Enable debug logging for EDOT SDKs

Stack Serverless Observability

You can enable debug logging for Elastic Distributions of OpenTelemetry (EDOT) SDKs to troubleshoot application-level issues.

Enabling debug logging can help surface common problems such as:

• Auto-instrumentation not attaching or being disabled
• Authentication or endpoint misconfigurations
• Unsupported framework or language version
• Sampling rate being set too low (resulting in missing spans)

Check your application logs for SDK-specific output and errors. If no logs appear at all, verify that:

• The SDK or agent is correctly installed and loaded
• The application runtime includes the correct path or classpath
• The environment variables are visible to the application process
• The logs are being written to the correct location

You can enable debug logging using environment variables.

For general EDOT Java agent debugging, try:

export ELASTIC_OTEL_JAVAAGENT_LOG_LEVEL=debug
java -jar your-app.jar

The output is captured span information from the agent itself, in a JSON format.

If you need to see and inspect the specific trace data your application is generating, use:

export OTEL_TRACES_EXPORTER=otlp,logging-otlp
java -jar your-app.jar

The output are the application’s traces in a JSON format.

By default, logs are written to stderr.

To enable debug logging, set the OTEL_PYTHON_LOG_LEVEL variable to debug:

export OTEL_PYTHON_LOG_LEVEL=debug

Run your application as usual, for example:

python your_application.py

To enable debug logging for the EDOT .NET agent, set:

export OTEL_LOG_LEVEL=debug

$env:OTEL_LOG_LEVEL="debug"

Set this environment variable before starting your app:

export OTEL_LOG_LEVEL=debug
node --import @elastic/opentelemetry-node your-app.js

$env:OTEL_LOG_LEVEL="debug"
node --import @elastic/opentelemetry-node your-app.js

This produces debug-level logs from the SDK itself.

If you also want to inspect the actual telemetry your app is generating, configure exporters to log traces, metrics, or logs to the console. For example:

export OTEL_TRACES_EXPORTER=otlp, console
export OTEL_METRICS_EXPORTER=otlp, console
node --import @elastic/opentelemetry-node your-app.js

While the EDOT PHP agent supports the standard OTEL_LOG_LEVEL variable, you must also configure at least one of the Elastic-specific sink options to direct logs to a destination:

• ELASTIC_OTEL_LOG_LEVEL_FILE
• ELASTIC_OTEL_LOG_LEVEL_STDERR
• ELASTIC_OTEL_LOG_LEVEL_SYSLOG

Refer to Logging configuration for more details.

For deeper troubleshooting, you can also enable diagnostic data collection. For example:

export ELASTIC_OTEL_DEBUG_DIAGNOSTIC_FILE=/tmp/php_diag_%p_%t.txt php test.php

Ensure the file path is writable by the PHP process. If multiple PHP processes are running, use directives in the diagnostic file name to generate unique files and prevent overwriting. You can use:

• %p to insert the process ID

• %t to insert the UNIX timestamp

After setting the variable, restart the PHP process you're collecting diagnostics for, then send an HTTP request or run a script (for PHP-CLI).

The collected information includes:

• Process ID and parent process ID

• User ID of the worker process

• Loaded PHP extensions

• Output from the phpinfo() function

• Memory usage and maps (/proc/{{id}}/maps and /proc/{{id}}/smaps_rollup)

• Process status (/proc/{{id}}/status)

Disable diagnostic collection when you're done by unsetting the variable or restoring the previous configuration.

To learn how to enable debug logging for the EDOT Collector, refer to Enable debug logging for EDOT Collector.