EventBus

Branch	Pipeline
master
release
milestone/1.0.0

OverView

EventBus is a .Net Standard library to achieve eventually consistent in distributed architectures system like SOA,MicroService. It is lightweight,easy to use and efficiently.

Getting Started

Step 1 : Configure EventBus Options

*** Add following code after services.AddDbContext in StartUp.cs ***

services.AddEventBus(options =>
{
  // using EntityFramework
  options.UseEntityframework<**Your DbContext Type**>();
  
  // OR using Ado.NET 
  options.UseMySQL(**Database connection string**)
  
  // using RabbitMQ
  options.UseRabbitMQ(rabbit =>
  {
    rabbit.HostName = "**Your hostname of RabbitMQ**";
    rabbit.UserName = "**Your username if needed**";
    rabbit.Password = "**Your password if needed**";
  });
 });

*** Add following codes in Configure scope of StartUp.cs ***

app.UseEventBus();

Step 2 : Publish Event

• Inject IEventPublisher in constructor like .ctor(IEventPublisher eventPublisher)
• Begin a transaction
  • using EntityFramework

using(var transaction = dbContext.Database.BeginTransaction)
{
  //TODO:Businesses codes
  
  //Publish Event
  await _eventPublisher.PrepareAsync(/*RouteKey*/, /*Content Object*/, /*MetaData Object*/);
  
  //Commit transaction
  transaction.Commit();
  
  //Confirm Published Event.The event message won't publish untill invoked **IEventPublisher.ConfirmAsync()**
  //And you can decide when the event message be confirmed all by your self.
  await _eventPublisher.ConfirmAsync();
  
  //Or you can just rollback these messages when exception was thrown.
  await _eventPublisher.RollbackAsync();
}

• using Ado.NET

 IDbConnection dbConnection; /*Open your database connection.*/
IDbTransaction dbTransaction = dbConnection.BeginTransaction();

//TODO:Businesses codes

//Publish Event
await _eventPublisher.PrepareAsync(/*RouteKey*/, /*Content Object*/, /*MetaData Object*/,dbConnection,dbTransaction);

//Commit transaction
dbTransaction.Commit();
dbConnection.Close();

//Confirm Published Event.The event message won't publish untill invoked **IEventPublisher.ConfirmAsync()**
//And you can decide when the event message should be confirmed all by your self.
await _eventPublisher.ConfirmAsync();

//Or you can just rollback these messages when exception was thrown.
await _eventPublisher.RollbackAsync();

step 3 : Dead letter callback handler

• Declare a callback handler class implemented IFailureHandler
• Register callback handle in AddEventBus scope

options.UseFailureHandle(failure =>
{
 failure.RegisterFailureCallback(/*RouteKey*/, /*Type of your deadletter callback handler*/);
});

Step 4 : Consumer callback handler

• Declare a callback handler class implemented ISubscribeCallbackHandler
• Register callback handle in StartUp.cs

services.AddSub(options =>
{
  options.ConsumerClientCount = 1;
  options.DefaultGroup = "/*Default Group Name*/";
  // Use default group
  options.RegisterCallback(/*RouteKey*/, /*Type of your callback handler*/);
  // Use specialized group
  options.RegisterCallback(/*RouteKey*/,/*Group Name*/ /*Type of your callback handler*/);
 });