1. Q: What is the primary purpose of a Logger in a software system?

A: A Logger is used to record application events, errors, or informational messages, which can help in debugging, monitoring, and auditing the behavior of an application.

2. Q: What are the common log levels and what do they represent?

A: Common log levels include:

• DEBUG – Detailed information useful during development.
• INFO – General runtime events like startup or shutdown.
• WARN – Indications of potential issues.
• ERROR – Errors that might allow the application to continue.
• FATAL – Severe errors causing application termination.

3. Q: How does a logger decide whether or not to log a message?

A: It compares the severity level of the message with the configured log level. If the message level is equal to or higher than the set level, it is logged; otherwise, it is ignored.

4. Q: What is the role of a log handler in a logger system?

A: A log handler is responsible for determining where the log messages are sent, such as to a file, the console, or a remote server.

5. Q: What is the use of a formatter in a logging system?

A: A formatter structures the log message by adding elements like timestamps, severity levels, and context to make the logs readable and useful.

6. Q: Why is thread safety important in logging?

A: In multi-threaded applications, multiple threads may try to write to the same log file simultaneously. Thread safety ensures that these operations do not interfere with each other or corrupt the log file.

7. Q: Can we change the log level of a logger during runtime?

A: Yes, many logger implementations support dynamic configuration, allowing log levels and handlers to be adjusted while the application is running.

8. Q: What is log rotation and why is it important?

A: Log rotation is the process of archiving or replacing old log files to prevent them from growing indefinitely. This helps manage disk space and ensures efficient log management.

9. Q: How does a logger support extensibility?

A: By using interfaces or abstract classes for handlers and formatters, the system allows easy addition of new log destinations (e.g., databases, cloud) or formats without changing existing code.

10. Q: What is the difference between a Logger and a LoggerBuilder?

A: A Logger handles the logging logic, while a LoggerBuilder provides a flexible way to configure and create customized logger instances with specific levels, formats, and handlers.