Review of some common and hidden performance problems with ASP.NET

1. ASP.NET
Performance
Matt Watson
Founder & CEO

2. Tip #1
Hidden
Exceptions!

3. Avoid silly exceptions

4. Use TryParse methods

5. Break on First Chance Exceptions

6. When not Breaking…

7. Subscribe to first chance exceptions

8. Viewing the output

10. Improve page load times

12. Exceptions best practices
• Avoid them at all costs 
• Find hidden exceptions with Prefix
• Track all first chance exceptions to hunt them down
• Aggregate all exceptions in production

13. Tip #2
Serialization

14. Web requests
Serialize
Request
Send
Request
Receive
Response
Headers
Download
Response
Deserialize
Response

15. Breaking down a WCF request client side

16. Breaking down a WCF request server side

17. REST call client side

18. REST call server side

19. Reading incoming data

20. Comparing different usages

21. Web request & serialization tips
• Understand payload size
• Customize JSON serializers
• Consider manually reading incoming data

22. Tip #3
SSL Overhead

23. SSL Overhead on Windows

24. IIS Architecture

25. SSL Tips
• Offload SSL to load balancer or hardware if possible
• Netscaler, F5, etc
• Use Azure Application Gateway for SSL offloading
• AWS use ELB with SSL

26. Tip #4
Garbage
collection

27. Garbage collection pauses 

28. Monitoring GC Time

29. Monitoring GC Time

30. Garbage Collection Tips
• Avoid the large object heap
• Use streams where you can
• Avoid large strings
• Server vs workstation GC mode <gcServer>
• Monitor GC performance counters

31. Tip #5
Real SQL
Performance

34. What does App Insights say?

37. SQL Connection Statistics

38. SQL Performance Tips
• SQL server performance != real world performance
• Your SQL performance reports are probably all wrong!
• Use your logging or Prefix to understand real world performance

39. Questions?