About PHP Server Health
Health is an indicator of how actual performance compares to acceptable performance. Acceptable performance is defined by health rules which generate warning events for performance that may be and critical events for performance that definitely is of concern and requires investigation. A color other than green in the server health bar or in the icons in the Health tab in the app servers list indicates that health rule violation events exist.
For server health, AppDynamics provides predefined default health rules for CPU utilization and physical memory utilization.
Viewing Health Rule Violations
You can access information about health rule violations by clicking Troubleshoot-> Health Rule Violations in the left navigation pane or Server Health in the Server Health panel.
You can view the health rule violation details and the status of the violation:
Double-click on a health rule violation in the list to see details about the violation. From there you can view:
- the configuration for the health rule that was violated
- the node dashboard at the time of the health rule violation
- actions that were automatically executed (if any) in response to the health rule violation
Modifying an Existing Health Rule
Perhaps a predefined health rule is too restrictive, or not restrictive enough, for your application environment. For example the default health rule for CPU utilization triggers a warning event when a node exceeds 75% CPU utilization and a critical event when a node exceeds 90% utilization. You can modify these percentages as well as create your own health rules. Maybe the default setting is generating too many health rule violations and you want to change the configuration so that critical events are triggered when CPU utilization exceeds 95%.
To access the node health rule configuration window
Do one of the following:
- If you currently viewing a violation in the Health Rule Violation window, click the link to the health rule.
- In the left navigation pane:
1.Click Alert & Respond->Health Rules.
2 Double-click the the health rule in the health rule list.
To modify the conditions that trigger an existing health rule violation
1. In the Edit Health Rule window click the Critical Condition tab on the left.
2. Change the value in the specific value text field to another value.
3. Click Save.
4. In the Edit Health Rule window click the Warning Condition tab on the left.
5. Change the value in the specific value text field to another value.
6. Click Save.
You can also add more conditions required to trigger the health rule violation by clicking Add Condition. Or change the times at which the health rule is in effect, in the Overview tab. Or restrict the nodes and tiers affected by the health rule in the Affects tab. Or create entirely new health rules from scratch. See Health Rules and Configure Health Rules..