What is logging?

Logging is the practice of writing messages into a log and cataloging information for later use. Logging is a cross-cutting concern, meaning it applies to every piece of your application. We talk about layers in Chapter 14, Layering and Clean Architecture, but until then, let’s just say that a cross-cutting concern affects all layers and cannot be centralized in just one; it affects a bit of everything.

Logging is essential for several reasons, including:

• Error diagnosis: Logging helps capture runtime errors and stack traces, which are invaluable for diagnosing issues after they occur, especially once an application is in production
• Debugging support: Detailed logs can provide context when debugging, helping developers understand the application’s state at the time of an error or exception
• Performance monitoring: By logging performance metrics, you can identify bottlenecks and optimize the efficiency of your application
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