Using and Administering

This section contains some of the terms that are commonly used in the LoadLeveler books and in this book in particular.

IBM is grateful to the American National Standards Institute (ANSI) for permission to reprint its definitions from the American National Standard Vocabulary for Information Processing (Copyright 1970 by American National Standards Institute, Incorporated), which was prepared by Subcommittee X3K5 on Terminology and Glossary of the American National Standards Committee X3. ANSI definitions are preceded by an asterisk (*).

Other definitions in this glossary are taken from IBM Vocabulary for Data Processing, Telecommunications, and Office Systems (GC20-1699), IBM DATABASE 2 Application Programming Guide for TSO Users (SC26-4081), and Internetworking With TCP/IP, Principles, Protocols, and Architecture, by Douglas Comer, Copyright 1988 by Prentice Hall, Incorporated

A

AFS

Andrew File System.

AIX

Abbreviation for Advanced Interactive Executive, IBM's licensed version of the UNIX operating system. AIX is particularly suited to support technical computing applications, including high function graphics and floating point computations.

Authentication

The process of validating the identity of a user or server.

Authorization

The process of obtaining permission to perform specific actions.

B

Berkeley Load Average

The average number of processes on the operating system's ready to run queue.

C

C

A general purpose programming language. It was formalized by ANSI standards committee for the C language (X3J11) in 1984 and by Uniforum in 1983.

client

*(1) A function that requests services from a server, and makes them available to the user. *(2) An address space in MVS that is using TCP/IP services. *(3) A term used in an environment to identify a machine that uses the resources of the network.

cluster

(1) A group of processors interconnected through a high speed network that can be used for high performance computing. (2) A group of jobs submitted from the same job command file. (3)A set of machines with something in common between them. This commonality could be that they are all backed up by one machine or they are all in the LoadLeveler administration file.

D

daemon

A process, not associated with a particular user, that performs system-wide functions such as administration and control of networks, execution of time-dependent activities, line printer spooling, and so on.

datagram

A protocal known as the User Datagram Protocol (UDP). It is an internet standard protocol that allows an application program on one machine to send a datagram to an application program on another machine. UDP uses the Internet Protocol to deliver datagrams. Conceptually, the important difference between UDP and IP is that UDP messages include a protocol port number, allowing the sender to distinguish among multiple destinations (application programs) on the remote machines. In practice, UDP also includes a checksum over the data being sent.

DCE

Distributed Computing Environment.

default

An alternative value, attribute, or option that is assumed when none has been specified.

DFS

Distributed File System. A subset of the IBM Distributed Computing Environment.

H

host

A computer connected to a network, and providing an access method to that network. A host provides end-user services.

M

menu

A display of a list of available functions for selection by the user.

Motif

The UNIX industry's standard user interface, originally developed by the Open Systems Foundation. Motif is based on the X-Window system and is a Presentation Manager look-alike. Motif is available for all IBM AIX workstations.

N

network

An interconnected group of nodes, lines, and terminals. A network provides the ability to transmit data to and receive data from other systems and users.

NFS

Network File System.

node

In a network, the point where one or more functional units interconnect transmission lines. A computer location defined in a network.

NQS

Network Queueing System.

P

parameter

*(1) A variable that is given a constant value for a specified application and that may denote the application. *(2) An item in a menu for which the operator specifies a value or for which the system provides a value when the menu is interpreted. *(3) A name in a procedure that is used to refer to an argument that is passed to the procedure. *(4) A particular piece of information that a system or application program needs to process a request.

process

*(1) A unique, finite course of events defined by its purpose or by its effect, achieved under defined conditions. *(2) Any operation or combination of operations on data. *(3) A function being performed or waiting to be performed. *(4) A program in operation. For example, a daemon is a system process that is always running on the system.

S

SDR

Abbreviation for System Data Repository. A repository of system information describing SP hardware and operating characteristics.

server

(1) A function that provides services for users. A machine may run client and server processes at the same time. (2) A machine that provides resources to the network. It provides a network service, such as disk storage and file transfer, or a program that uses such a service.

shell

The shell is the primary user interface for the UNIX operating system. It serves as command language interpreter, programming language, and allows foreground and background processing. There are three different implementations of the shell concept: Bourne, C and Korn.

stream

An internet standard transport level protocol that provides the reliable, full duplex, stream service on which many application protocols depend. TCP allows a process on one machine to send a stream of data to a process on another. It is connection-oriented in the sense that before transmitting data, participants must establish a connection. Software implementing TCP usually resides in the operating system and uses the IP protocol to transmit information across the Internet. It is possible to terminate (shut down) one direction of flow across a TCP connection, leaving a one-way (simplex) connection. The Internet protocol suite is often referred to as TCP/IP because TCP is one of the two most fundamental protocols.

System Administrator

The user who is responsible for setting up, modifying, and maintaining LoadLeveler.

U

user

Anyone who is using LoadLeveler.

W

working directory

All files without a fully qualified path name are relative to this directory.

workstation

*(1) A configuration of input/output equipment at which an operator works. *(2) A terminal or microcomputer, usually one that is connected to a mainframe or to a network, at which a user can perform applications.