Background information

Review the background information to learn about thresholds, predefined thresholds for your agents, the resource groups that they are assigned to, and customizing thresholds.

Predefined thresholds

Your monitoring agents come with predefined thresholds that are enabled and started with the agent. The first time that you open the Threshold Manager after agent installation, the thresholds that are listed for the selected data source type are the predefined thresholds. These predefined thresholds are assigned to the default system resource group for the agent and shown in the Assigned groups column.

If you edit a predefined threshold, such as to change the name or condition, the threshold is no longer treated as a predefined threshold but considered a custom threshold. However, you can change the assigned resource group for a predefined threshold from the default system group to a user-defined group and it remains a predefined threshold.

If you prefer not to use the predefined thresholds, you can turn them off in the Advanced Configuration page (see Thresholds Enablement). Disabling the predefined thresholds doesn't remove them from the Threshold Manager; it only removes their group assignment, rendering them inactive. After disabling the predefined thresholds, you can open the Threshold Manager and see that the Assigned groups column is empty for every predefined threshold (see Examples of disabled thresholds).

You can enable the threshold as a custom threshold by assigning it to any available resource group.

Custom thresholds

New thresholds that you create are custom thresholds, as indicated in the Threshold Manager Origin column. If you edit a predefined threshold, it also becomes a custom threshold and its origin changes from Predefined to Custom.

Execute command

After an event is opened for a threshold that evaluates to true, you can have a command or script of commands run automatically. For example, you might want to log information, trigger an audible beep, or stop a job that is overusing resources when an event is opened. The command or script is run on the system of the monitoring agent that opened the event.

The command uses the following syntax:

&{data_set.attribute}

where data_set is the data set name and attribute is the attribute name as shown in the Threshold Editor. If the data set or attribute name contains a space, replace with an underscore. The data_set must be the same data set that you select in the Data set selection field.

The following example shows how you can pass the disk name parameter to your managed resource:

/scripts/clean_logs.sh &{KLZ_Disk.Disk_Name}

You can pass in one or more attributes from the data set. If specified, multiple attributes are passed into the command in order ($1, $2, and so on).

You must ensure the script or programs executed by the command are installed on the agent system since Cloud APM does not provide a mechanism to distribute scripts or programs. The command runs from the command line with the same user account that the agent was started with. Ensure the user that starts the agent has permission to execute the command. For example, if the agent is running as root, then root runs the command on the managed system.

The following options control how often the command is run:

• Select On first event only if the data set returns multiple rows and you want to run the command for only the first event occurrence in the data sample. Clear the check box to run the command for every row that causes an event.
• Select For every consecutive true interval to run the command every time the threshold evaluates to true. Clear the check box to run the command when the threshold is true, but not again until the threshold evaluates to false, followed by another true evaluation in a subsequent interval.

Resource groups

Resource groups represent a collection of managed systems and control how thresholds are distributed. You assign a threshold to the resource group that includes the managed systems where you want it to run.

All predefined thresholds have a default resource group assignment, which is the system defined group for the agent type, such as Db2® and Microsoft IIS.

You can create custom resource groups and select the managed systems to include in each group. You can have multiple agent types in a custom resource group; thresholds that are assigned to the group are distributed only to the managed systems of the same agent type. For example, a threshold that is created with Linux OS attributes and assigned to a resource group of Linux OS, MongoDB, and Python managed systems, is distributed to only the Linux OS managed systems.

For more information, see Resource Group Manager.

Application Performance Dashboard event status

The status severities that are shown in the Application Performance Dashboard indicate the highest event severity of the selected application, group, subgroup, and managed system instance.

After you select an application from the navigator or from a summary box in the All My Applications dashboard, a tabbed dashboard presents different facets of your application. The Events tab provides information about the events for the selected navigator item, as described in Event Status.

Threshold changes affect other thresholds that are assigned to the same monitoring agent

After you create, modify, or delete a threshold definition or change the list of thresholds that are distributed to a monitoring agent, all sampled events are closed for the agents that the threshold is distributed to. After the event closure, the monitoring agents reopen events for any threshold conditions that evaluate to true. On the Cloud APM console, the closed events disappear from the console until they are reopened with a new Timestamp value. If you are receiving email notifications for events, you receive close event and open event email notifications.

Consider, for example, that you have a custom resource group named Site Systems with Linux OS and WebSphere Applications thresholds and agents assigned. You create a new Linux OS threshold and assign it to Site Systems. Any open sampled events on the Linux OS agents that are assigned to Site Systems are closed. Then the sampled events are reopened if the threshold conditions are still true.