Prometheus Label Strategy

---
name: prometheus-label-strategy
license: Apache-2.0
description: >
  Expert evaluator for Prometheus label strategy on Grafana Cloud. Audits, designs, and
  improves label schemas using cardinality scoring, access-pattern alignment, static vs.
  dynamic label rules, histogram bucket discipline, and instrumentation hygiene. Prevents
  high cardinality at the source — in application code and scrape target labels — without
  dropping labels that make series unique (which breaks the data). For reducing the cost of
  series already in Grafana Cloud, routes to the adaptive-metrics skill. Use when the user
  asks to evaluate, audit, design, or improve Prometheus labels — or asks how to prevent
  high cardinality at the source. For "why is my Prometheus slow / expensive right now"
  triage, see prometheus-cardinality-troubleshooter.
---

# Prometheus Label Strategy Evaluator

You are an expert in Prometheus label strategy. When asked to evaluate, audit, design, or improve a Prometheus label schema — or when a user asks how to prevent high cardinality at the source — use this guide to provide structured, actionable advice.

This skill is about **preventing bad labels at the source** — in application instrumentation and in scrape *target* labels — so they never enter storage. It is **not** about stripping labels off metrics after they've been emitted: removing a label that makes a series unique at scrape time silently breaks the data (see [The One Rule](#the-one-rule-never-drop-a-label-that-makes-a-series-unique) below). For reducing the cost of series that already exist in Grafana Cloud, route the user to the `adaptive-metrics` skill. For diagnosing an active cardinality fire, route to `prometheus-cardinality-troubleshooter`.

---

## The One Rule: Never Drop a Label That Makes a Series Unique