Manage application monitor properties for a cluster

Use this task to view and edit application monitor properties. The properties of the application monitors are displayed based on the application monitor type.

To edit the properties of process monitor, see Edit process monitor properties

To edit the properties of custom monitor, see Edit custom monitor properties

Edit process monitor properties

Application monitor type
Specify one of the following application monitor types:
Process
The termination of one or more processes of an application is detected by resource monitoring and control (RMC).
Custom
The health of an application is checked by a custom monitor method at user-defined polling intervals.
Processes to monitor
Specify the unique names of one or more processes that are being monitored. The output of the /usr/bin/ps -el command provides the process name. This field can be set only for a Process monitor.
Process owner
Specify the user name of the owner of the processes. This field can be set only for a Process monitor.
Instance count
Specify the number of instances of a process to monitor. If more than one process is specified in the Process to monitor field, the instance count is 1. This field can be set only for a Process monitor.
Stabilization interval (seconds)
Specify the time interval, in seconds, for the PowerHA® SystemMirror to wait before performing the action. The stabilization period is used in different ways based on the type of monitor mode that you select.
  • When the Monitor mode field is set to Long-Running Monitoring, the stabilization interval is the period during which PowerHA SystemMirror waits for the application to stabilize before it starts monitoring for the successful running of the application.

    For instance, with a database application, you might want to delay monitoring until after the start script and initial database search have been completed. Experiment with this value to balance performance with reliability.

  • When the Monitor mode field is set to Startup Monitoring, the stabilization interval is the period within which PowerHA SystemMirror monitors that the application has successfully started.

    When the time expires, PowerHA SystemMirror stops monitoring the application startup and continues event processing. If the application fails to start within the stabilization interval, the resource group acquisition fails for the node and PowerHA SystemMirror begins resource recovery actions to acquire the group on another node.

    The number of seconds you specify must be equal to the time it takes for the application to start. This depends on the application you are using.

  • When the Monitor mode field is set to Both, the application monitor waits for the specified length of time for the application to start successfully. It uses the same interval to wait before the application monitor begins to check that the application is successfully running on the node.
Restart count
Specify the number of times to restart the application controller.
Restart interval (seconds)
Specify the number of seconds (in addition to the Stabilization interval field) that the application must remain stable before resetting the Restart count.
Monitor mode
Select one of the following modes for the application monitor:
  • When you select Startup Monitoring, the application monitor checks that the application controller successfully starts within the specified stabilization interval.

    Select this mode if you are configuring an application monitor for an application that is included as a parent resource group in a parent-child dependency.

  • When you select Long-Running Monitoring, the application monitor periodically checks that the application controller is running after the specified stabilization interval ends. This is the default mode.
  • When you select Both, the application monitor checks that the application controller successfully starts within the stabilization interval. The application monitor periodically monitors that the application controller is running after the specified stabilization interval ends.
Action on application failure
Select the action that the application monitor must take after all restart attempts are exceeded:
  • When you select Notify, the application monitor runs the specified notify script and takes no further action.
  • When you select Failover, the application monitor moves the resource group that contains the monitored application to another node in the cluster.
Notify script
Specify the full path and file name of the script that the application monitor must run to perform notification when the application fails.
The application monitor runs this script each time the application monitor restarts an application if the application fails completely or if the application falls over to the next node in the cluster. Configuring and specifying a script to perform notification is preferred. You cannot specify arguments for this script.
Note: Notify scripts are run only for failure of long-running application monitors, regardless of the Action on application failure option that you selected.
Cleanup script
Specify the full path and file name of the script that the application monitor must run to stop the application. The default cleanup script is the stop script that is defined for the application controller when the application controller is configured. If the application monitor belongs to more than one application controller, specify a cleanup script specific to this application monitor. In this case, do not rely on the default stop script.

If the Monitor mode field is set to Startup monitoring, you do not have to specify a cleanup script. PowerHA SystemMirror will not use it. You cannot specify arguments for this script.

Restart script
Specify the full path and file name of the script that the application monitor must run to start the application. The default restart script is the start script that is defined for the application controller when the controller is configured. If the monitor belongs to more than one application controller, there is no default stop script.

If the Monitor mode field is set to Startup monitoring, you need not specify a restart script because PowerHA SystemMirror will not use it. You cannot specify arguments for this script.

Edit custom monitor properties

Application monitor type
Specify one of the following application monitor types:
Process
The termination of one or more processes of an application is detected by resource monitoring and control (RMC).
Custom
The health of an application is checked by a custom monitor method at user-defined polling intervals.
Monitor script
Specify the full path and file name of a method to check the application status. This field can be set only for a Custom monitor. You cannot specify arguments for this script.
Monitor interval (seconds)
Specify the polling interval in seconds for checking the health of the application. If the application monitor does not respond within this interval, the application is considered to be hung. This field can be set only for a Custom monitor.
Hung monitor signal
Specify the signal, in numbers, that the system must send to stop the Monitor Script if it does not return within the time specified for the Monitor Interval. This field can be set only for a Custom monitor and the default value is 9 (SIGKILL).
Stabilization interval (seconds)
Specify the time interval, in seconds, for the PowerHA SystemMirror to wait before performing the action. The stabilization period is used in different ways based on the type of monitor mode that you select.
  • When the Monitor mode field is set to Long-Running Monitoring, the stabilization interval is the period during which PowerHA SystemMirror waits for the application to stabilize before it starts monitoring for the successful running of the application.

    For instance, with a database application, you might want to delay monitoring until after the start script and initial database search have been completed. Experiment with this value to balance performance with reliability.

  • When the Monitor mode field is set to Startup Monitoring, the stabilization interval is the period within which PowerHA SystemMirror monitors that the application has successfully started.

    When the time expires, PowerHA SystemMirror stops monitoring the application startup and continues event processing. If the application fails to start within the stabilization interval, the resource group acquisition fails for the node and PowerHA SystemMirror begins resource recovery actions to acquire the group on another node.

    The number of seconds you specify must be equal to the time it takes for the application to start. This depends on the application you are using.

  • When the Monitor mode field is set to Both, the application monitor waits for the specified length of time for the application to start successfully. It uses the same interval to wait before the application monitor begins to check that the application is successfully running on the node.
Restart count
Specify the number of times to restart the application controller.
Restart interval (seconds)
Specify the number of seconds (in addition to the Stabilization interval field) that the application must remain stable before resetting the Restart count.
Monitor mode
Select one of the following modes for the application monitor:
  • When you select Startup Monitoring, the application monitor checks that the application controller successfully starts within the specified stabilization interval.

    Select this mode if you are configuring an application monitor for an application that is included as a parent resource group in a parent-child dependency.

  • When you select Long-Running Monitoring, the application monitor periodically checks that the application controller is running after the specified stabilization interval ends. This is the default mode.
  • When you select Both, the application monitor checks that the application controller successfully starts within the stabilization interval. The application monitor periodically monitors that the application controller is running after the specified stabilization interval ends.
Action on application failure
Select the action that the application monitor must take after all restart attempts are exceeded:
  • When you select Notify, the application monitor runs the specified notify script and takes no further action.
  • When you select Failover, the application monitor moves the resource group that contains the monitored application to another node in the cluster.
Notify script
Specify the full path and file name of the script that the application monitor must run to perform notification when the application fails.
The application monitor runs this script each time the application monitor restarts an application if the application fails completely or if the application falls over to the next node in the cluster. Configuring and specifying a script to perform notification is preferred. You cannot specify arguments for this script.
Note: Notify scripts are run only for failure of long-running application monitors, regardless of the Action on application failure option that you selected.
Cleanup script
Specify the full path and file name of the script that the application monitor must run to stop the application. The default cleanup script is the stop script that is defined for the application controller when the application controller is configured. If the application monitor belongs to more than one application controller, specify a cleanup script specific to this application monitor. In this case, do not rely on the default stop script.

If the Monitor mode field is set to Startup monitoring, you do not have to specify a cleanup script. PowerHA SystemMirror will not use it. You cannot specify arguments for this script.

Restart script
Specify the full path and file name of the script that the application monitor must run to start the application. The default restart script is the start script that is defined for the application controller when the controller is configured. If the monitor belongs to more than one application controller, there is no default stop script.

If the Monitor mode field is set to Startup monitoring, you need not specify a restart script because PowerHA SystemMirror will not use it. You cannot specify arguments for this script.