A lot is changing in NServiceBus v6, especially with the changes required to support asynchronous message processing with Async/Await. Daniel Marbach shows how the v6 API update helps to avoid common Async/Await pitfalls and makes your code ready for the asynchronous APIs in the cloud. Learn how to: * Leverage the new asynchronous APIs to avoid common Async/Await pitfalls * Maximize the message throughput by using asynchronous APIs concurrently in your handlers * Write synchronous code in the new asynchronous message handlers * and last but not least, see how this relates to delicious Swiss Chocolate. If you're an existing NServiceBus user and you want to be well prepared to migrate your solutions to the latest version of NServiceBus, or you're a complete newbie to NServiceBus and want to see how it can help you avoid common Async/Await pitfalls — don't miss this webinar!

1. NServiceBus v6 API
Welcome
webinar

2. Solution Architect
Enthusiastic Software Engineer
Microsoft MVP for systems integration
@danielmarbach
particular.net/blog
planetgeek.ch

3. factory
chocolate
https://commons.wikimedia.org/wiki/File:Flag-map_of_Switzerland.svg

4. Facility
Grinding
Roasting
Blending
ProduceChocolateBar
ChocolateBarProducer(Policy)
RoastBeans
GrindBeans
BlendChocolate

6. V5Demoawait

7. as-a-service
chocolate

8. class VanillaHandler : IHandleMessages<AcquireVanilla> {
void Handle(AcquireVanilla message)
{
AcquireVanillaFromGovernmentService();
StoreVanillaUsageInDatabase();
}
}

9. class VanillaHandler : IHandleMessages<AcquireVanilla>{
void Handle(AcquireVanillamessage)
{
AcquireVanillaFromGovernmentAsync().Result;
DownloadRecipeFromBlobStorageAsync().Wait();
InsertVanillaUsageInDocumentDBAsync().Result;
StoreTelemetryDataInEventHubAsync().Wait();
}
}

10. class VanillaHandler : IHandleMessages<AcquireVanilla>{
void Handle(AcquireVanillamessage)
{
await AcquireVanillaFromGovernmentServiceAsync();
await DownloadRecipeFromBlobStorageAsync();
await InsertVanillaUsageInDocumentDBAsync();
await StoreTelemetryDataInEventHubAsync();
}
}

11. Error CS4033 The 'await' operator can only be used within an
async method. Consider marking this method with the 'async'
modifierand changing its return type to 'Task'.

12. ALT + ENTER

13. class VanillaHandler : IHandleMessages<AcquireVanilla>{
async void Handle(AcquireVanillamessage)
{
await AcquireVanillaFromGovernmentServiceAsync();
await DownloadRecipeFromBlobStorageAsync();
await InsertVanillaUsageInDocumentDBAsync();
await StoreTelemetryDataInEventHubAsync();
}
}

14. AcquireVanillaFromGovernmentServiceAsync().Result;
DownloadRecipeFromBlobStorageAsync().Wait();
InsertVanillaUsageInDocumentDBAsync().Result;
StoreTelemetryDataInEventHubAsync().Wait();
Void Handler

15. AcquireVanillaFromGovernmentServiceAsync().Result;
DownloadRecipeFromBlobStorageAsync().Wait();
InsertVanillaUsageInDocumentDBAsync().Result;
StoreTelemetryDataInEventHubAsync().Wait();
Void Handler

16. await AcquireVanillaFromGovernmentServiceAsync();
await DownloadRecipeFromBlobStorageAsync();
await InsertVanillaUsageInDocumentDBAsync();
await StoreTelemetryDataInEventHubAsync();
Async void Handler

17. await AcquireVanillaFromGovernmentServiceAsync();
await DownloadRecipeFromBlobStorageAsync();
await InsertVanillaUsageInDocumentDBAsync();
await StoreTelemetryDataInEventHubAsync();
Async void Handler

18. Version 5
Engine

19. it’s time
async
particular.net/blog/async-await-its-time

20. class VanillaHandler : IHandleMessages<AcquireVanilla>{
Task Handle(AcquireVanillamessage)
{
}
}

21. class VanillaHandler : IHandleMessages<AcquireVanilla>{
async Task Handle(AcquireVanillamessage)
{
await AcquireVanillaFromGovernmentServiceAsync();
}
}

22. class VanillaHandler : IHandleMessages<AcquireVanilla>{
async Task Handle(AcquireVanillamessage)
{
await AcquireVanillaFromGovernmentServiceAsync();
await DownloadRecipeFromBlobStorageAsync();
await InsertVanillaUsageInDocumentDBAsync();
await StoreTelemetryDataInEventHubAsync();
}
}

23. class VanillaHandler : IHandleMessages<AcquireVanilla>{
Task Handle(AcquireVanillamessage)
{
var t1 = AcquireVanillaFromGovernmentServiceAsync();
var t2 = DownloadRecipeFromBlobStorageAsync();
var t3 = InsertVanillaUsageInDocumentDBAsync();
var t4 = StoreTelemetryDataInEventHubAsync();
return Task.WhenAll(t1, t2, t3, t4);
}
}

24. Async Task Handler
await AcquireVanillaFromGovernmentServiceAsync();
await DownloadRecipeFromBlobStorageAsync();
await InsertVanillaUsageInDocumentDBAsync();
await StoreTelemetryDataInEventHubAsync();

25. But there are not only
asynchronous handlers

26. class AnotherHandler : IHandleMessages<AnotherMessage>{
Task Handle(AnotherMessage message)
{
DoSomethingSynchronous();
}
}

27. class AnotherHandler : IHandleMessages<AnotherMessage>{
async Task Handle(AnotherMessage message)
{
DoSomethingSynchronous();
}
}

28. Warning CS1998 This async method lacks 'await'
operators and will run synchronously. Consider usingthe
'await' operator to await non-blockingAPI calls, or 'await
Task.Run(...)' to do CPU-bound work on a background
thread.

29. class AnotherHandler : IHandleMessages<AnotherMessage>{
Task Handle(AnotherMessage message)
{
DoSomethingSynchronous();
return Task.CompletedTask; // for .NET 4.6
return Task.FromResult(0); //for .NET 4.5
}
}

30. state
Ambient

32. state
Ambient

33. floating state
Context
www.insideevs.com

34. class VanillaHandler : IHandleMessages<AcquireVanilla>{
async Task Handle(AcquireVanillamessage,IMessageHandlerContext context)
{
var vanilla = await webService.AcquireVanilla(message.LotNumber);
await context.Publish(new VanillaAcquired());
}
}

35. Demoawait
APIs are in early preview
V6

36. docs.particular.net
Guidance

37. Version 6
Engine
www.hdwallbackgrounds.com

38. github.com/danielmarbach/03-10-2016-AsyncWebinar
Slides, Links…

39. Q & Aawait

40. Thanks