Async ASP.NET Applications

Async ASP.NET Applications

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  DEVintersection Session AS12 Building AsynchronousASP.NET Applications
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  2 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Agenda  Quick History  When is Async Useful  Parallelism  Tips & Resources
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  3 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Async in .NET .NET Framework 1.0 / 1.1  1.0 – no async available  1.1 – APM: Async Programming Model IAsyncResult result = StartProcess(..); // continue doing other work // checking result.IsCompleted int final = EndProcess(result);
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  4 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Async in .NET .NET Framework 2.0  EAP: Event-base Async Pattern ProcessCompleted += (sender, e) => { // process the result here }; AsyncProcessStart(…);
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  5 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Async in .NET .NET Framework 4.0  TPL: Task Parallel Library  Task<int> t = ProcessAsync(…); // process other work // check t.Status, t.IsFaulted, etc. int result = t.Result;
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  6 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Async in .NET .NET Framework 4.5  async/await keywords public async Task<int> Process() { int result = await CompleteWork(); return result; }
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  7 © DEVintersection. Allrights reserved. http://www.DEVintersection.com When to Async When is it most useful?  I/O    Parallelism  Long Running Tasks
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  8 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Application Architecture 50 States Web API Web Forms Application Warnings db
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  Demo WebForms
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  10 © DEVintersection. Allrights reserved. http://www.DEVintersection.com WebForms Notes  DO NOT async your Page_Load  RegisterAsyncTask  Set Async=“true” on your .aspx page to enable async pipeline
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  Demo MVC / WebAPI
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  12 © DEVintersection. Allrights reserved. http://www.DEVintersection.com MVC / Web API Notes  Simple & Transparent  Mark method as async, return Task<T>  Use Entity Framework >= 6.1 for async methods  
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  13 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Parallelism  Task.WhenAll  Task.Run, ThreadPool.QueueUserWorkItem 
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  Demo Parallelism
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  15 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Final Comments  Avoid using Background Threads  Do not use Task.Wait()   Avoid Using Task.ContinueWith   Parallel != Async 
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  16 © DEVintersection. Allrights reserved. http://www.DEVintersection.com Resource & Links  Hanselminutes Podcast – Everything .NET programmers know about Asynchronous Programming is wrong. http://hanselminutes.com/327/everything-net-programmers-know- about-asynchronous-programming-is-wrong  Using Asynchronous Methods in ASP.NET 4.5 http://www.asp.net/web-forms/tutorials/aspnet-45/using-asynchronous- methods-in-aspnet-45  Contact Information 
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  Questions? Thank you! Don’t forgetto enter your evaluation of this session using EventBoard!