What are logs and monitoring?

Options

1. Logs record events your app writes; monitoring tracks metrics and alerts (Correct option)
2. Logs are passwords, and monitoring is the encryption of data
3. Logs are tests, and monitoring is the compiler of the code
4. They are the same thing, only named by different teams

Answer

Logs are a record of events your app writes; monitoring is watching metrics and alerts to know whether the system is healthy

Why

When something fails in production you can't attach a debugger, so you read the logs: timestamps, severity levels (INFO, WARN, ERROR) and messages.

Monitoring tracks numbers over time (response time, error rate, CPU) and sends alerts when they go beyond a threshold.

In containers the convention is to write logs to the standard output; for example docker logs <container> or kubectl logs <pod> shows them.

Remember

Logs = what happened. Monitoring = is it healthy now?

Key terms

• Logs, metrics, traces
• Monitoring
• kubectl
• Docker CLI
• Container
• Pod