Health and Health Rules
"Health" throughout the AppDynamics UI refers to the extent to which the component being monitored is operating within the acceptable limits defined by health rules. Health rules allow you to automate pro-active monitoring and problem mediation in your managed environment. By default, AppDynamics provides a set of basic health rules, which you can extend, add to, or remove as your needs dictate.
A health rule violation exists when the conditions that define the rule are true. For example, you might have defined a health rule condition that states that a CPU%Busy rate of more than 90% on any node is a critical condition. If the rate on a node then goes over 90%, the health rule is said to "violate" and the AppDynamics UI displays a notification of that violation.
Because there is a set of default health rules, you may see health rule violations reported for your application even if you have not set up your own health rules. If you see violations reported for the APPDYNAMICS_DEFAULT_TXT business transaction, these are for default health rule violations in the All Other Traffic business transaction. If you are not interested in monitoring these business transactions, you may want to examine your business transaction setup. See Organizing Traffic as Business Transactions.
Troubleshoot Heath Rule Violations
To start troubleshooting health rule violations, you can:
- Get a list of all the health rule violations by clicking Troubleshoot -> Health Rule Violations.
- Click on a particular health rule violation you see displayed in the UI.
You can access the list of health rule violations in your application for the selected time range.
To find all health rule violations
1. In the left navigation pane, click Troubleshoot -> Health Rule Violations.
The list of health violations displays.
2. Select View All Health Rule Violations in the Time Range or View Only Health Rule Violations Open Now.
It is possible that health rule violations that were reported are no longer open because remedial action has been taken or performance has improved on its own.
3. To see the filters click Show Filters. To hide them click Hide Filters.
With the filters showing in the left filters panel you can select the health rule violations that you want to troubleshoot. You can view all health rule violations or expand the nodes in the tree to select by health rule type (such as business transaction health rules or node health rules) or affected entity (such as business transaction, tier or node).
You can filter health rule violations by entering the name of the health rule in the search field on the upper right.
The health rule violations are displayed in the right panel, with their status, description, start time, end time and duration (if ended), and the affected entity.
To troubleshoot a health rule violation
Once you have located the violation you are interested in, you can get more information in three ways:
- To see the health rule definition that was violated for a specific violation, find the health rule violation in the list and in the Health Rule column, click the link to the health rule configuration. The Edit Health Rule window for the specific definition appears.
- To see the dashboard for the entity, such as a business transaction or a node, affected by the violation, click the link to the entity in the Affects column. The Transaction Flow Map appears.
- To troubleshoot a specific health rule violation, select the health rule violation row from the list and click Health Rule Violation Details in the top bar.
The Health Rule Violation Event window displays a summary of the violation and any actions that were executed to respond to it.
You can click the View Dashboard During Health Rule Violation in the details window to view the dashboard at the time the violation occurred. The time range in this and all other dashboards is set to the time range of the health rule violation. From the dashboard you can get an overall picture of the application at the time of the violation. If you select the Transaction Snapshots tab you get a list of relevant snapshots which allows you to drill down to the root cause of the problem. See Transaction Snapshots for more information.
To see health rule status in the UI
Across the UI, health rule status is color-coded: green is healthy; yellow/orange is a warning condition; and red is a critical condition. If you see a health rule violation reported in the UI, you can click it to get more information about the violation.
Here are the health summary bars on the dashboards:
There is a health column in the business transaction list:
In the Events panel on the dashboards, health violations are displayed as events.
To see a summary of the violation, click a health rule violation from the Events list, then select the violation you are interested in from the list that appears. Click View Event Details in the top bar and the Health Rule Violation Started window appears. It displays detailed information and a link to the appropriate dashboard at the time of the violation. If any Policy actions were executed in response to the violation, they are also displayed.