3.6.1 Monitoring UAPs

To monitor server programs in the monitor mode, the user normally creates a server monitoring command. By using the monitor-mode program management function, HA Monitor can monitor UAPs. You do not need to include the UAP monitoring process in the server monitoring command. If you issue APIs for UAP monitoring from UAPs, HA Monitor can monitor the UAPs and detect server failures caused by the UAPs.

The following figure shows the flow of UAP monitoring when the program management function is used.

Figure 3‒42: Flow of UAP monitoring when the program management function is used

To use the program management function to monitor UAPs, the user must include APIs in the UAPs. Therefore, UAPs can be monitored only if the UAPs can be modified to include APIs. For details about including APIs in UAPs and the conditions under which APIs can be included in UAPs, see 6.16.1 Including APIs in UAPs.

Organization of this subsection

(1) How to monitor UAPs
(2) Required environment settings

(1) How to monitor UAPs

HA Monitor uses the two methods described below to monitor UAPs and detect UAP failures. For details about these methods, see 4.7.1 UAP monitoring control.

Monitoring UAP processes

HA Monitor uses this method to determine the existence of a UAP process.
Monitoring UAP operation reports

HA Monitor uses this method to monitor the operation reports sent from UAPs.

If HA Monitor detects a UAP failure, it restarts the UAP and server. For details about the HA Monitor processing that occurs after detection of a UAP failure, see (3) HA Monitor processing after detection of a UAP failure. For details about the processing during UAP restart, see 4.7.2 Program restart control.

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(2) Required environment settings

To monitor UAPs, you must specify the following environment settings:

Environment settings that are needed to use the program management function:

To use the program management function

Specify use in the program operand in the server environment definition.
Maximum number of programs

Specify in the pgmmax operand in the HA Monitor environment settings the maximum number of programs that can run concurrently on a single host and that will be using the program management function. Because the default value is 0, make sure that you specify a pgmmax operand value.
Program management function settings

Specify the monitor-mode program environment definition. For details about the monitor-mode program environment definition, see 8.5.1 Monitor-mode program environment definition (programs).

Creating a program restart command:

If you want to restart automatically an individual UAP, rather than an individual server, in the event of a UAP failure, you must create a program restart command. You specify your program restart command in the restartcommand operand in the monitor-mode program environment definition. For details about creating program restart commands, see 6.15 Creating a program restart command (when the program management function is used).

Specifying UAP environment variables:

Specify the environment variables required for executing UAPs. For details about specifying UAP environment variables, see 6.16.2 Specifying UAP environment variables.

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