Exam essentials

Telemetry

Telemetry is jargon for the monitoring-related outputs generated by a system. They include logs, metrics, and traces. High-quality telemetry is vital for troubleshooting, tweaking, and understanding the behaviour of cloud native apps.

OpenTelemetry

The OpenTelemetry project is an incubating CNCF project that defines specifications and instrumentation aimed at making high-quality telemetry part of all cloud native apps.

Logs

Logs are a form of telemetry relating to application events and are one of the best places to look when things break. For example, application restarts, failed logins, dropped connections, and more will all be logged as events. Log data is often structured and formatted as JSON to make it easy to read and search. It’s also commonly categorised according to severity, with common severity levels including info, warning, error, and critical.

Metrics

Metrics are usually performance related data captured over long...