# Prometheus
All Prometheus notes →1 — Metrics Deep Dive
The four Prometheus metric types — Counter, Gauge, Histogram, Summary — walked through hands-on across a Linux batch app + Node Exporter and a Windows web app + Windows Exporter, plus the histogram_quantile bucket-math caveat and the Histogram-vs-Summary tradeoff.
prometheus data-model book
Jul 18, 2026
2 — Labels and Cardinality
Label mechanics and series identity in Prometheus — how labels turn one metric name into many time series, the storage/performance cardinality math, and target relabeling vs. metric relabeling with real relabel_configs YAML.
prometheus data-model book
Jul 18, 2026
3 — TSDB Internals
The head block/WAL/compaction model underneath Prometheus's on-disk TSDB — why a cardinality spike is a storage-engine incident, not just a cost line item.
prometheus data-model book