what it implies--a mesh of distributed resources whose
members share each other's resources through a specifically enforced set of
protocols. The heterogeneity that OGSA attempts to address is in itself
recognition that IT infrastructures will consist of a mix of computing
architectures.The role Linux will play in such heterogeneous environments
will depend largely on its performance, reliability and economics when
running on such hosts.

Both grid computing and Linux are too immature for us to forecast that Linux
will dominate in commercial grid applications. Only the future will tell
whether the realm of grid computing is ruled by Linux. One thing is
for sure, however; Linux definitely will form a large chunk in the Grid Computing
Platform market.
Resources
www.techrepublic.com

www-106.ibm.com/developerworks/grid

www.itweb.co.za

Aseem has been working at Cygnus Microsystems Pvt Ltd, in India,
for the past 15 months. He has special interests in grid computing and supercomputing.