It is important that you configure alerts appropriately to ensure that you do not miss any alerts or receive false alerts. 'Alert Sensitivity Tuning' (AST) helps you configure alerts with appropriate sensitivity. AST provides historical data for the metric or the baseline being configured and hence helps you visualize the impact of the alerting configuration. For more information, see Alert Sensitivity Tuning.
Create a Health Rule and Fine-tune Metric Evaluation
You can create a health rule to monitor the parameters of an application entity and fine-tune the sensitivity of a health rule using Alert Sensitivity Tuning (AST).
- In the entity (BT, SEP or remote services) UI, select an entity from the list.
- Right-click the entity and click Create new Health Rule. The Create Health Rule UI is displayed.
- Configure the health rule overview details. For more information, see Configure Heath Rule Details.
- In the Affected Entities panel, select the entities to be monitored.
- In the Critical Criteria panel, select +Add Condition.
- Configure the condition as follows:
- In the first field of the condition row, enter a name for the condition.
This name is used in the generated notification text and in the AppDynamics console to identify the violation.
- From the drop-down list below the Add Condition button, select Single Metric metric to evaluate the condition.
From the Value drop-down list, select a qualifier for the metric from the following options:
The minimum value reported across the configured evaluation time length. Not all metrics have this type.
The maximum value reported across the configured evaluation time length. Not all metrics have this type.
The arithmetic average of all metric values reported across the configured evaluation time length. This value is based on the type of metric.
The sum of all the metric values reported across the configured evaluation time length.
The number of times the metric value has been measured across the configured evaluation time length.
Group Count The number of nodes contributing to a metric value, generally relevant for application or tier level metrics.
The value for the current minute.
Click Select a Metric. Metric Selection window is displayed. The metric browser in the Metric Selection window displays metrics appropriate to the health rule.
Select a metric from the list for the business transaction. Click Select Metric.
A graphical view of the metric data for the last 8 hours is displayed.
If you want to view the metric data for 1 day or 3 days, you can select the time period using the drop-down menu.
From the drop-down list after the metric, select the type of comparison to evaluate the metric.
To limit the effect of the health rule to conditions during which the metric is within a defined range—standard deviations or percentages—from the baseline, select Within Baseline from the menu. To limit the effect of the health rule to when the metric is not within that defined range, select Not Within Baseline. Then select the baseline to use, the numeric qualifier of the unit of evaluation, and the unit of evaluation. For example:
Within Baseline of the Default Baseline by 3 Baseline Standard Deviations
To compare the metric with a static literal value, select < Specific value or > Specific Value from the menu, then enter the specific value in the text field. For example:
Value of Errors per Minute > 100
To compare the metric with a baseline, select < Baseline or > Baseline from the drop-down list, and then select the baseline to use, the numeric qualifier of the unit of evaluation, and the unit of evaluation. You can use the Baseline Standard Deviation or Baseline Percentage as the unit of evaluation. For example:
Maximum of Average Response Time is > Baseline of the Daily Trend by 3 Baseline Standard Deviations
See Dynamic Baselines for information about the baseline options.
Info title Baseline Percentages
The baseline percentage is the percentage above or below the established baseline at which the condition will trigger. For example, if you have a baseline value of 850 and you have defined a baseline percentage of > 1%, the condition is true if the value is
To prevent health rule violations from being triggered when the sample sets are too small, these rules are not evaluated if the load—the number of times the value has been measured—is less than 1000. For example, if a very brief time slice is specified, the rule may not violate even if the conditions are met, because the load is not large enough.
If you want the condition to evaluate to true whenever a configured metric does not return any data during the evaluation time frame, check the Evaluate to true on no data option.
This option does not affect the evaluation of the unknown in the case where there is no enough data for the rule to evaluate. For example, if the health rule is configured to evaluate the last 30 minutes of data and a new node is added, the condition evaluates to unknown for the first 30 minutes even if the Evaluate to true on no data box is checked.
If you want to define a 'Persistence Threshold' for the condition to reduce false alerts:
Select Trigger only when a violation occurs __ times in the last __ min(s).
Define the number of times metric performance data should exceed the defined threshold to constitute a violation.
If required, adjust the evaluation time frame by setting an alternate evaluation time frame.
You can define a persistence threshold for a condition only if you have defined an evaluation time frame of 30 minutes or less.
If you define a persistence threshold for a condition, the metric data is plotted directly on the AST graph. If you do not define a persistence threshold, a 'moving average' for the selected metric is plotted. For more information, see Why use 'moving average'?.
Specify the evaluation scope in the Critical Criteria and Warning Criteria panels, select the average of all nodes.
AST graphical view is displayed only when you set the health rule evaluation scope to 'average for all nodes'.
- If required. select the Warning Criteria panel and define warning conditions as described in step 6.
- Click Save. The health rule is saved.