Can you explain what is meant by the term 'structured logging' and what are its main advantages?

Structured logging is a method of recording logs where log messages have a clearly defined structure, usually in the form of key-value pairs. Instead of plain text, logs contain data in a format suitable for automatic parsing and analysis (e.g., JSON).

Main advantages:

• Ease of analysis: Logs can be easily filtered and aggregated by keys.
• Automation: Monitoring and alerting tools can automatically process such logs.
• Increased informativeness: Instead of plain text, context can be transmitted (e.g., userID, requestID, execution time).

Example in Go using the zap library:

logger, _ := zap.NewProduction()
logger.Info("User logged in", zap.String("userID", "12345"), zap.Int("attempt", 3))

Here, the log contains a message and structured fields userID and attempt.