Overview

Runtime metrics monitor your application’s memory usage, garbage collection, and parallelization. Datadog tracing libraries automatically collect these metrics for supported environments and send them to the Datadog Agent.

These metrics help you identify bottlenecks, troubleshoot performance issues, and optimize resource utilization. By viewing runtime metrics alongside traces and logs, you gain comprehensive visibility into your application’s health and performance.

Compatibility

Runtime metrics are available for several programming languages and runtimes, with varying levels of support and configuration options.

net localgroup "Performance Monitor Users" "IIS APPPOOL\DefaultAppPool" /add

Setup instructions

To set up runtime metrics, you need to configure both the Datadog Agent and your application.

1. Configure the Datadog Agent

Enable DogStatsD for the Agent. By default, the Datadog Agent is configured to ingest metrics with UDP over port 8125.

Container-specific configuration

When running the Agent in containerized environments, additional configuration is required:

1. Set dogstatsd_non_local_traffic: true in your main datadog.yaml configuration file, or set the environment variable DD_DOGSTATSD_NON_LOCAL_TRAFFIC=true.
2. Follow these container-specific setup instructions:

3. Set DD_SITE in the Datadog Agent to to ensure the Agent sends data to the correct Datadog location.

2. Configure your application

Configure runtime metrics in your application using environment variables. Some languages also support configuring runtime metrics directly in code.

Environment variables

Use the following environment variables to configure runtime metrics in your application:

DD_RUNTIME_METRICS_ENABLED

Default: true for Java, false for all other languages
Description: Enables the collection of runtime metrics. Metrics are sent to the Datadog agent, as configured for the instrumented application.

DD_RUNTIME_METRICS_RUNTIME_ID_ENABLED

Default: true for Java, false for Node.js, Ruby, and Python. Does not exist for .NET and Go; the runtime_id is always reported.
Description: Enables enhanced runtime metrics, providing a runtime_id tag along with every metric. The runtime_id represents the application’s process identifier and allows you to directly correlate runtime metrics with individual running applications.

DD_AGENT_HOST

Default: localhost
Description: Sets the host address for the tracing library’s metric submission. Can be a hostname or an IP address.

DD_DOGSTATSD_PORT

Default: 8125
Description: Sets the port for the tracing library’s metric submission.

Code-based configuration

In addition to environment variables, some languages support configuring runtime metrics directly in code.

from ddtrace.runtime import RuntimeMetrics
RuntimeMetrics.enable()

# config/initializers/datadog.rb
require 'datadog/statsd'
require 'datadog' # Use 'ddtrace' if you're using v1.x

Datadog.configure do |c|
  c.runtime_metrics.enabled = true

  # Optionally, you can configure the DogStatsD instance used for sending runtime metrics.
  # DogStatsD is automatically configured with default settings if `dogstatsd-ruby` is available.
  # You can configure with host and port of Datadog agent; defaults to 'localhost:8125'.
  c.runtime_metrics.statsd = Datadog::Statsd.new
end

// Basic configuration
tracer.Start(tracer.WithRuntimeMetrics())

// With custom DogStatsD address
tracer.Start(
  tracer.WithRuntimeMetrics(),
  tracer.WithDogstatsdAddr("custom-host:8125")
)

const tracer = require('dd-trace').init({
  // Other tracer options...
  runtimeMetrics: true
})

Dashboards

After setup is complete, you can view runtime metrics in:

• The instrumented service’s details page
• The flame graph Metrics tab
• Default runtime dashboards

Troubleshooting

• To associate runtime metrics within flame graphs, ensure the env tag (case-sensitive) is set and matching across your environment.
• For runtime metrics to appear on the service page when using Fargate, ensure that DD_DOGSTATSD_TAGS is set on your Agent task, and that the configured env tag matches the env of the instrumented service.

Data collected

Each supported language collects a set of runtime metrics that provide insights into memory usage, garbage collection, CPU utilization, and other performance indicators.

Further reading

Additional helpful documentation, links, and articles:

Correlate your logs and tracesDOCUMENTATION Manually instrument your application to create traces.DOCUMENTATION Explore your services, resources, and tracesDOCUMENTATION