Traces not showing up in the app

The most common reason for traces not being received by Datadog is an agent communication issue:

  • Ensure the Datadog agent is running and reachable over the network if not on the same host.

  • Ensure that ddtrace is configured with the hostname and port of the agent. See Configuration for the configuration variables.

To verify that a connection can be made to the agent with your environment variable configurations run the command ddtrace-run --info.

Failed to send traces… ConnectionRefusedError

Failed to send traces to Datadog Agent...: ConnectionRefusedError(111, 'Connection refused')

The most common error is a connection error. If you’re experiencing a connection error, please make sure you’ve followed the setup for your particular environment so that the tracer and Datadog agent are configured properly to connect, and that the Datadog agent is running:

If the above doesn’t fix your issue, the Datadog Agent also has a limit to the number of connections it can receive. This can be configured with the instructions here:

Service, Env, or Version not set

The service, env, and version tags are reserved tags in Datadog that allow unique capabilities in the Datadog UI for correlating and viewing data. In order to have all of the features Datadog provides, we’d recommend setting these tags.

The service tag is used for the scoping of application specific data across metrics, traces, and logs. If a service tag is not provided for the tracer, traces and trace metrics will appear under the name of the instrumented integration, e.g. flask for a Flask application.

The env tag is used for the scoping of the application’s data to a specific environment, e.g. env:prod vs env:dev.

For more information about the version tag please see:

To set service, env, and version properly for your environment, please see:

Still having issues?

If none of the above was able to resolve the issue then please reach out to Datadog support at Or view the other support options listed here: