Availability Guide for Change Management

Reducing the Time Required for Planned Outages
Availability Guide for Change Management–125506
6-4
Can the Change Be Performed Online?
Can the Change Be Performed Online?
You can perform many changes to your NonStop system online. Online change is any
change that can be performed while your NonStop system is still operational. Sections
4, 5, and 6 of this manual are designed to help you determine whether the changes you
want to make can be performed online. Table 6-3 describes the contents of these
sections.
In some situations, online changes can affect application availability. These types of
online changes require the application to become temporarily unavailable and can result
in planned outages. The information in Sections 3, 4, and 5 identifies the types of online
changes that can affect application availability.
Reducing System and Application Startup and
Shutdown Time
An important component of many outages is the time required to start and stop your
system and application. The following general techniques can help you reduce the time
required to start up and shut down your system and applications:
•
Writing efficient startup and shutdown command files
•
Using parallel processing to distribute startup and shutdown processes across
multiple processors
Writing Efficient Startup and Shutdown Command Files
The best way to start and stop your system and applications is by using command files.
A command file is a file that contains a series of commands. When the file is executed,
the commands within the file are automatically executed. Command files are supported
by the Tandem Advanced Command Language (TACL) and many Tandem subsystems.
Table 6-3. Where to Find Information About Online Change
Section
Number Section Title What it contains
3 “Making System Software
and Hardware Changes
Online”
Identifies the hardware changes you can perform
online.
4 “Making Application
Subsystem Changes Online”
Identifies the changes you can perform online to
the three key products that make up the Tandem
application environment—NonStop TS/MP,
NonStop SQL/MP, and NonStop TM/MP.
5 “Making Communications
Subsystem Changes Online”
Identifies common communications subsystem
changes and the tools you can use to perform those
changes online.