The document focuses on improving website availability in ASP.NET MVC4, detailing how requests are processed by the thread pool and the impact of synchronous versus asynchronous methods. It outlines guidelines for choosing between synchronous and asynchronous action methods, particularly for network-bound or I/O-bound operations. Additionally, it provides server configuration recommendations for enhancing concurrency and latency in web service calls.

1. Improving the Availability
of Your Website in
ASP.NET MVC4
GABRIEL ENEA
MICROSOFT MVP – ASP.NET/IIS
TECHNICAL LEAD – MAXCODE
@DOTNET18 / GABRIELENEA.BLOGSPOT.COM
CODECAMP IASI, 10 NOV 2012

2. How ASP.NET Requests Are
Processed by the Thread Pool?

3. How Requests Are Processed by
the Thread Pool
free
IIS, ASP.NET Requests,
Thread Pool, .NET Fx

4. How Requests Are Processed by
the Thread Pool
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free
IIS, ASP.NET Requests,
Thread Pool, .NET Fx

5. How Requests Are Processed by
the Thread Pool
R
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busy free
IIS, ASP.NET Requests,
Thread Pool, .NET Fx

6. How Requests Are Processed by
the Thread Pool
R
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q
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t
busy
IIS, ASP.NET Requests,
Thread Pool, .NET Fx
Web Services (long running operations)

7. How Requests Are Processed by
the Thread Pool
R
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q
u
e Request Queue
s
t
busy
IIS, ASP.NET Requests,
Thread Pool, .NET Fx
Web Services

8. How Requests Are Processed by
the Thread Pool
R
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q
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e Request Queue
s
t
busy
IIS, ASP.NET Requests,
Thread Pool, .NET Fx
Web Services

9. How Requests Are Processed by
the Thread Pool 3
0
5
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q
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e Request Queue HTTP 503 Error
s Server Too Busy
t
busy
IIS, ASP.NET Requests,
Thread Pool, .NET Fx
Web Services

10. How Requests Are Processed by
the Thread Pool R
e
q
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st
3
0
5
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e Request Queue HTTP 503 Error
s Server Too Busy
t
free
IIS, ASP.NET Requests,
Thread Pool, .NET Fx
Web Services

11. How Requests Are Processed by
the Thread Pool

12. What Can We Do to Improve the
Availability?

13. What Can We Do to Improve the
Availability?

14. Using Asynchronous methods
R
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t
free
IIS, ASP.NET Requests,
Thread Pool, .NET Fx
busy
Web Services

15. .NET Asynchronous Operations patterns

16. .NET Asynchronous Operations
patterns
 Synchronous code
 .NET 1.0: Asynchronous Programming Model (APM) pattern

17. .NET Asynchronous Operations
patterns
 Synchronous code
 .NET 2.0: Event-based Asynchronous Pattern (EAP)

18. .NET Asynchronous Operations
patterns
 Synchronous code
 .NET 4.0: Task-based Asynchronous Pattern (TAP)

19. .NET Asynchronous Operations
patterns Synchronous code

 .NET 1.0: compare
 .NET 4.0:
 .NET 2.0  .NET 4.5
 async, await

20. ASP.NET MVC
Asynchronous Operations Support

21. ASP.NET MVC - Asynchronous
Operations Support
 MVC3
 AsyncController
 AsyncManager
 MVC4
 Task-based asynchronous action methods

22. DEMO

23. DEMO
 Bingoogle – Dual Search Engine
 ASP.NET MVC3 -> MVC4

24. Guidelines:
When to use synchronous or
asynchronous action methods?

25. When to use synchronous action
methods?
 The operations are simple or short-running
 Simplicity is more important than efficiency
 The operations are CPU-bound

26. When to use asynchronous action
methods? (1)
 Asynchronous methods available and using .NET 4.5
 The operations are network-bound or I/O-bound
 Parallelism is more important than simplicity of code

27. When to use asynchronous action
methods? (2)
 You want to provide a mechanism that lets users cancel
a long-running request
 Switching threads out weights the cost of the context
switch
 Testing shows that the blocking operations are a
bottleneck in site performance

28. Server Configuration for High
Concurrency/Latency Web Service Calls

29. Server Configuration for High
Concurrency/Latency Web Service Calls
 aspnet.config
<configuration>
<system.web>
<applicationPool
maxConcurrentRequestsPerCPU="5000"
maxConcurrentThreadsPerCPU="0"  HTTP.sys queue limit
requestQueueLimit="5000" />
</system.web>
</configuration>

30. Improving the Availability of Your
Website in ASP.NET MVC4
Questions?

31. Resources
Ask Google or start with..
 MSDN - Asynchronous Programming with Async and Await
 www.asp.net - Using Asynchronous Methods in ASP.NET MVC 4
 Channel9 - Mads Torgersen: Inside C# Async

32. Improving the Availability of Your
Website in ASP.NET MVC4
Please fill the evaluation
form
GABRIEL ENEA
MICROSOFT MVP – ASP.NET/IIS
TECHNICAL LEAD – MAXCODE
@DOTNET18 / GABRIELENEA.BLOGSPOT.COM

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