Log Analysis Exercise

Format: Learn to find problems from logs.

Log levels:

DEBUG: Most detailed, used during development
INFO: Normal operation records ("User 123 logged in")
WARN: Potential issues ("API response slow, took 3 seconds")
ERROR: Errors but the system is still running ("Email sending failed")
FATAL: System crash-level errors ("Database connection lost")

Exercise: What log level should the following messages use?

1. "User uploaded a 10MB file" -> ?
2. "Database query took 5 seconds" -> ?
3. "Unable to connect to payment service" -> ?
4. "User password verification successful" -> ?
5. "Disk space only 5% remaining" -> ?