How to Enable Debug Mode for AppDynamics Controller Logs (Jetty-based)

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This guide explains how to enable debug-level logging in the Jetty-based AppDynamics Controller. This is especially helpful when troubleshooting issues across key components like Business Transactions, Metrics, Events, and more.

It is intended for system administrators managing self-hosted AppDynamics environments who need granular log details without restarting services.

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Prerequisites

• Admin or root access to the Controller host machine

• Familiarity with XML configuration files

• Basic understanding of Java logging levels (e.g., INFO, DEBUG, TRACE)

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Step-by-Step Instructions

Step 1: Log in to the Controller Server

SSH into the host where the AppDynamics Controller is installed:

ssh user@<controller-host>

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Step 2: Locate the logback.xml File

Navigate to the logging configuration file:

cd <controller_home>/appserver/jetty/resources/

The file you need to edit is:

logback.xml

🔎 This file controls logging levels for all Controller components using the Logback framework.

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Step 3: Modify Log Level by Component

1. Open the file in a text editor:

   vi logback.xml

2. Find or add the logger entry for the desired component. For example, to enable DEBUG logs for Hibernate:

   <logger name="com.hibernate" level="DEBUG"/>

3. To enable debug logging for a common Controller component (e.g., Business Transactions or Metrics), you might add:

   <logger name="com.singularity.BT" level="DEBUG"/>
   <logger name="com.singularity.metrics" level="DEBUG"/>

4. Save and close the file.

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Step 4: Wait for Changes to Take Effect

You do not need to restart the Controller. Log level changes made in logback.xml take effect within a few minutes automatically.

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Troubleshooting

Logs Not Updating with New Verbosity

Solution:

• Ensure your XML syntax is valid and enclosed within <configuration> tags

• Double-check that the logger name is spelled correctly

• Wait a few minutes—Logback applies changes dynamically

Excessive Log File Growth

Solution:

• Return the level to INFO or WARN after troubleshooting

• Enable log rotation via configuration or scheduled scripts

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Additional Notes / Best Practices

• Use targeted component loggers to avoid noise. Some common loggers include:

  • com.singularity.BT for Business Transactions

  • com.singularity.metrics for Metrics

  • com.singularity.snapshots for Snapshots

  • com.singularity.orchestration for Orchestration

• Avoid leaving DEBUG or TRACE logging on for long periods in production environments

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Conclusion

By editing the logback.xml file, you can enable debug logging in the Jetty-based AppDynamics Controller without restarting services. This allows you to collect detailed diagnostic data during issues while maintaining flexibility and control.

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FAQ

Q: Do I need to restart the Controller after editing logback.xml?
A: No, changes are picked up automatically within a few minutes.

Q: Where are the debug logs stored?
A: Logs are written to the standard Controller log directory, typically:

<controller_home>/logs/server.log

Q: Can I enable debug mode for just one module?
A: Yes, by specifying the exact logger (e.g., com.singularity.metrics) in logback.xml.