Tracing Python Applications
Incident Management is now generally available! Incident Management is now generally available!

Tracing Python Applications

Compatibility Requirements

Python versions 2.7+ and 3.5+ are supported. For a full list of supported libraries, visit the Compatibility Requirements page.

Installation and getting started

Follow the Quickstart instructions within the Datadog app for the best experience, including:

  • Step-by-step instructions scoped to your deployment configuration (hosts, Docker, Kubernetes, or Amazon ECS).
  • Dynamically set service, env, and version tags.
  • Enable the Continuous Profiler, ingesting 100% of traces, and Trace ID injection into logs during setup.

Otherwise, to begin tracing applications written in Python, install the Datadog Tracing library, ddtrace, using pip:

pip install ddtrace

Then to instrument your Python application use the included ddtrace-run command. To use it, prefix your Python entry-point command with ddtrace-run.

For example, if your application is started with python app.py then:

ddtrace-run python app.py

Configure the Datadog Agent for APM

Install and configure the Datadog Agent to receive traces from your now instrumented application. By default the Datadog Agent is enabled in your datadog.yaml file under apm_enabled: true and listens for trace traffic at localhost:8126. For containerized environments, follow the links below to enable trace collection within the Datadog Agent.

  1. Set apm_non_local_traffic: true in your main datadog.yaml configuration file

  2. See the specific setup instructions to ensure that the Agent is configured to receive traces in a containerized environment:


  1. After having instrumented your application, the tracing client sends traces to localhost:8126 by default. If this is not the correct host and port change it by setting the below env variables:

DD_AGENT_HOST and DD_TRACE_AGENT_PORT.

You can also set the hostname and port in code:

import os
from ddtrace import tracer

tracer.configure(
    hostname="custom-hostname",
    port="1234",
)

To set up Datadog APM in AWS Lambda, see the Tracing Serverless Functions documentation.

Tracing is available for a number of other environments, such as Heroku, Cloud Foundry, AWS Elastic Beanstalk, and Azure App Services Extension.

For other environments, please refer to the Integrations documentation for that environment and contact support if you are encountering any setup issues.

For more advanced usage, configuration, and fine-grain control, see Datadog’s API documentation.

Configuration

When using ddtrace-run, the following environment variable options can be used:

Environment VariableDefaultDescription
DD_TRACE_DEBUGfalseEnable debug logging in the tracer.
DATADOG_PATCH_MODULESOverride the modules patched for this application execution. It should follow the format: DATADOG_PATCH_MODULES=module:patch,module:patch....

It is recommended to use DD_ENV, DD_SERVICE, and DD_VERSION to set env, service, and version for your services. Refer to the Unified Service Tagging documentation for recommendations on how to configure these environment variables.

Environment VariableDefaultDescription
DD_ENVSet the application’s environment, for example: prod, pre-prod, staging. Learn more about how to setup your environment. Available in version 0.38+.
DD_SERVICEThe service name to be used for this application. The value is passed through when setting up middleware for web framework integrations like Pylons, Flask, or Django. For tracing without a web integration, it is recommended that you set the service name in code. Available in version 0.38+.
DD_VERSIONSet the application’s version, for example: 1.2.3, 6c44da20, 2020.02.13. Available in version 0.38+.
DD_TAGSA list of default tags to be added to every span, profile, and runtime metric, for example: layer:api,team:intake. Available in version 0.38+.
DD_TRACE_ENABLEDtrueEnable web framework and library instrumentation. When false, the application code doesn’t generate any traces.
DD_AGENT_HOSTlocalhostOverride the address of the trace Agent host that the default tracer attempts to submit traces to.
DATADOG_TRACE_AGENT_PORT8126Override the port that the default tracer submit traces to.
DD_TRACE_AGENT_URLThe URL of the Trace Agent that the tracer submits to. Takes priority over hostname and port, if set. Supports Unix Domain Sockets in combination with the apm_config.receiver_socket in your datadog.yaml file, or the DD_APM_RECEIVER_SOCKET environment variable.
DATADOG_PRIORITY_SAMPLINGtrueEnable Priority Sampling.
DD_LOGS_INJECTIONfalseEnable connecting logs and trace injection.

Further Reading