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Monitoring
Prometheus
Prometheus is one of the core observability tools in modern DevOps. It scrapes metrics from applications and infrastructure, stores them as time-series data, and allows querying through PromQL.
MetricsPromQLObservability
Key Concepts
Prometheus uses a pull model to scrape metrics.
Metrics are stored as time-series data.
PromQL is used to query and aggregate metric data.
Alertmanager is commonly paired with Prometheus for notifications.
Common Interview Questions
How does Prometheus collect metrics?
What is PromQL?
What is an exporter in Prometheus?
Use Case
Use Prometheus to collect infrastructure and application metrics for alerting and observability.
Common Use Cases
Monitoring Linux hosts and Kubernetes clusters.
Tracking request rates, latency, and error rates.
Building alerting based on infrastructure and service health.
Pros
Excellent for infrastructure and service monitoring.
Strong ecosystem with exporters and integrations.
Powerful query language and alerting model.
Cons
Not ideal for all long-term storage use cases without extension.
High-cardinality metrics can become expensive and slow.
Requires thoughtful metric design to stay effective.