●Change8

Migrating to Prometheus v3.9.0-rc.0

Version v3.9.0-rc.0 introduces 1 breaking change. This guide details how to update your code.

Released: 12/23/2025

1
Breaking Changes
2
Migration Steps
7
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

TSDB/api/v1/featurespromtool tsdb dumpprometheus_notifications_latency_histogram_secondsprometheus_sd_refresh metricsprometheus_tsdb_sample_ooo_deltacodemirror-promql

Breaking Changes

●Issue #1

Native Histograms are no longer experimental. The feature flag `native-histogram` is now a no-op. You must enable the configuration setting `scrape_native_histogram` to collect Native Histogram samples from exporters.

Migration Steps

  1. 1
    If you rely on Native Histograms, ensure you configure `scrape_native_histogram` in your configuration, as the `native-histogram` feature flag is now ignored.
  2. 2
    Review PromQL queries that might have been affected by fixes related to delayed name removal or OR expressions.

Release Summary

This release graduates Native Histograms to a stable feature, requiring configuration via `scrape_native_histogram`, and introduces several new features across the API, Promtool, and UI, alongside numerous bug fixes in PromQL and TSDB.

Need More Details?

View the full release notes and all changes for Prometheus v3.9.0-rc.0.

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