DotEventOutbox 1.0.4

DotEventOutbox

Overview

DotEventOutbox is a .NET library designed to streamline the implementation of the outbox pattern with MediatR and Entity Framework. It ensures reliable, consistent, and idempotent processing of domain events.

Features

• MediatR and Entity Framework Integration: Seamless interaction for managing and dispatching domain events.
• Idempotent Processing: Ensures each event is processed only once, avoiding duplicate handling.
• Automated Outbox Message Management: Handles conversion and lifecycle of domain events as outbox messages.
• Dead Letter Queue: Manages failed messages for later analysis or reprocessing.
• Quartz Integration: Automates and schedules outbox message processing.
• Configurable Settings: Customizable behavior through EventOutboxSettings.

Installing DotEventOutbox

You should install DotEventOutbox with NuGet:

Install-Package DotEventOutbox

Or via the .NET Core command line interface:

dotnet add package DotEventOutbox

Either commands, from Package Manager Console or .NET Core CLI, will download and install DotEventOutbox and all required dependencies.

Using Contracts-Only Package

To reference only the contracts for DotEventOutbox, which includes:

• IEvent
• DomainEvent
• IDomainEventEmitter

Add a package reference to DotEventOutbox.Contracts

This package is useful in scenarios where your DotEventOutbox contracts are in a separate assembly/project from handlers.

Registering with IServiceCollection

DotEventOutbox supports Microsoft.Extensions.DependencyInjection.Abstractions directly. To register various DotEventOutbox services:

services.AddDotEventOutbox(configuration,
  options => options.UseNpgsql(configuration.GetConnectionString("AppDb")));

Configuration

Detail the available settings in DotEventOutbox and their impact:

• ProcessingIntervalInSeconds: Defines the frequency of outbox processing cycles.
• MaxMessagesProcessedPerBatch: Limits the number of messages processed in a single batch to optimize performance.
• RetryIntervalInMilliseconds: Specifies the delay between retry attempts for failed message processing.
• MaxRetryAttempts: Sets the maximum number of retries for each message before moving it to the dead-letter queue.

// appsettings.json
{
  "ConnectionStrings": {
    "AppDb": "Your-Database-Connection-String"
  },
  "DotEventOutbox": {
    "ProcessingIntervalInSeconds": 10,
    "MaxMessagesProcessedPerBatch": 10,
    "RetryIntervalInMilliseconds": 50,
    "MaxRetryAttempts": 3
  }
}

Example Usage

Below is an example demonstrating how to use DotEventOutbox in a console application:

// Program.cs
var user = new User(Guid.NewGuid(), "John Doe", "John.Doe@Demo.com");
dbContext.Users.Add(user);
var outboxCommitProcessor = scope.ServiceProvider.GetRequiredService<IOutboxCommitProcessor>();
await outboxCommitProcessor.ProcessAndSaveAsync(dbContext);

Contributing

We welcome contributions and suggestions! Please read through our contributing guidelines for more information on how to get started.

License

This project is licensed under the MIT License.