How can I troubleshoot Agent issues?
Table of Contents
How do I delete an abandoned Machine Agent when it is not attached to any APM agents?
There are two ways to delete the abandoned machine agent, either from controller UI by creating a dummy application or through a manual step to delete the agent from the database. See the steps for either process under Delete abandoned machine agent.
What is the best way to set up alerts for App Agent Status and Machine Agent Status?
There are two solutions for this, found in Agent Status on .NET
What does the error message "account key doesn't match with the current account for machine id" mean?
The "account key doesn't match with the current account for machine id" message indicates that the account key generated by the AppDynamics Controller during the registration may be now changed. This could happen if you migrate the Controller without shutting down the agents.
Restart the agent to resolve the error.
How do I resolve an Agent causing overhead or crash?
Follow these steps to troubleshoot:
- Check the agent logs for any communication errors between Agent and Controller.
- Make sure Automatic Leak Detection (ALD) has not been set to "on" for a long time.
- The Agent requires 30 MB of permgen space. Set this parameter (
-XX:MaxPermSize=<value>) to a higher value (256m, at least) and try again.
- Get the crash report and heap dump for analysis.
- Check the agent log level is set to INFO (default log level value if not changed to debug/trace) at
agent_dir/conf/logging/log4j.xml.
- Make sure periodic sampling and occurrence request sampling is not set to a low value (default 100 requests and 10 min, update/disable as per requirement).
- Check the agent logs for any logged repetitive exceptions.
- Disable the agent from the node dashboard and monitor whether the heap usage overhead/crash is still happening to find whether agent/webapp instrumentation is raising the issue.
When requesting Agent logs, the log status times out
On requesting Agent logs in <Application> -> Servers -> App Servers -> <tier> -> <node> -> Agents, you may experience a timeout of the log status.
One possible cause is that someone first requested the log and reset the agent before the log sends to the Controller. To resolve the error, reset the Agent before requesting the agent log.
Can I assign a Machine Agent to multiple applications on the same server?
To assign a Machine Agent to multiple applications on the same server, run one Machine Agent process for each application on a machine.
- Add the VM parameter (
-Dappdynamics.agent.uniqueHostId=<<some unique value per application>>) to both Machine Agent and the App Agent.
- Provide the same value to the machine - app agent pair.
For example, if you have 2 nodes (n1 and n2 ) reporting to applications (a1 and a2). Let's say m1 and m2 are your machine agents for the corresponding nodes. You will need to pass -Dappdynamics.agent.uniqueHostId=a1 for n1 and m1. and -Dappdynamics.agent.uniqueHostId=a2 for n2 and m2.
- The
uniqueHostId value can be any unique value but should be different for each application.
- Restarting the JVMs with the above options. you should see machine agents associating with corresponding applications.
How do I export a list of Agents and details into a spreadsheet?
Other than viewing the list of AppDynamics Agents in Settings, can I get a list of those Agents and their details in a spreadsheet format?
It's not out of the box, but there is a workaround:
- Create a small program that can read
/controller/rest/applications
- List all applications and get list of nodes from
/controller/rest/applications/<application-name|application-id>/nodes
- Go to the AppDynamics Agents page.
- Take a screenshot of the AppDynamics Agents page
- Trim the picture and copy it to One Note
- Right-click the picture in OneNote and select Copy to Text
More Troubleshooting Guides:
Published 2/26/2018
