PollyOpenTelemetry 1.0.5

PollyOpenTelemetry

<img src="icon.png" width="100" align="right" />

OpenTelemetry instrumentation for Polly v8 resilience pipelines.

Emits distributed trace spans (Activity) and metrics for retry, circuit breaker, and timeout strategies — giving you full observability into your resilience layer.

Polly ships built-in logging and basic metrics via ConfigureTelemetry(ILoggerFactory).
This package adds the missing piece: OpenTelemetry-native traces and enriched metrics.

Installation

dotnet add package PollyOpenTelemetry

Quick Start

1. Register with the OpenTelemetry SDK

services.AddOpenTelemetry()
    .WithTracing(tracing => tracing
        .AddPollyInstrumentation()          // register the "Polly" ActivitySource
        .AddOtlpExporter())
    .WithMetrics(metrics => metrics
        .AddPollyInstrumentation()          // register the "Polly" Meter
        .AddOtlpExporter());

2. Add to your resilience pipeline

var pipeline = new ResiliencePipelineBuilder()
    .AddPollyOpenTelemetry()                // ← one call enables both traces + metrics
    .AddRetry(new RetryStrategyOptions
    {
        MaxRetryAttempts = 3,
        BackoffType = DelayBackoffType.Exponential,
    })
    .AddCircuitBreaker(new CircuitBreakerStrategyOptions
    {
        FailureRatio = 0.5,
        MinimumThroughput = 10,
    })
    .AddTimeout(TimeSpan.FromSeconds(30))
    .Build();

With Dependency Injection

services.AddResiliencePipeline("my-http-client", builder =>
{
    builder
        .AddPollyOpenTelemetry()
        .AddRetry(new RetryStrategyOptions { MaxRetryAttempts = 3 })
        .AddTimeout(TimeSpan.FromSeconds(30));
});

Emitted Telemetry

Activities (Traces)

Common Activity Tags

Additional Tags per Activity

polly.attempt: polly.attempt.number, polly.attempt.handled
polly.retry: polly.attempt.number, polly.retry.delay_ms
polly.circuit_breaker.opened: polly.circuit_breaker.break_duration_ms, polly.circuit_breaker.is_manual
polly.timeout: polly.timeout_ms

Metrics

Options

builder.AddPollyOpenTelemetry(options =>
{
    options.EnableTracing = true;   // default: true
    options.EnableMetrics = true;   // default: true

    // Enrich activities with custom tags
    options.EnrichActivity = (activity, resilienceEvent, source) =>
    {
        activity.SetTag("my.custom.tag", "value");
    };
});

Composing with Polly's Built-in Logging

AddPollyOpenTelemetry() is safe to combine with Polly's built-in ConfigureTelemetry(ILoggerFactory) — both listeners are composed automatically:

var pipeline = new ResiliencePipelineBuilder()
    .ConfigureTelemetry(loggerFactory)    // Polly structured logging + basic metrics
    .AddPollyOpenTelemetry()              // OpenTelemetry traces + enriched metrics
    .AddRetry(...)
    .Build();

Sample Trace Output

▶ polly.attempt   [polly.pipeline.name=payment-api] [polly.attempt.number=0] [polly.outcome=failure]
  ✗ error.type=System.Net.Http.HttpRequestException
▶ polly.retry     [polly.retry.delay_ms=200] [polly.attempt.number=0]
▶ polly.attempt   [polly.pipeline.name=payment-api] [polly.attempt.number=1] [polly.outcome=success]

Requirements

• .NET 8.0+
• Polly 8.x
• OpenTelemetry 1.x

Publishing

This package is published to NuGet.org via GitHub Actions using NuGet trusted publishing — no API key secret is stored in the repository.

Setup (one-time)

1. On nuget.org, go to your package → Manage → Trusted Publishers → Add a publisher
2. Choose GitHub Actions and enter:
   • Owner: Sweevo
   • Repository: Polly-Contrib-OpenTelemetry
   • Workflow: build.yml
3. Push a v* tag to trigger the publish workflow:

   git tag v1.0.0
   git push --tags
   

The workflow requests a short-lived OIDC token from GitHub (audience api.nuget.org) and uses it as the push credential — no NUGET_API_KEY secret required.

License

MIT — Copyright © 2025 Justin Bannister