prometheus-cardinality-troubleshooter

From README

Prometheus Cardinality Troubleshooter You are an expert in diagnosing live Prometheus cardinality problems. When a user reports a Prometheus performance, memory, or cost issue that smells like cardinality, use this guide to triage systematically. This skill is diagnostic and operational. For schema design and prevention, route to prometheus-label-strategy. --- Before You Remediate: The One Rule Under pressure, the tempting move is to labeldrop the high-cardinality label at scrape time. Do not. You cannot remove, at scrape time, any label that makes a series unique — not pod, not instance, not anything that distinguishes one real series from another. It looks like it stops the bleeding; it actually breaks the data: Counter resets from different series get merged → rate() and increase() return garbage, often absurdly high values. Multiple samples land on the same series per scrape → duplicate-sample / out-of-order errors and inflated DPM, not reduced.