OpenTelemetry Prometheus Exporter

This library allows export of metrics data to Prometheus.

Usage

The OpenTelemetry Prometheus Exporter allows export of OpenTelemetry metrics to Prometheus.

from prometheus_client import start_http_server

from opentelemetry.exporter.prometheus import PrometheusMetricReader
from opentelemetry.metrics import get_meter_provider, set_meter_provider
from opentelemetry.sdk.metrics import MeterProvider

# Start Prometheus client
start_http_server(port=8000, addr="localhost")

# Exporter to export metrics to Prometheus
prefix = "MyAppPrefix"
reader = PrometheusMetricReader(prefix=prefix)

# Meter is responsible for creating and recording metrics
set_meter_provider(MeterProvider(metric_readers=[reader]))
meter = get_meter_provider().get_meter("myapp", "0.1.2")

counter = meter.create_counter(
    "requests",
    "requests",
    "number of requests",
)

# Labels are used to identify key-values that are associated with a specific
# metric that you want to record. These are useful for pre-aggregation and can
# be used to store custom dimensions pertaining to a metric
labels = {"environment": "staging"}

counter.add(25, labels)
input("Press any key to exit...")

API

class opentelemetry.exporter.prometheus.PrometheusMetricReader(disable_target_info=False, prefix='', scope_info_enabled=True, *, registry=<prometheus_client.registry.CollectorRegistry object>)[source]

Bases: MetricReader

Prometheus metric exporter for OpenTelemetry.

Parameters:

  • disable_target_info (bool) – Whether to disable the target_info metric.

  • scope_info_enabled (bool) – Whether to include instrumentation scope labels on exported metrics. Scope labels are exported by default.

  • prefix (str) – Prefix added to exported Prometheus metric names.

shutdown(timeout_millis=30000, **kwargs)[source]

Shuts down the MetricReader. This method provides a way for the MetricReader to do any cleanup required. A metric reader can only be shutdown once, any subsequent calls are ignored and return failure status.

When a MetricReader is registered on a MeterProvider, shutdown() will invoke this automatically.

Return type:

None

Installation

The OpenTelemetry Prometheus Exporter package is available on PyPI:

pip install opentelemetry-exporter-prometheus

Usage

The Prometheus exporter starts an HTTP server that collects metrics and serializes them to Prometheus text format on request:

from prometheus_client import start_http_server

from opentelemetry import metrics
from opentelemetry.exporter.prometheus import PrometheusMetricReader
from opentelemetry.sdk.metrics import MeterProvider
from opentelemetry.sdk.resources import SERVICE_NAME, Resource

# Service name is required for most backends
resource = Resource.create(attributes={
    SERVICE_NAME: "your-service-name"
})

# Start Prometheus client
start_http_server(port=9464, addr="localhost")
# Initialize PrometheusMetricReader which pulls metrics from the SDK
# on-demand to respond to scrape requests
reader = PrometheusMetricReader()
provider = MeterProvider(resource=resource, metric_readers=[reader])
metrics.set_meter_provider(provider)

Scope labels

By default, the Prometheus exporter adds instrumentation scope information as labels on every exported metric. These labels include otel_scope_name, otel_scope_version, and otel_scope_schema_url. Instrumentation scope attributes are exported with the otel_scope_ prefix:

from prometheus_client import start_http_server

from opentelemetry import metrics
from opentelemetry.exporter.prometheus import PrometheusMetricReader
from opentelemetry.sdk.metrics import MeterProvider

start_http_server(port=9464, addr="localhost")
reader = PrometheusMetricReader()
provider = MeterProvider(metric_readers=[reader])
metrics.set_meter_provider(provider)

meter = metrics.get_meter(
    "checkout",
    "1.2.3",
    schema_url="https://opentelemetry.io/schemas/1.21.0",
    attributes={"region": "us-east-1"},
)
counter = meter.create_counter("orders")
counter.add(1, {"environment": "production"})

The exported metric includes labels such as otel_scope_name="checkout", otel_scope_version="1.2.3", otel_scope_schema_url="https://opentelemetry.io/schemas/1.21.0", otel_scope_region="us-east-1", and environment="production".

To omit instrumentation scope labels from exported metrics, set scope_info_enabled to False:

reader = PrometheusMetricReader(scope_info_enabled=False)

Configuration

The following environment variables are supported:

  • OTEL_EXPORTER_PROMETHEUS_HOST (default: “localhost”): The host to bind to

  • OTEL_EXPORTER_PROMETHEUS_PORT (default: 9464): The port to bind to

Limitations

  • No multiprocessing support: The Prometheus exporter is not designed to operate in multiprocessing environments (see #3747).

References