Diagnostics is an extremely important feature of any server application, and we have some great tools available in Microsoft Azure to effectively implement various types of diagnostics for our websites.

We need diagnostics on websites to help us track down and fix bugs and performance issues during all phases of the website's life cycle.

If we instrument our applications properly with tracing and error handling, we can determine where and why errors occur, and work out which parts of an application are taking too long to complete, causing performance issues, using tracing.

Using server logging, we can log all HTTP traffic, detailed error messages for HTTP response codes greater than or equal to 400 (which can help us diagnose why an error response is being returned), and failed request logging, which will help us detect server performance issues (possibly from under-resourcing) causing requests to fail.

In this chapter, we're going to look at...