DevOps & CI/CD · Module 05

Monitoring with Prometheus & Grafana

Monitor hosts, containers and apps with the Four Golden Signals; Prometheus pulls metrics and queries them with PromQL, alerting on symptoms; Grafana builds dashboards on top of Prometheus.

Practice interactively →

What you will learn

• Explain why monitoring matters and what to watch on hosts, containers and apps
• Describe the Four Golden Signals
• Describe Prometheus' pull-based architecture, exporters and data model
• Write PromQL queries and symptom-based alert rules
• Connect Grafana to Prometheus to build dashboards and alerts

Lessons

1. Why Monitor, and the Four Golden Signals

   Monitoring answers "what is broken and why", feeding alerts, dashboards and trend analysis; watch hosts, containers and apps, prioritizing latency, traffic, errors and saturation.

2. Prometheus — Architecture and Data Model

   Prometheus is a monitoring system plus time-series database that scrapes metrics from exporters on a schedule; each time series is a metric name plus labels; alerts go out through Alertmanager.

3. PromQL and Alerting

   PromQL is a read-only query language for metrics — rate() for counters, aggregations like sum by, histogram_quantile for percentiles; alert rules have for, labels and annotations and should be symptom-based.

4. Grafana — Dashboards and Alerts

   Grafana is an open-source dashboard tool that stores no metrics but queries data sources such as Prometheus; panels use PromQL, with ready-made dashboards, alert rules and contact points.