Log Levels

Log levels are a crucial part of logging in any application. They help to determine the severity and type of messages that are logged. Here's a brief overview of the common log levels:

• DEBUG: Detailed information, typically of interest only when diagnosing problems.
• INFO: Confirmation that things are working as expected.
• WARNING: An indication that something unexpected happened, or indicative of some problem in the near future (e.g., ‘disk space low’).
• ERROR: Due to a more serious problem, the software has not been able to perform some function.
• CRITICAL: A serious error, indicating that the program itself may be unable to continue running.

For more information on logging and its usage, you can check out our Logging Best Practices.

Common Use Cases

• Use DEBUG when you need to understand what is happening in the background.
• Use INFO for normal operations and to keep track of the flow of execution.
• Use WARNING to highlight situations that could potentially lead to errors.
• Use ERROR for situations where the application cannot continue normally.
• Use CRITICAL for situations where the application should stop immediately.

Debugging Example

Suppose you are trying to diagnose an issue with your application. In this case, you would typically set your log level to DEBUG to get detailed information about the application's execution.

[DEBUG] User login attempt: username = john, password = ********
[DEBUG] Authentication successful, user logged in.

debugging

Logging Levels in Practice

Here's an example of how different log levels can be used in a real-world scenario:

• INFO: Logging the successful completion of a database query.
• WARNING: Logging that the disk space is getting low.
• ERROR: Logging that the database connection has failed.
• CRITICAL: Logging that the application cannot start because it cannot connect to the database.

By using different log levels, you can control the amount of information that is logged and make it easier to diagnose issues when they arise.