TrueSight Synthetic Monitor generates events based on a system of metrics and metric rules. The metrics measure the results of a transaction. Metric rules use the metrics to define thresholds for issuing events. Four global metric rules, applicable to all transactions, are included out-of-the-box, and more specific metric rules can be defined on application, Execution Plan, transaction, and location levels. TrueSight Synthetic Monitor also includes a less-robust event generation mechanism using SLAs.
This topic describes the following:
Metrics are measurements of a transaction. TrueSight Synthetic Monitor continuously measures the results of your synthetic transactions and compiles statistics for each metric. You can then use these statistics data to set event thresholds for the metrics.
TrueSight Synthetic Monitor includes two types of metrics:
The following table describes the four basic metrics that are available for all transactions:
|Performance||End-to-end latency of the transaction measured in seconds|
Number of availability errors in the transaction
Availability errors occur when the application does not respond, or when the application responds with an error that indicates it is unavailable. The number of Availability errors provides information regarding whether the application is running and whether it provides basic responsiveness to client requests.
Number of accuracy errors in the transaction
Accuracy errors are calculated with the assumption that monitored applications are working as designed and that the information transmitted to clients is correct. Functions that can be evaluated to determine accuracy include link checking, content validation, title validation, and response data verification. If a monitoring script contains customized functions that are used to ascertain system accuracy, those functions are factored in as well.
Number of execution errors in the transaction
An execution error indicates that there were problems with the script execution. It does not indicate anything about the health of the application.
If you have Execution errors configures to be counted as Availability errors (see Reclassifying Synthetic Monitor Execution errors and Accuracy errors as Availability errors for more details), this metric is irrelevant.
In addition to the basic metrics, page timers and custom timers that are defined in your scripts are measured. You can define rules based on the results measured for the timers. Page timer and custom timer metrics are measured in seconds. The Execution Plan must have run at least once for the timers defined for that Execution Plan to be available as metrics.
A metric rule is a set of definitions for generating events. Based on the events generated by the metric rules, notifications are issued, the status of the application is updated accordingly, and the events can be viewed on the Synthetic Health tab.
Status in the Application View tab is not updated based on synthetic metric rules.
A metric rule consists of a metric, thresholds, and scope.
There are four global metric rules, that correspond to the basic metrics. The four global metric rules are automatically applied to Any application, Any Execution Plan, Any transaction, and Any location. This cannot be modified.
The following global metric rules are included out-of-the-box:
You can modify the thresholds, and notification settings of the global metric rules, or activate/deactivate them. You cannot delete global metric rules.
You can define more specific metric rules at the application, Execution Plan, transaction, or location level. More specific metric rules always override more general metric rules, and only one metric rule is applied to a given transaction for each metric. For example, if you define an Availability metric rule for a specific application, the global Availability metric rule is no longer applied to that application. If you define an additional Availability metric rule for one of the application's Execution Plans. Only the Execution Plan-level Availability metric rule is applied to that Execution Plan. The application-level metric rule is applied to all other Execution Plans for that application, and the global Availability metric rule is applied to other applications.
Each metric rule must apply to a unique combination of application, Execution Plan, transaction, metric, and location.
For example, if you define a metric rule that measures Performance for:
You cannot define another Performance metric rule for the same combination of
You can deactivate or activate any metric rules, including the global metric rules. Deactivating a metric rule means that no events are generated and no notifications are issued by the deactivated metric rule. If a metric rule is deactivated, and a more general metric rule covering the same metric is active, the more general metric rule takes effect. For example, if an Execution Plan-level Availability matric rule is disabled, an application-level metric rule may be applied instead.
TrueSight Synthetic Monitor includes SLA definitions that can generate events.