Prometheus

A book-shaped table of contents for Prometheus: monitoring foundations through architecture, data model, instrumentation, service discovery, PromQL, alerting, production operation, PCA certification, and MAANG interview prep — cross-linking existing notes instead of duplicating them.

2 — Long-Term Storage

Why single-node Prometheus has no built-in long-term-storage or HA story, and how remote_write receivers like Thanos, Cortex, Mimir, and VictoriaMetrics fill that gap at a horizontally-scaled, multi-tenant layer.

4 — High Availability

Running Prometheus HA pairs, the duplicate-sample problem that creates, deduplication strategies, and failover/DR posture for a monitoring system that is itself a dependency.

3 — Performance Tuning

Tuning Prometheus's own resource footprint and query performance — memory, CPU, WAL replay time, compaction cadence, scrape interval, and retention as levers, with cardinality as the dominant cost driver.

3 — Prometheus in the Observability Ecosystem

Where Prometheus sits in the CNCF landscape — its pull-based cloud-native origins, its companion projects, and where this book does (and doesn't yet) connect it to the wider stack.