opentelemetry-exporter-cloudwatch-emf 0.2.4

OpenTelemetry metrics exporter for AWS CloudWatch using Embedded Metric Format (EMF)

OpenTelemetry CloudWatch EMF Exporter

An OpenTelemetry metrics exporter for AWS CloudWatch using Embedded Metric Format (EMF).

This is an unofficial community project. It is not affiliated with, endorsed by, or maintained by Amazon Web Services (AWS), Amazon CloudWatch, or the OpenTelemetry project.

Why This Exporter?

OpenTelemetry and AWS support CloudWatch EMF primarily through Collector or CloudWatch Agent workflows. This package covers the collectorless Python SDK use case: emit valid CloudWatch EMF JSON directly from a Python metrics exporter and let Lambda, ECS/Fargate, or EC2 log collection deliver it to CloudWatch Logs.

Approach	Runtime Model	Operational Fit
ADOT Collector	Separate collector process	Full collector pipeline and AWS-managed integration
ADOT Lambda Layer	Embedded collector layer	Lambda workloads that need Collector features
This Exporter	In-process Python SDK exporter	Collectorless workloads that emit EMF through stdout or logs

Installation

pip install opentelemetry-exporter-cloudwatch-emf

To install a specific source release from GitHub:

pip install git+ssh://[e-mail]/darrenhaas/cw-emf-exporter.git@v0.2.4

Quick Start

from opentelemetry import metrics
from opentelemetry.sdk.metrics import MeterProvider
from opentelemetry.sdk.metrics.export import PeriodicExportingMetricReader
from opentelemetry_exporter_cloudwatch_emf import CloudWatchEMFExporter

# Create exporter
exporter = CloudWatchEMFExporter(namespace="MyApplication")

# Set up meter provider
reader = PeriodicExportingMetricReader(exporter, export_interval_millis=60000)
provider = MeterProvider(metric_readers=[reader])
metrics.set_meter_provider(provider)

# Create and use metrics
meter = metrics.get_meter("my-service")
counter = meter.create_counter("requests", unit="1")
counter.add(1, {"endpoint": "/api/users", "method": "GET"})

The exporter writes one EMF JSON document per metric batch to the configured output stream. By default, that stream is sys.stdout.

Documentation

Document	Description
Architecture	System design, data flow, components
Configuration	All options with examples
API Reference	Public API and helper behavior
Examples	Usage patterns and recipes
Release Process	PyPI release checklist
Changelog	Release history
Project Notice	Unofficial project and trademark notice
Community Gap	Upstream context for collectorless Python EMF export

Features

Metric Types Support

OTel Metric Type	EMF Output	Percentile Support
Counter	Single value	N/A
Gauge	Single value	N/A
Histogram	Values array	Yes (p50, p99, etc.)
ExponentialHistogram	Values array	Yes (p50, p99, etc.)

AWS Environment Auto-Detection

When auto_detect_aws=True, the exporter adds stable AWS environment dimensions when it can detect them.

Environment	Detection Signal	Added Dimensions
Lambda	AWS_LAMBDA_FUNCTION_NAME	Function name, version, region, memory size
ECS/Fargate	ECS_CONTAINER_METADATA_URI	ECS marker, region, selected task metadata
EC2/generic AWS	AWS_REGION	Region

Unit Mapping

OpenTelemetry (UCUM)	CloudWatch Unit
s	Seconds
ms	Milliseconds
us	Microseconds
By	Bytes
KiBy	Kilobytes
MiBy	Megabytes
GiBy	Gigabytes
TiBy	Terabytes
By/s	Bytes/Second
1, {request}, {error}	Count
%	Percent

Configuration Summary

CloudWatchEMFExporter(
    # Required
    namespace="MyApp",              # CloudWatch namespace (1-256 chars)

    # Output
    output=sys.stdout,              # Where to write EMF JSON

    # Dimensions
    dimension_keys=["svc", "env"],  # Filter dimensions (None = all)
    max_dimensions=30,              # Max dimensions (CloudWatch limit: 30)

    # Resolution
    storage_resolution=60,          # 1 = high-res, 60 = standard

    # Log Routing (for CloudWatch Agent)
    log_group_name="/aws/myapp",    # Target log group
    log_stream_name="stream-1",     # Target log stream

    # Features
    auto_detect_aws=True,           # Auto-detect Lambda/ECS/EC2
    histogram_as_values=True,       # Enable percentile calculations

    # Advanced
    timestamp_fn=lambda: int(time.time() * 1000),  # Custom timestamp
)

EMF Output Format

{
  "_aws": {
    "Timestamp": 1700000000000,
    "CloudWatchMetrics": [{
      "Namespace": "MyApplication",
      "Dimensions": [["service", "endpoint"]],
      "Metrics": [{
        "Name": "request_latency",
        "Unit": "Milliseconds",
        "StorageResolution": 60
      }]
    }]
  },
  "request_latency": [5, 5, 15, 15, 15],
  "service": "api",
  "endpoint": "/users"
}

Histogram values use bucket representatives repeated by bucket count. Large histograms are proportionally sampled to fit EMF's 100-value numeric array limit.

Development

# Install dev dependencies
uv sync --extra dev

# Run tests
uv run pytest

# Lint, type check, and package validation
uv run flake8 src tests
uv run mypy src
uv run black --check src tests
uv build
uv run twine check dist/*

License

Apache 2.0 - See LICENSE