NServiceBus.Problem

Introduction

Simple client/server application.

The client sends EventA to the server. In EventA there is a CorrelationId set.

In the server when it receives EventA it starts a saga and sets CorrelationId in saga data. CorrelationId is marked with [Unique].

When EventA is received it creates an EventB and sets the CorrelationId on EventB to the one received from EventA. After that it publishes EventB.

When EventB is received in the saga. It creates an EventC and sets the CorrelationId and publishes it. Last when EventC is received the saga is marked complete.

Setup

1. Set startup projects in solution to Client (console application) Server (nservicebus host)

2. Make sure server is set to start nservicebus.host.exe in properties/debug

3. Run solution (don't debug)

4. From the client, just press any key except 'q' to send a message to the server

5. Server should receive EventA, publish EventB, receive EventB, publish EventC, Receive EventC and mark as complete.

After a few times this exception is thrown:

2012-10-12 20:44:08,214 [Worker.14] WARN NServiceBus.Unicast.Transport.Transact ional.TransactionalTransport [(null)] <(null)> - Failed raising 'transport messa ge received' event for message with ID=bad8ccdb-65ca-4d8c-9502-2a73f4dad1a8\179088 NServiceBus.Persistence.Raven.ConcurrencyException: A saga with the same Unique property already existed in the storage. See the inner exception for further det ails ---> Raven.Abstractions.Exceptions.ConcurrencyException: PUT attempted on document 'saga/33f2d45e-d708-43ad-a42e-a0e80155b63a' using a non current etag at Raven.Client.Connection.ServerClient.DirectBatch(IEnumerable1 commandDatas, String operationUrl) at Raven.Client.Connection.ServerClient.<>c__DisplayClass4f.<Batch>b__4e(String u) at Raven.Client.Connection.ServerClient.TryOperation[T](Func2 operation, String operationUrl, Boolean avoidThrowing, T& result) at Raven.Client.Connection.ServerClient.ExecuteWithReplication[T](String method, Func2 operation) at Raven.Client.Connection.ServerClient.Batch(IEnumerable1 commandDatas) at Raven.Client.Document.DocumentSession.SaveChanges() at NServiceBus.Persistence.Raven.RavenSessionFactory.SaveChanges() --- End of inner exception stack trace --- at NServiceBus.Unicast.UnicastBus.HandleTransportMessage(IBuilder childBuilder, TransportMessage msg) at NServiceBus.Unicast.UnicastBus.TransportMessageReceived(Object sender, TransportMessageReceivedEventArgs e) at System.EventHandler`1.Invoke(Object sender, TEventArgs e) at NServiceBus.Unicast.Transport.Transactional.TransactionalTransport.OnTransportMessageReceived(TransportMessage msg) 2012-10-12 20:44:08,249 [Worker.14] ERROR NServiceBus.Unicast.Transport.Transact ional.TransactionalTransport [(null)] <(null)> - Message has failed the maximum number of times allowed, ID=bad8ccdb-65ca-4d8c-9502-2a73f4dad1a8\179088.