DotEventOutbox 1.1.4

DotEventOutbox

Overview

DotEventOutbox is a .NET library created to enhance the implementation of the outbox pattern, integrating seamlessly with MediatR and Entity Framework. This library is key in ensuring that domain events are processed in a reliable, consistent, and idempotent manner.

Key Features

• Seamless Integration with MediatR and Entity Framework: DotEventOutbox provides an effortless and smooth integration for managing and dispatching domain events using MediatR and Entity Framework.
• Idempotent Processing: Guarantees that each event is processed exactly once, thereby preventing any possibility of duplicate event handling.
• Advanced Outbox Message Management: Automates the conversion, storage, and lifecycle management of domain events into outbox messages.
• Robust Dead Letter Queue: Implements a system to manage failed messages, allowing for their later analysis or reprocessing.
• Quartz Integration: Provides an automated and scheduled approach to outbox message processing using Quartz.
• Configurable Settings: Offers a wide range of customizable settings through EventOutboxSettings to tailor the outbox behavior to your specific needs.

Installation

Install DotEventOutbox via NuGet:

Install-Package DotEventOutbox

Or through the .NET Core CLI:

dotnet add package DotEventOutbox

Both commands will download and install DotEventOutbox along with all necessary dependencies.

Contracts-Only Package

For projects needing only the contracts of DotEventOutbox, such as IEvent, DomainEvent, and IDomainEventEmitter, use the DotEventOutbox.Contracts package:

dotnet add package DotEventOutbox.Contracts

This is ideal for separating DotEventOutbox contracts from their handlers in different assemblies or projects.

Service Registration

Register DotEventOutbox services easily with IServiceCollection:

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

Database Migration

Create necessary tables by executing:

await app.MigrateDotEventOutbox();

This will create OutboxMessages, OutboxMessageConsumers, and DeadLetterMessages tables.

Configuration Details

Customize DotEventOutbox using these settings:

• ProcessingIntervalInSeconds: Time interval for processing outbox messages.
• MaxMessagesProcessedPerBatch: Maximum number of messages processed per batch.
• RetryIntervalInMilliseconds: Time delay between retry attempts for failed messages.
• MaxRetryAttempts: Maximum retry attempts before moving a message to the dead-letter queue.

Example appsettings.json:

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

Example Usage

Here's a basic example in a console application:

// Program.cs
// Create a new user instance
var user = new User(Guid.NewGuid(), "John Doe", "John.Doe@Demo.com");

// Raise the UserCreatedDomainEvent
user.RaiseEvent(new UserCreatedDomainEvent(user.Name, user.Email));

// Add the new user to the DbContext
dbContext.Users.Add(user);

// Save changes and process domain events using OutboxCommitProcessor
var outboxCommitProcessor = scope.ServiceProvider.GetRequiredService<IOutboxCommitProcessor>();
await outboxCommitProcessor.ProcessAndSaveAsync(dbContext);

For a comprehensive example, visit the Demo Repository.

Contributing

Contributions and suggestions are highly appreciated. Please review our Contributing Guidelines for detailed information on how to participate.

License

DotEventOutbox is open-sourced under the MIT License.