Use this page to create and configure one or more monitors
for application controllers to use to monitor specific applications
and processes for applications in the resource group.
You can define a monitor to detect the unexpected termination of
a process or to periodically poll the termination of an application
and take automatic action upon detection of a problem. Additionally,
you can specify scripts to use for notification, cleanup, and restarting
applications in the resource group upon detection of an unexpected
termination of a process or other application failures. You can configure
multiple application monitors and associate them with one or more
application controllers.
All fields on this page are inactive until you specify information
for the Application Monitor Name field, then
all fields are enabled.
Fields
- Monitor type
- Select whether the monitor type you want to create is a Process
monitor or a Custom monitor.
- Application monitor name
- Specify a unique name for the new application monitor. The name
you specify must consist of a minimum of one alphanumeric character
and a maximum of 64 alphanumeric characters. You can use alphabetic
characters of A - Z and a - z, numbers of 0 - 9, as well as underscore
(_) characters. A name cannot begin with a number and cannot be a PowerHA™ reserved word.
- Process monitor
- Specify the full path and file name of one or more processes to
user for checking application status. This option is available only
when you select Process Monitor as the Monitor
Type for the application monitor.
- Monitor script
- Specify the full path and file name of a method to user for checking
application status. This option is available only when you select Custom
Monitor as the Monitor Type for
the application monitor.
- Run monitor
- Select the mode for the new monitor to use for monitoring the
application:
- Long-Running Monitoring
- Select this mode to have the application monitor periodically
check that the application controller is running successfully. The
checking frequency is set by means of the Monitor Interval. The monitor
begins checking the application controller after the specified stabilization
interval expires, the resource group that owns the application controller
is marked as online, and the cluster has stabilized. This is the default
mode.
- Startup Monitoring
- Select this mode to have the application monitor check that the
application controller has successfully started within the specified
stabilization interval. Select this mode if you are configuring an
application monitor for an application that you plan to include in
a parent resource group in a parent-child dependency, or that you
plan to include in a target resource group in a start after dependency.
This is in addition to other monitors that you may need for dependent
resource groups.
- Both
- Select this mode to have the application monitor check that the
application controller has successfully started within the specified
stabilization interval, and to periodically monitor that the application
controller is running after the stabilization interval has passed.
- Action on application failure
- Select the type of action you want the new monitor to take after
all attempts to restart the application controller have been exhausted.
You can select one of the following actions: Choices are 'notify'
and 'fallover'. If notify is selected, no further action will be taken
after running the notify method. If fallover is selected, the resource
group containing the monitored application will be moved to another
node in the cluster.
- Notify
- Select this option to have the application monitor take no further
action after running the notify script. When you select this option,
you must also specify a Notify script.
- Fallover
- Select this option to move the resource group that contains the
monitored application to another node in the cluster.
- Notify script
- Specify full path and file name of a user-defined method to perform
notification when a monitored application fails. This method executes
each time an application is restarted, fails completely, or falls
over to the next node in the cluster. You must specify this information
when you Notify as the action to take when
an application fails. It is strongly recommended that you configure
this method.
Note: Notify scripts are run only on failure for long
running monitors, regardless of the Action on application
failure option that you selected.
- Cleanup script
- Specify the full path and file name of the script to run to stop
the application. The default script to use is the stop method defined
for the application controller when the controller was configured.
If you have multiple application controllers, specify the stop script
that is used for the associated application controller to which this
monitor applies. If you are configuring a monitor to used only in
the startup monitoring mode, you do not need to specify a cleanup
script; PowerHA SystemMirror
will not use it.
- Restart script
- Specify the full path and file name of the script to run to start
the application. The default script to use is the start method defined
for the application controller when the controller was configured.
If there are multiple application controllers, there is no default
script. If you are configuring a monitor to used only in the startup
monitoring mode, you do not need to specify a restart script; PowerHA SystemMirror will not
use it.
Actions
- Add Another
- Click Add Another to add another set of
fields so that you can create and configure another application monitor
for your custom resource group. All fields for the added application
monitor are inactive until you select the first field, typically the
name field. All fields for the added application monitor are inactive
until you specify information for the Application Monitor
Name field, then all fields are enabled.
- Remove
- Click Remove to remove the content from
the first set of application monitor fields and disable all fields
after the Application Monitor Name field. If
applied to an added application monitor on the page, this action removes
the entire set of fields for the added monitor.