Franz.Common.Mediator.Polly 1.5.9

Franz.Common.Mediator.Polly

Franz.Common.Mediator.Polly extends Franz.Common.Mediator with Polly-based resilience pipelines. It gives you retry, circuit breaker, timeout, bulkhead isolation, and advanced circuit breaker for Mediator requests � all with enriched Serilog logging built-in.

No extra wiring. No extra boilerplate. Just plug and go.

• Current Version: 1.5.9

? Features

• ?? Retry Pipeline: automatic retries with backoff.

• ? Circuit Breaker Pipeline: stop flooding failing dependencies.

• ?? Advanced Circuit Breaker Pipeline: trip based on failure rate in a rolling window.

• ?? Timeout Pipeline: abort long-running requests.

• ?? Bulkhead Pipeline: limit concurrent executions.

• ?? Enriched Logging: every pipeline execution logs:

  • Correlation ID
  • Request type
  • Policy name
  • Pipeline name
  • Success/failure status
  • Execution time

Logs are pushed into Serilog with all the contextual properties you already get from SerilogLoggingPipeline.

?? Installation

dotnet add package Franz.Common.Mediator.Polly

?? Setup

1. Centralized Policy Registration

Instead of scattering PolicyRegistry.Add(...) calls, use AddFranzPollyPolicies() to declare everything in one place:

using Polly;
using Franz.Common.Mediator.Polly.Extensions;

builder.Services.AddFranzPollyPolicies(options =>
{
    // ?? Retry policy with exponential backoff
    options.Policies["DefaultRetry"] = Policy
        .Handle<Exception>()
        .WaitAndRetryAsync(
            retryCount: 3,
            sleepDurationProvider: attempt => TimeSpan.FromSeconds(Math.Pow(2, attempt))
        );

    // ?? Circuit breaker (basic)
    options.Policies["DefaultCircuitBreaker"] = Policy
        .Handle<Exception>()
        .CircuitBreakerAsync(
            exceptionsAllowedBeforeBreaking: 2,
            durationOfBreak: TimeSpan.FromSeconds(30)
        );

    // ?? Advanced circuit breaker (failure rate over time)
    options.Policies["DefaultAdvancedBreaker"] = Policy
        .Handle<Exception>()
        .AdvancedCircuitBreakerAsync(
            failureThreshold: 0.5,                // trip if 50% fail
            samplingDuration: TimeSpan.FromSeconds(30),
            minimumThroughput: 8,                 // at least 8 calls in window
            durationOfBreak: TimeSpan.FromSeconds(15)
        );

    // ? Timeout policy
    options.Policies["DefaultTimeout"] = Policy
        .TimeoutAsync(TimeSpan.FromSeconds(5));

    // ?? Bulkhead isolation
    options.Policies["DefaultBulkhead"] = Policy
        .BulkheadAsync(
            maxParallelization: 10,
            maxQueuingActions: 20
        );
});

2. Register Mediator + Pipelines

Now wire policies into pipelines by name � the Franz way:

using Franz.Common.Mediator.Extensions;
using Franz.Common.Mediator.Polly.Extensions;

builder.Services
    .AddFranzMediator(typeof(Program).Assembly)
    .AddFranzRetryPipeline("DefaultRetry")
    .AddFranzCircuitBreakerPipeline("DefaultCircuitBreaker")
    .AddFranzAdvancedCircuitBreakerPipeline("DefaultAdvancedBreaker")
    .AddFranzTimeoutPipeline("DefaultTimeout")
    .AddFranzBulkheadPipeline("DefaultBulkhead");

That�s it. One registry + one mapping = full resilience layer with enriched logging.

3. Example Logs (Serilog)

When a request runs successfully:

?? Handling GetBookQuery [correlationId=abc123] with policy DefaultRetry
? GetBookQuery [correlationId=abc123] completed in 54ms (policy DefaultRetry)

If retries fail and the circuit breaker opens:

? GetBookQuery [correlationId=abc123] failed after 3 retries (policy DefaultRetry)
? Circuit opened for 30s (policy DefaultCircuitBreaker)

If a timeout is triggered:

?? GetBookQuery [correlationId=abc123] timed out after 5s (policy DefaultTimeout)

?? Pipelines Overview

Each pipeline resolves its named policy from the IReadOnlyPolicyRegistry<string> you configure.

? Benefits

• Centralized resilience policy registration.
• Opt-in: only register the pipelines you need.
• Zero boilerplate: enriched logging comes out-of-the-box.
• Structured observability: Serilog correlation IDs across retries, timeouts, and circuit breakers.
• Enterprise-ready: clean DI, config-driven, consistent patterns.

?? Roadmap

• Policy composition helpers (chaining retry + circuit breaker).
• Prebuilt default policy sets for common scenarios.

?? With Franz.Common.Mediator.Polly, using Polly inside Mediator is frictionless: resilience + structured logs, with just two extension calls.

Changelog

version 1.4.4

• Corrected Polly policy registry to use generic IAsyncPolicy<HttpResponseMessage>, avoiding invalid cast exceptions
• Ensured pipeline registrations handle generic types cleanly