This page covers how to enable object instance tracking on a node.
When you enable object instance tracking for a node, AppDynamics analyzes the heap to identify classes with the most instances on the heap. AppDynamics tracks the top 20 .NET framework classes and the top 20 application classes based upon the number of instances. Use object instance tracking to identify memory usage trends in classes with large numbers of instances.
To enable object instance tracking, you need one of the following permissions:
- Configure Memory Monitoring
- Configure Agent Properties
For information on AppDynamics Role Based Access Control, see Roles and Permissions.
Before You Begin
- The .NET Agent only supports object instance tracking for .NET 4 and later.
The .NET Agent Coordinator Service must be the same architecture as the monitored application. For example, a 64-bit coordinator with a 64-bit IIS application.
Enable Object Instance Tracking on a Node
- From the node dashboard, click the Memory tab.
- Click the Object Instance Tracking subtab.
Once the agent completes the heap analysis, AppDynamics begins to track the top 20 application classes and the top 20 system (core .NET) classes in the heap.
When you enable object instance tracking, the .NET application pauses during heap analysis and cannot process requests. Enable object instance tracking while you're diagnosing memory issues. Turn it off when you finish troubleshooting.
Identify Memory Usage Problems
Use the following guidelines to identify memory usage problems:
- The Controller resolution for object instances is one minute, but the .NET Agent agent only sends data every 10 minutes, so .NET memory appears as a series of peaks over time.
- It is normal for the controller to display 0 for the Current Instance Count and Shallow Size in between instance count collection times.
- Hover over a peak to display information about the instance count.
- Look for trends where the peaks increase in size from left to right which may indicate a memory leak.
Track Object Instances for Custom Classes
If you want to track a class that doesn't appear in the top 20 on the Object Instance Tracking tab, you can configure a specific class to track.
- On the Object Instance Tracking tab, click Configure Custom Classes to Track to navigate to the Configure Instrumentation > Memory Monitoring tab.
- Click Add. The Create New Instance Tracker window opens.
- Leave Enabled checked.
- Enter the fully qualified class name for the instance to track.
- Click Save.