C# in a Nutshell, Second Edition

Chapter 29. System.Diagnostics

Diagnostics are an important part of any software system. In addition to the obvious necessity of debugging the code, diagnostics can keep track of application performance and liveness, thus indicating a problem proactively, rather than waiting for the phone call from the system administrators.

Diagnostics means more than just compiling with debug symbols turned on. Certain code paths might want to execute only when diagnostics are turned on to full power, indicated by a compile-time switch. At other times, particularly in long-running systems (such as WebService-based systems), developers want to keep a log of the system’s actions; frequently, debug reports from users are sketchy (“Um, when I clicked the button, it all just crashed”), and having a complete log of the system’s actions can be invaluable in tracking the problem down. Not only can the log consist of custom-written messages (usually to a file), but the Windows Event Log is also available for use from within this namespace.

Diagnostics also includes the ability to track the health and performance of the application; under Windows 2000 and XP, this means interaction with the Performance utility. This is a powerful tool that can be launched from the Administrative Tools program group (under Windows NT, it is called Performance Monitor). By creating appropriate performance counters within the application, .NET programmers can give the system support staff (system administrators and production ...