Tools
Good debugging tools are essential in discovering where problems lie. You can write your own crude timing code and we will show you how. However, purpose built tools are much nicer to work with.
Many of the tools in this chapter help examine areas external to your code. We will cover profiling of code too, but it's hard to identify problems this way unless the work is purely computational. Slowdowns often happen because of actions your app initiates outside of its immediate stack, and these can be hard to debug by simply stepping through the code.
Moving through your program line-by-line slows down execution so much that it can be difficult to identify which lines are fast and which are slow. The same approach taken for fixing functional bugs cannot always be applied to fix performance issues.
One of the problems with adopting a new framework (such as ASP.NET Core) early is that it can take a while for the existing tools to be updated to work with it. We will point out when this...
