OpenMetrics won by standardizing Prometheus without breaking it

By 2020, Prometheus metrics had already become cloud-native infrastructure's common tongue: the OpenMetrics specification cites more than 700 public exporters, thousands of native library integrations and dozens of ingestors consuming the format.

The obvious standards move would have been to redesign it. OpenMetrics did the opposite. It documented the working Prometheus text format, made minimal backward-compatible changes, and explicitly ruled sweeping changes out of scope because coordination costs were already huge.

CNCF accepted OpenMetrics as an incubating project in February 2022. CNCF described it as the officially supported exposition format for Prometheus and compatible solutions, used or supported by most CNCF projects and many wider cloud-native ecosystem projects.

Standardize the installed base

The /metrics text endpoint was easy for any service to emit and any operator to inspect.

Backward compatibility let existing exporters, libraries and ingestors migrate without a flag day.

The format kept metrics as numeric time series with labels, matching how Prometheus users already queried systems.

CNCF incubation gave the format neutral governance while preserving its Prometheus momentum.

If a de facto standard already works, the clever standard is the one that preserves migration gravity instead of proving purity.

OpenMetrics became the open metrics wire format around Prometheus rather than a competing replacement. CNCF reported production use at large enterprises and estimated Prometheus installations in the millions, with every Kubernetes instance emitting data in the ecosystem.