Method trimming and stack traces
The App Visibility agent uses the following techniques to determine which methods to display:
Trimming (agent for Java, only)
Trimming is a process that results in smaller call trees, more focused error isolation, and a reduction in resource usage (including CPU, memory, and outbound bandwidth on the agent side, and inbound bandwidth and data-handling on the App Visibility collector and portal side). Trimming occurs during recording of a transaction on a JEE. Method request trees in the code section are trimmed by default, meaning that they contain only branches ending with an "interesting" method. A method is "interesting" when at least one of the following criteria applies:
- The method's duration is longer than the trimming.threshold property configured in the Agent policy file.
- The method resulted in an exception error.
- The method is located on a branch that took more time than expected.
- The method is an exit point.
Any methods that lead to an interesting method are also shown.
You configure trimming, and turn it on and off, through the Agent policy file. To turn it on and off, you use the use.runtime.trimming property.
Stack traces for exceeded thresholds
The App Visibility agent displays the following types of methods:
- Methods that are recognized as interesting before they are invoked. Detailed information is captured and displayed for these methods, according to policy level and recording rules. See Modifying an App Visibility agent policy file to collect and monitor application information and consult with App Visibility Customer Support to configure App Visibility recording settings.
- Methods that exceed a defined threshold. The App Visibility agent did not recognize these methods as interesting before they were invoked. Such methods are captured as part of stacks leading to service-level agreement (SLA) breaches. No details are captured for these methods.
If the instance has latency violations, the full stack trace is shown by default. You can hide the stack trace by clearing Show stack trace for exceeded thresholds check box.