Polly.Redis

Distributed Circuit Breaker for .NET - Simple, Configurable, Production-Ready

🚀 Quick Start

Install

dotnet add package Polly.Redis

Simplest Usage (2 lines!)

using Polly.Redis;

// Create
var cb = CircuitBreaker.Create("my-api", "localhost:6379");

// Use
var result = await cb.Execute(async () => await CallExternalApi());

That's it! All instances sharing the same circuit ID coordinate automatically.

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📖 Usage Examples

Example 1: Basic Protection

var cb = CircuitBreaker.Create("payment-api", "redis:6379");

try
{
    var result = await cb.Execute(async () => await PaymentService.Charge(100));
}
catch (CircuitOpenException ex)
{
    // Service is unhealthy, circuit is open
    Console.WriteLine($"Service down. Retry after: {ex.RetryAfter}");
}

Example 2: Automatic Fallback

var cb = CircuitBreaker.Create("weather-api", "redis:6379");

// Tries primary, uses fallback if circuit is open
var weather = await cb.Execute(
    action: async () => await FastWeatherApi.Get(),
    fallback: async () => await SlowButStableApi.Get()
);

Example 3: Custom Configuration

var cb = CircuitBreaker.Create(config => config
    .WithRedis("your-redis:6379")
    .WithCircuitId("inventory-service")
    .FailWhen(failureRatio: 0.3, minimumCalls: 10)  // Break at 30% failure
    .StayOpenFor(seconds: 60)                        // Stay open for 1 minute
    .MeasureFailuresOver(TimeSpan.FromSeconds(30))   // 30s sliding window
    .OnStateChange(change => 
    {
        Console.WriteLine($"Circuit {change.CircuitId} is now {change.NewState}");
        // Send alert, update dashboard, etc.
    })
);

Example 4: Dependency Injection

// Program.cs
builder.Services.AddCircuitBreaker("payment-api", config => config
    .WithRedis(builder.Configuration.GetConnectionString("Redis"))
    .FailWhen(failureRatio: 0.5, minimumCalls: 5)
    .StayOpenFor(seconds: 30)
);

// In your service
public class PaymentService
{
    private readonly ICircuitBreaker _cb;
    
    public PaymentService([FromKeyedServices("payment-api")] ICircuitBreaker cb)
    {
        _cb = cb;
    }
    
    public async Task<Receipt> ProcessPayment(decimal amount)
    {
        return await _cb.Execute(async () => 
        {
            return await externalPaymentGateway.Charge(amount);
        });
    }
}