Availability Guide for Change Management

Making Application Subsystem Changes Online

Availability Guide for Change Management–125506

4-6

NonStop TS/MP Changes You Can Perform Online

Making changes to NonStop TS/MP does not require the NonStop system to be shut

down, and most changes can be made without affecting the availability of the

transaction-processing application. The following subsections describe common

transaction-processing environment changes.

Adding Hardware

You can attach more terminals, disk drives, peripheral devices, and processors to your

NonStop system without having to recode your transaction-processing application.

After the new hardware is physically installed, you identify the hardware to PATHMON

using PATHCOM commands (see “Adding and Deleting Objects Controlled by

PATHMON”).

Adding and Deleting Objects Controlled by PATHMON

As your transaction-processing system grows to meet changing business requirements,

you may need to add additional objects to handle new types of transactions or

processing functions, or delete existing objects. For example, you might want to add a

SERVER (an object controlled by PATHMON that defines a server class) to distribute

the transaction workload.

To add an object to your PATHMON environment, you use PATHCOM commands to

define the attributes of the object and then identify the new object to the transaction-

processing system. Deleting an object may involve stopping the object (this depends on

the type of object you want to delete), and then removing the object definition from the

PATHMON configuration file. You can perform these changes while your application is

still active and processing transactions. Table 4-1 lists the object types that must be

stopped before they can be deleted.

Altering Objects Controlled by PATHMON

Business growth may also require you to change the attributes of existing PATHMON

objects. For example, you can reconfigure requesters and servers to run in different

processors within the same system or on different nodes of an Expand network.

Certain objects controlled by PATHMON must be stopped before their attributes can be

altered. Table 4-1 summarizes the types of changes you can make to PATHMON objects

and whether they require that the object be stopped. Stopping an object controlled by

PATHMON may affect application availability.

Note. See Section 3, “Making System Software and Hardware Changes Online,” for

information about adding hardware online.