Tolitech.Infrastructure.Messaging.EntityFrameworkCore 1.0.0-preview.4

Tolitech.Infrastructure.Messaging.EntityFrameworkCore

A .NET library that implements the Outbox Pattern for reliable integration event publishing using Entity Framework Core. It provides an OutboxMessage entity and configuration utilities to persist and manage integration events, ensuring consistency between your database and message broker.

Features

• Outbox Pattern implementation for integration events
• Entity and configuration for storing events in the database
• Seamless integration with Entity Framework Core
• Support for delayed and scheduled event processing
• Retry and error tracking for event delivery

Installation

Add the NuGet package to your project:

dotnet add package Tolitech.Infrastructure.Messaging.EntityFrameworkCore

Getting Started

1. Add the OutboxMessage Entity to Your DbContext

In your DbContext, add a DbSet<OutboxMessage>:

using Tolitech.Infrastructure.Messaging.EntityFrameworkCore.Entities;

public class MyDbContext : DbContext
{
    public DbSet<OutboxMessage> OutboxMessages { get; set; }
    // ... other DbSets
}

2. Configure the OutboxMessage Entity

In your OnModelCreating method, apply the configuration:

using Tolitech.Infrastructure.Messaging.EntityFrameworkCore.Configurations;

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.ApplyConfiguration(new OutboxMessageConfiguration("OutboxMessages"));
    base.OnModelCreating(modelBuilder);
}

3. Register and Save Integration Events

Use the Outbox class to register integration events and persist them as OutboxMessage entities:

using Tolitech.Infrastructure.Messaging;
using Tolitech.Infrastructure.Messaging.EntityFrameworkCore.Entities;

// Register events
var outbox = new Outbox();
outbox.RegisterIntegrationEvent(new MyIntegrationEvent());

// Save to database
foreach (var envelope in outbox.GetIntegrationEventEnvelopes())
{
    var outboxMessage = OutboxMessage.From(envelope);
    dbContext.OutboxMessages.Add(outboxMessage);
}
await dbContext.SaveChangesAsync();

4. Processing Outbox Messages

Implement a background service or scheduled job to read, publish, and update the status of OutboxMessage records:

var pendingMessages = await dbContext.OutboxMessages
    .Where(m => !m.IsProcessed && !m.IsProcessing)
    .ToListAsync();

foreach (var message in pendingMessages)
{
    message.MarkAsProcessing();
    // Publish event to message broker
    // ...
    message.MarkAsSucceeded(); // or message.MarkAsFailed(error)
}
await dbContext.SaveChangesAsync();

Advanced

• Supports delayed and scheduled event processing via ProcessingDelayTicks and EnqueueDateUtc.
• Retry logic and error tracking are built-in.
• Use indexes for efficient querying of pending messages.

Tolitech.Infrastructure.Messaging.EntityFrameworkCore enables reliable, consistent, and scalable event-driven architectures with .NET and EF Core.