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.