PollyDapper

Polly v8 resilience pipelines for Dapper — wrap QueryAsync, ExecuteAsync, and other Dapper calls with retry, timeout, circuit-breaker, and more using a single ResilientDbConnection decorator. Zero changes to your SQL.

var resilient = connection.WithPolly(pipeline =>
    pipeline
        .AddRetry(new RetryStrategyOptions
        {
            MaxRetryAttempts = 3,
            Delay = TimeSpan.FromMilliseconds(200),
            ShouldHandle = new PredicateBuilder().Handle<Exception>(),
        })
        .AddTimeout(TimeSpan.FromSeconds(5)));

var orders = await resilient.QueryAsync<Order>("SELECT * FROM Orders WHERE CustomerId = @Id", new { Id = id });

Every Dapper call is now automatically wrapped with retry + timeout — zero changes to existing SQL.

---

Why PollyDapper?

Dapper is intentionally minimal — it gives you no interception point for cross-cutting concerns like retry or timeout. PollyDapper adds that layer cleanly.

Without PollyDapper	With PollyDapper
Write try/catch + retry loops around every query	One WithPolly(...) call
Manually pass CancellationToken for timeouts	Timeout managed by the pipeline
Duplicate retry logic across repositories	Single pipeline applied everywhere
Must touch every query to add resilience	Zero changes to existing SQL

---

Installation

dotnet add package PollyDapper

Targets net6.0, net8.0, and net9.0.

Dependencies: Polly.Core 8.*, Dapper 2.*, Microsoft.Extensions.DependencyInjection.Abstractions 8.*

---

Quick start

1. Inline pipeline (ad-hoc usage)

using PollyDapper;

var resilient = connection.WithPolly(pipeline =>
    pipeline.AddRetry(new RetryStrategyOptions
    {
        MaxRetryAttempts = 3,
        Delay = TimeSpan.FromMilliseconds(200),
        BackoffType = DelayBackoffType.Exponential,
        ShouldHandle = new PredicateBuilder().Handle<Exception>(),
    }));

var users = await resilient.QueryAsync<User>("SELECT * FROM Users");

2. Pre-built pipeline

var pipeline = new ResiliencePipelineBuilder()
    .AddRetry(new RetryStrategyOptions { MaxRetryAttempts = 3 })
    .AddTimeout(TimeSpan.FromSeconds(10))
    .Build();

var resilient = connection.WithPolly(pipeline);
var count = await resilient.ExecuteScalarAsync<int>("SELECT COUNT(*) FROM Orders");

3. Dependency injection

// Program.cs
builder.Services.AddPollyDapper(pipeline =>
    pipeline
        .AddRetry(new RetryStrategyOptions { MaxRetryAttempts = 3 })
        .AddTimeout(TimeSpan.FromSeconds(5)));

// Repository
public class OrderRepository(IDbConnection db, ResiliencePipeline pipeline)
{
    public Task<IEnumerable<Order>> GetAllAsync() =>
        db.WithPolly(pipeline).QueryAsync<Order>("SELECT * FROM Orders");

    public Task<int> InsertAsync(Order order) =>
        db.WithPolly(pipeline).ExecuteAsync(
            "INSERT INTO Orders (CustomerId, Total) VALUES (@CustomerId, @Total)", order);
}

---

Supported methods

Method	Description
QueryAsync<T>	Returns IEnumerable<T>
QueryFirstAsync<T>	First row, throws if empty
QueryFirstOrDefaultAsync<T>	First row or default
QuerySingleAsync<T>	Exactly one row, throws otherwise
QuerySingleOrDefaultAsync<T>	One row or default
ExecuteAsync	Rows affected
ExecuteScalarAsync<T>	First column of first row

---

Pipeline order

Polly strategies are applied outer-to-inner (left-to-right). The recommended order is:

[Timeout] → [Retry] → [Circuit Breaker] → [Dapper]

pipeline
    .AddTimeout(TimeSpan.FromSeconds(10))    // 1. Overall deadline
    .AddRetry(retryOptions)                  // 2. Retry on failure
    .AddCircuitBreaker(cbOptions)            // 3. Open circuit if overloaded

---

ASP.NET Core example

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddScoped<IDbConnection>(_ =>
    new SqlConnection(builder.Configuration.GetConnectionString("Default")));

builder.Services.AddPollyDapper(pipeline =>
    pipeline
        .AddRetry(new RetryStrategyOptions
        {
            MaxRetryAttempts = 3,
            Delay = TimeSpan.FromMilliseconds(100),
            BackoffType = DelayBackoffType.Exponential,
            ShouldHandle = new PredicateBuilder()
                .Handle<SqlException>(ex => ex.IsTransient),
        })
        .AddTimeout(TimeSpan.FromSeconds(30))
        .AddCircuitBreaker(new CircuitBreakerStrategyOptions
        {
            FailureRatio = 0.5,
            MinimumThroughput = 10,
            SamplingDuration = TimeSpan.FromSeconds(30),
            BreakDuration = TimeSpan.FromSeconds(15),
        }));

---

Related Packages

Package	Downloads	Description
PollyHealthChecks		ASP.NET Core health checks for Polly v8 circuit breakers — expose circuit-breaker state (Closed, HalfOpen, Open, Isolated) as /health endpoint responses
PollyBackoff		Backoff delay strategies for Polly v8 resilience pipelines
PollyEFCore		Polly v8 resilience pipelines for Entity Framework Core — wrap every EF Core query and SaveChanges with retry, timeout and circuit-breaker via a single AddPollyResilience() call
PollyMailKit		Polly v8 resilience pipelines for MailKit — retry, timeout, and circuit-breaker for SmtpClient.SendAsync and any MailKit SMTP operation
PollyMassTransit		Polly v8 resilience pipelines for MassTransit — retry, timeout, and circuit-breaker for IBus.Publish and ISendEndpointProvider.Send
PollyAzureEventHub		Polly v8 resilience pipelines for Azure Event Hubs — retry, timeout, and circuit-breaker for EventHubProducerClient and EventHubConsumerClient
PollyOpenAI		Polly v8 resilience for OpenAI and Azure OpenAI API calls
PollySignalR		Polly v8 reconnect policy for SignalR
PollyElasticsearch		Polly v8 resilience pipelines for Elastic.Clients.Elasticsearch 8+ — retry, timeout, and circuit-breaker for any Elasticsearch operation, plus a built-in ElasticTransientErrors predicate covering rate limiting (429), service unavailability (503), gateway timeouts (504), and connection failures
PollyHangfire		Polly v8 resilience pipelines for Hangfire — retry, timeout, and circuit-breaker for IBackgroundJobClient.Enqueue and Schedule
PollySendGrid		Polly v8 resilience pipelines for SendGrid — retry, timeout, and circuit-breaker for ISendGridClient.SendEmailAsync
PollyMediatR		Polly v8 resilience pipelines for MediatR — add retry, timeout, circuit-breaker, rate-limiting, hedging, and chaos engineering to any MediatR request handler with a single line of DI registration
PollyAzureKeyVault		Polly v8 resilience pipelines for Azure Key Vault — retry, timeout, and circuit-breaker for SecretClient, KeyClient, and CertificateClient
PollyAzureQueueStorage		Polly v8 resilience pipelines for Azure Queue Storage — retry, timeout, and circuit-breaker for Azure.Storage.Queues QueueClient
PollySqlClient		Polly v8 resilience pipelines for Microsoft.Data.SqlClient (SQL Server and Azure SQL) — retry, timeout, and circuit-breaker for SqlConnection queries and commands, plus a built-in SqlServerTransientErrors predicate covering all common SQL Server and Azure SQL transient error numbers
PollyRedis		Polly v8 resilience for StackExchange.Redis
PollyAzureTableStorage		Polly v8 resilience pipelines for Azure Table Storage — retry, timeout, and circuit-breaker for Azure.Data.Tables TableClient
PollyChaos		Chaos engineering and fault-injection resilience strategies for Polly v8 pipelines

💼 Need .NET consulting?

The author of this package is available for consulting on Polly v8 resilience, Azure cloud architecture, and clean .NET design.

→ solidqualitysolutions.com · LinkedIn

License

MIT