About This Guide

This chapter includes:

What you'll find in this guide

The QNX High Availability Toolkit (HAT) Developer's Guide describes the components of the HAT and how to build robust HA-aware software running on the QNX Neutrino realtime operating system.

The following table may help you find information quickly in this guide:

If you want to: Go to:
Find the introduction Introduction
Know the main components of the HAT What's in the HAT?
Understand the benefits of a software-oriented approach to HA The QNX Approach to HA
Get an overview of the HAM and Guardian "watchdogs" Using the High Availability Manager
Find out which standard QNX library functions have HA covers Using the Client Recovery Library
Look up a convenience function (e.g. ha_recover()) Client Recovery Library Reference
Look up a HAM API function (e.g. ham_attach()) HAM API Reference
See sample code listings for handling various HA scenarios The Examples appendix
Look up a special term used in this guide Glossary

Note: For an overview of the QNX Neutrino RTOS, see the System Architecture manual in the OS documentation set.

Typographical conventions

Throughout this manual, we use certain typographical conventions to distinguish technical terms. In general, the conventions we use conform to those found in IEEE POSIX publications. The following table summarizes our conventions:

Reference Example
Code examples if( stream == NULL )
Command options -lR
Commands make
Environment variables PATH
File and pathnames /dev/null
Function names exit()
Keyboard chords Ctrl-Alt-Delete
Keyboard input something you type
Keyboard keys Enter
Program output login:
Programming constants NULL
Programming data types unsigned short
Programming literals 0xFF, "message string"
Variable names stdin
User-interface components Cancel

We use an arrow (-->) in directions for accessing menu items, like this:

You'll find the Other... menu item under Perspective-->Show View.

We use notes, cautions, and warnings to highlight important messages:


Note: Notes point out something important or useful.


Caution: Cautions tell you about commands or procedures that may have unwanted or undesirable side effects.


WARNING: Warnings tell you about commands or procedures that could be dangerous to your files, your hardware, or even yourself.

Note to Windows users

In our documentation, we use a forward slash (/) as a delimiter in all pathnames, including those pointing to Windows files.

We also generally follow POSIX/UNIX filesystem conventions.

Navigation buttons

At the top and bottom of our HTML docs, you'll see some or all of these buttons:

Use this button: To move:
Previous To the previous part of the document.
Contents "Up" in the document:
  • In a prose book, this typically takes you to About This Guide.
  • In a reference book, it takes you to the listing of items that start with a given letter. For example, if you're looking at the docs for abs(), this button takes you to the listing of the functions that start with A.
Keyword index To the keyword index.
Next To the next part of the document.

Technical support

To obtain technical support for any QNX product, visit the Support + Services area on our website (www.qnx.com). You'll find a wide range of support options, including community forums.

Copyright © 2004-2007, QNX Software Systems GmbH & Co. KG. All rights reserved.