Day Of Dot Net Ann Arbor 2008

Beyond Breakpoints David Truxall, Ph.D. Debugging and Troubleshooting Principal Consultant

Production application with a problem

Finding bugs is difficult and costly

Tools and Techniques Find and Prevent Bugs

Prevent bugs with good process

Recognize the source of bugs

What is a bug? Crashes Freezes/Hangs Poor Performance Incorrect Results Security Holes Inconsistent UI

How do you debug?
Reproduce the bug
Document the bug
Investigate
Use tools
Fix it
Test the fix
Document the fix

Know the tools

Testing

Unit tests
Under your control!

Regression tests
Check fixes today
Keep bugs away tomorrow

Continuous Integration

Tools make the process work
Profilers
Load Testing
Platform-specific tools

Profiling

Load Testing
Scalability
Leaks
Interaction

Platform-specific tools
Web
Fiddler
LogParser
WebLog Expert
YSlow
Firebug
IEDeveloper Toolbar
See Scott Hanselmans’s tools list

Prevent bugs while coding
Learn the tools
Write good code
Check your work

Learn the features

Breakpoints

Watches

Code Practices
Assertions
Tracing and Logging
Symbols

Assertions Debug.Assert(predicate) Trace.Assert(predicate)

Tracing and Logging
Finding errors when you can’t debug

Symbols

Code Examination

Poor performance == Obvious File System Access Encryption

Use WinDBG to find the hard bugs

Set up and configure

SOS.dll

Symbols

ADPlus

Demo: WinDBG
Application Hang
Memory Leak

Find the Bugs!

Thank You!
[email_address]
http://dotnetjunkies.com/WebLog/davetrux/
This presentation: http://www.slideshare.net/davetrux/slideshows

by David Truxall on Oct 20, 2008