dbBus
Simple async messaging framework with database as transport layer.
DotNet Core 2.2
DotNet Standard 2.0
Currently supported:
- DI
- Ninject
- Microsoft.Extensions.DependencyInjection;
- Databases:
- Mssql
- Sqlite
- Sqlite in memory (awesome for unit testing)
Usage
Console application
var bus = Bus.Configure()
.UseNinject(kernel)
.UseDefaultConsoleLogger()
.UseMssql("Server=<addr>;Database=<database>;User Id=<user>;Password=<password>;MultipleActiveResultSets=true;"))
.RegisterHandler<MyMessageHandler>()
.Build();
bus.Start();AspNet Core application
Add this to Startup.cs
public void ConfigureServices(IServiceCollection services)
{
...
services.AddDbBus(() => Bus.Configure()
.UseAspNetCore(services)
.UseMssql("connection string goes here")
.RegisterHandler<MyMessageHandler>());
...
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
...
app.UseDbBus();
...
}In case of Mssql, is important to set MultipleActiveResultSets in connection string.
Create message class:
public class MyMessage : IMessage
{
public long InternalId { get; set; } // derived
// your properties here
}Create handler class:
public class MyMessageHandler : IHandle<MyMessage>
{
public async Task Handle(MyMessage message)
{
// process message here
}
}Sending messages
You can just simply use your bus instance:
await bus.Publish(new MyMessage());... or you can use bus via constructor dependency injection:
public class MyAwesomeClass
{
private readonly IBus bus;
public MyAwesomeClass(IBus bus)
{
this.bus = bus;
}
public async Task MyMethod()
{
await this.bus.Publish(new MyMessage());
}
}Custom error handler
Create class that implements IErrorHandler
public class MyErrorHandler : IErrorHandler
{
public async Task<bool> OnError(object sender, Exception e, IMessage message, int retryNo)
{
Console.WriteLine($"Error reading message #{message.InternalId}, retry #{retryNo}");
return await Task.FromResult(true); // true if you like to retry message handling
}
}.. and register during bus configuration:
var bus = Bus.Configure()
.UseNinject(kernel)
.UseMssql("my onnection string"))
.RegisterHandler<MyMessageHandler1>()
.RegisterErrorHandler<MyErrorHandler>() <-- custom error handler
.Build();Configuration parameters
| Parameter | Description | Default value |
|---|---|---|
| PullInterval | delay between each message pull | 1000 ms |
| PullMaxMessages | max number of processed message in each pull | 100 |
| MaxRetry | how many times engine will retry handling message | 3 times |
| MessageLifetime | how long message will be available for pulling | 7 days |
