This is the silent killer. Because Prometheus loves labels, users often get label-happy. Imagine tracking http_requests_total with a label for user_id . If you have one million users, you just created one million unique time series. Prometheus holds all of these in RAM. Once cardinality exceeds available memory, the server crashes instantly.
The theft of fire marked a pivotal moment in human history. With fire, humans could now cook their food, warm themselves, and craft tools, transforming their lives forever. This act of defiance by Prometheus not only earned him the admiration of humanity but also incurred the wrath of the gods. prometheus