High Performance Linux Clusters with OSCAR, Rocks, OpenMosix, and MPI [Electronic resources] نسخه متنی

6.2 What's in OSCAR

OSCAR
brings together a number of software packages for clustering. Most of
the packages listed in this section are available as standalone
packages and have been briefly described in Chapter 2. Some of the more important packages are
described in detail in later chapters as well. However, there are
several scripts unique to OSCAR. Most are briefly described in this
chapter.

It is likely that everything you really need to get started with a
high-performance cluster is included either in the OSCAR tar-ball or
as part of the base operating system OSCAR is installed under.
Nonetheless, OSCAR provides a
script, the Oscar Package Downloader (opd) that
simplifies the download and installation of additional packages that
are available from OSCAR repositories in an OSCAR-compatible format.
opd is so easy to use that for practical
purposes any package available through opd can
be considered part of OSCAR. opd can be invoked
as a standalone program or from the OSCAR installation
wizard, the GUI-based OSCAR installer. Additional packages
available using opd include things like Myrinet
drivers and support for thin OSCAR clients, as well as management
packages like Ganglia. Use of opd is described
later in this chapter.

OSCAR packages fall into three categories. Core packages must be
installed. Included packages are distributed as part of OSCAR, but
you can opt out on installing these packages. Third-party packages
are additional packages that are available for download and are
compatible with OSCAR, but aren't required. There
are six core packages at the heart of OSCAR that you must
install:

Core

This is the core OSCAR package.

C3

The Cluster, Command, and Control tool suite provides a command-line
administration interface (described in Chapter 10).

Environmental Switcher

This is based on Modules, a Perl script that allows the user to make
changes to the environment of future shells. For example, Switcher
allows a user to change between MPICH and LAM/MPI.

oda

The OSCAR database application provides a central database for OSCAR.

perl-qt

This is the Perl object-oriented interface to the Qt GUI toolkit.

SIS

The System Installation Suite is used to install the operating
systems on the clients (described in Chapter 8).

OSCAR includes a number of packages
and scripts that are used to build your cluster. The installation
wizard will give you the option of deciding which to include:

disable-services

This script disables unneeded services on the clients, such as
kudzu, slocate, and mail
services such as sendmail.

networking

This script configures the cluster server as a caching nameserver for
the clients.

ntpconfig

This script configures NTP. OSCAR uses NTP to synchronize clocks
within the cluster.

kernel_picker

This is used to change the kernel used in your SIS image before
building the cluster nodes.

loghost

This configures syslog settings, e.g., it
configures nodes to forward syslog messages to
the head node.

OSCAR provides additional system tools, either as part of the OSCAR
distribution or through opd, used to manage your
cluster:

Autoupdate

This is a Perl script used to update clients and the server (similar
to up2date or autorpm).

clumon (by opd)

Clumon is a web-based
performance-monitoring system from NCSA.

Ganglia (by opd)

Ganglia is a real-time monitoring system and execution environment
(described in Chapter 10).

MAUI

This job
scheduler is used with openPBS.

Myrnet drivers (by opd)

If you have Myrnet hardware, you need to load drivers for it.

openPBS

The portable batch system is a workload management system (described
in Chapter 11).

Pfilter

This package is used to generate sets of rules used for packet
filtering.

PVFS (by opd)

Parallel Virtual File System is a high-performance, scalable,
parallel virtual file system (described in Chapter 12).

OPIUM

This is the OSCAR password installer and user management toolset.

thin client (by opd)

This package provides support for diskless OSCAR nodes.

Torque (by opd)

The Tera-scale Open-source Resource and QUEue manager resource
manager is based on openPBS.

VMI (by opd)

The Virtual Machine Interface provides a middleware communications
layer for SAN over grids.

Of course, any high-performance cluster
would be incomplete without programming tools. The OSCAR distribution
includes four packages, while two more (as noted) are available
through opd:

HDF5

This is a hierarchical data format library for maintaining scientific
data.

LAM/MPI

This is one implementation of the message passing interface (MPI)
libraries (described in Chapter 9).

MPICH

This is another implementation of the message passing interface (MPI)
libraries (also described in Chapter 9).

MPICH-GM (by opd)

This package provided MPICH with support for low-level message
passing for Myrnet networks.

MPICH-VMI (by opd)

This version of MPICH uses VMI.

PVM

This package provides the parallel virtual machine system, another
message passing library.

If you install the four included packages, the default, they should
cover all your programming needs.

Additionally, OSCAR will install
and configure (or reconfigure) a number of services and packages
supplied as part of your Linux release.^[1]
These potentially include Apache,
DHCP, NFS,
mySQL, openSSL,
openSSH, rrdtool,
pcp, php,
python, rsync,
tftp, etc. Exactly which of these is actually
installed or configured will depend on what other software you elect
to install. In the unlikely event that you are unhappy with the way
OSCAR sets up any of these, you'll need to go back
and reconfigure them after the installation is completed.

^[1] Sometimes
OSCAR needs to make slight changes to packages. By convention, the
replacement packages that OSCAR uses have oscar as
part of their names, e.g.,

lam-oscar-7.0-2.i586.rpm .