Community post originally published on Medium by Dotan Horovits

OpenMetrics is finally back where it has always belonged — Prometheus format

Last month the OpenMetrics project was officially archived and folded into Prometheus. That’s the end of an open source project journey that ends exactly where it all started.

Screenshot showing OpenMetrics folding into Prometheus issue treated as "archived" on GitHub
CNCF TOC GitHub Issue #1364

It’s an interesting story. OpenMetrics was originally born as an attempt to spin off Prometheus exposition format into an independent and tool-agnostic open specification.

It was even placed under a new independent umbrella repo on GitHub called OpenObservability (no relation to my podcast OpenObservability Talks 😊)

OpenMetrics release announcement
Source: openmetrics.io

At some point a few years ago there was even an attempt to turn it into an official IETF open standard (RFC2119), which hasn’t come to fruition.

But ultimately, Prometheus itself is today a de-facto standard, at least in the cloud-native space. Many tools today provide out-of-the-box support for exporting metrics in Prometheus format.

And as to tools outside the Prometheus ecosystem, they have their own formats and haven’t jumped to switch. Because, let’s face it, as elegant as the notion of an abstract universal exposition format is, in reality these formats are quite coupled to the way the data is stored and represented internally in the tool.

In attempt to make OpenMetrics bigger than “just the Prometheus format”, it has also caused some confusion among Prometheus users, as to which format to use for exporting and receiving metric time-series data. It was even more confusing since they two are fairly similar, but then have their divergent points.

Not to mention the confusion in the broader community with the abundance of Open<X> projects.

OpenMetrics is finally back where it has always belonged — Prometheus format

Last month, July 2024, the Technical Oversight Committee of the Cloud Native Computing Foundation (CNCF TOC for short) has approved and signed the archiving of OpenMetrics and migrating it under Prometheus.

Ultimately it’s a good thing. A project can be both a tool and a specification. Just like we do with OpenTelemetry. No need for separate projects here. This merge will realign the efforts around Prometheus, simplify things and reduce confusion and overhead.

OpenMetrics is dead, long live OpenMetrics (as Prometheus format).

You can read more about open specifications in observability here.