Implementation:Apache Airflow Stats Initialize

Knowledge Sources	Apache Airflow
Domains	Observability, Python_API
Last Updated	2026-02-08 00:00 GMT

Overview

Concrete tool for initializing and emitting Airflow metrics provided by the Stats metaclass and backend loggers.

Description

The Stats class uses a metaclass (_Stats) to lazily initialize the appropriate metrics backend. Stats.initialize() selects between StatsD, OpenTelemetry, or Datadog loggers based on configuration flags. All Airflow components emit metrics through the Stats facade, which delegates to the configured backend.

Usage

Stats is initialized automatically by the Airflow runtime. Metrics configuration is set in airflow.cfg under the [metrics] section.

Code Reference

Source Location

• Repository: Apache Airflow
• File: shared/observability/src/airflow_shared/observability/metrics/stats.py

Signature

class _Stats(type):
    factory: Callable[[], StatsLogger | NoStatsLogger] | None = None
    instance: StatsLogger | NoStatsLogger | None = None

    def initialize(
        cls,
        *,
        is_statsd_datadog_enabled: bool,
        is_statsd_on: bool,
        is_otel_on: bool,
    ) -> None:
        """Initialize the metrics backend based on configuration."""
        ...

    @classmethod
    def get_constant_tags(cls, *, tags_in_string: str | None) -> list[str]:
        ...

class Stats(metaclass=_Stats):
    """Empty class for Stats — metaclass injects the right backend."""

Import

from airflow_shared.observability.metrics.stats import Stats

I/O Contract

Inputs

Name	Type	Required	Description
is_statsd_on	bool	Yes	Enable StatsD metrics
is_otel_on	bool	Yes	Enable OpenTelemetry metrics
is_statsd_datadog_enabled	bool	Yes	Enable Datadog StatsD

Outputs

Name	Type	Description
Metrics	StatsD/OTel/Datadog	Counters, gauges, timers emitted to configured backend
Traces	OTel spans	Distributed traces (if OTel enabled)

Usage Examples

Helm Chart Metrics Configuration

# values.yaml — Enable StatsD with Prometheus
statsd:
  enabled: true
  port: 9125
  prefix: airflow

# Or via airflow.cfg
# [metrics]
# statsd_on = True
# statsd_host = localhost
# statsd_port = 9125
# statsd_prefix = airflow

Related Pages

Implements Principle

• Principle:Apache_Airflow_Monitoring_Observability

Requires Environment

• Environment:Apache_Airflow_Kubernetes_Helm_Environment