10 tips to make ASP.NET apps faster including: 1. Enabling kernel caching in IIS for static and dynamic content to reduce context switches. 2. Using asynchronous code, handlers, and modules to prevent thread blocking on I/O-bound operations. 3. Configuring the CLR thread pool to optimize thread usage. 4. Switching to integrated pipeline mode for a unified request processing pipeline. 5. Optimizing static file handling by selectively running managed modules. 6. Understanding the ASP.NET pipeline and placing modules strategically. 7. Avoiding direct SQL connections by using a data source. 8. Removing unused view engines to reduce overhead. 9. Avoiding

1. 10 tips to make your ASP.NET
Apps Faster
Brij Bhushan Mishra

2. Who Am I
• Brij Bhushan Mishra
• Working as a Sr Developer
• Microsoft MVP - ASP.NET/IIS since 2011
• Active in various online and offline communities
• http://codewala.net
• @code_wala
• https://www.facebook.com/codewala

3. Tip 1: Kernel Caching

4. Overview of IIS
HTTP.Sys
Kernel level
User level
Windows
Activation
Service (WAS)
WWW
Service
Svchost.exe
Worker
Process
(w3wp.exe)
Worker
Process
(w3wp.exe)
Application Pool Application Pool

5. HTTP.sys
• Lowest layer of IIS and part of networking subsystem
• Minimizes the context switch for cached content
• Caching support for static and dynamic content
• Implements request queues per application pool

6. HTTP.Sys Architecture
TCP/IP
Response Cache
Req. Queue
Send Response
HTTP Parser
Namespace Mapper
Listener
HTTP Engine
Request Response
User Level
Req. Queue Req. Queue

7. Kernel Caching
Demo

8. Reasons why it could not be cached
• Say if request is authenticated
• Only Get request would be cached
• Dynamic compression is enabled for response (e.g. gzip)
• The request is NOT HTTP 1.1 or 1.0
• Many more….
http://support.microsoft.com/kb/817445
• Doesn’t replace any other User-Mode cache

9. Tip 2: Asynchrony in ASP.NET

10. How requests are handled in ASP.NET
Kernel level
User Level
g
IIS Worker
Thread
ASP.NET
processes the
request
Process and
Pass to
ASP.NET
HTTP.Sys
ASP.NET Request processing
App Pool queue
ASP.NET Queue
CLR Thread pool
ASP.NET Request
Handler
Request

11. Options?
• Write Asynchronous pages (Web forms and MVC/Web API)
• Asynchrnous HTTP Handlers
• Asynchrnous HTTP Modules

12. Async in ASP.NET Web forms
• Set Async page attribute to use Async pipleline
• Use RegisterAsyncTask to call Async code
• ASP.NET takes care of thread affinity
Async in ASP.NET MVC/Web API
• Simple – Just mark the action method Async
• Similar for Web APIs
• Lot of APIs support Async calls (like EF6+ and many more)

13. Asynchrony in ASP.NET
Demo

14. Async scenarios
• I/O operations ( DB calls, file system, Network calls etc..)
• Parallelism
• Long running event driven (streaming, polling etc)

15. Tip 3- CLR Thread pool
• Used by every managed executable
• ASP.NET requests execute on these thread only
• Designed to auto tune itself based on system resources
• It is configurable to handle specific scenarios
• To queue work to CLR thread pool, application can call
ThreadPool.QueueUserWorkItemAPI

16. Useful Configurations
• MinWorkerThread (rate which CLR creates thread)
• MaxCurrentRequestsPerCPU (IIS 7+, 12 prior to .NET 4)
• MaxConnection
<connectionManagement>
<add address="*" maxconnection="2">
<add address="http://65.53.32.230" maxconnection="12">
</connectionManagement>

17. CLR Thread pool
Demo
http://codewala.net @code_wala https://www.facebook.com/codewala

18. Tip 4: Pipeline mode

19. Request Processing Mode- Classic
• Duplication between
IIS and ASP.NET
• ASP.NET feature cannot
be applied to non
asp.net content like
form authentication

20. Request Processing Mode- Integrated
• Unified request
processing pipeline
• Native and managed
modules
• All modules can be
applied to all type
requests

21. Tip 5: runAllManagedModulesForAllRequests
• If it set true, means all the modules would be running for all the
requests.
• You may not need this for all the static files like jpeg, js, css etc.
• Options
• Create a different application altogether for static resources where it is set as
false
• Put all static contents in a folder in same application and make it false it for
same folder
<add name="UrlRewriteModule" preCondition="managedHandler"
type="UrlRewritingNet.Web.UrlRewriteModule, UrlRewritingNet.UrlRewriter" />

22. Tip 6: ASP.NET Pipeline

23. ASP.NET Pipeline
• ASP.NET Page Request Processing
HTTPModule 1
HTTPModule 2
HTTPModule 3
HTTPModule n
HTTP Handler
Request Response
.
.
.

24. ASP.NET Pipeline
Demo

25. Tip 7: SQL Data Source?

26. SQL Data Source
Demo

27. Tip 8: Remove Unused View Engines

28. Remove Unused View Engine
• By default, ASP.NET provides two View Engines.
• It looks first for ASP.NET view engine
• Remove which is not getting used
Do you have empty methods in Global.asax?

29. Unused View Engines
Demo

30. Tip 9: Don’t write logs in inetpub

31. Tip 10: Avoid extra calls to DB?

32. Use SQL profiler to check the hits
• Run the SQL profiler when access your page.
• You might be unknowingly hitting database several times. It’s very
common using any ORM tool like Entity Framework
• This is one of the main reasons of slow applications

33. Thank You
http://codewala.net
@code_wala
https://www.facebook.com/codewala
brij.mishra@outlook.com