●Change8

v3.8.0

📦 prometheus
✨ 8 features🐛 11 fixes⚡ 1 deprecations🔧 14 symbols

Summary

This release stabilizes Native Histograms as an optional feature, requiring explicit configuration via `scrape_native_histograms`, and introduces several performance enhancements and bug fixes across PromQL and the UI. It also updates the Remote-write 2 specification adherence.

Migration Steps

  1. Upgrade to v3.8 and keep the `--enable-feature=native-histograms` flag if you were using it.
  2. At your own pace, set `scrape_native_histograms` to `true` in all relevant scrape configs to explicitly enable Native Histograms.
  3. Optionally, set `scrape_native_histograms` explicitly to `false` where Native Histograms should not be scraped.
  4. Remove the `--enable-feature=native-histograms` flag after confirming configuration changes work.
  5. You are now ready for an upgrade to v3.9.

✨ New Features

  • Native Histograms are now a stable, but optional feature, controlled by the `scrape_native_histograms` config setting.
  • Support for jwt-bearer grant-type (RFC7523 3.1) in OAuth2.
  • Added OpenContainers spec labels to Dockerfile.
  • Unified AWS service discovery for ec2, lightsail and ecs services.
  • UI now supports anchored and smoothed keywords in the promql editor.
  • UI now shows detailed relabeling steps for each discovered target.
  • Added `urlQueryEscape` to alerting template functions.
  • Promtool `push metrics` now supports Remote-Write 2.0 via the `--protobuf_message` flag.

🐛 Bug Fixes

  • Rejected Native Histogram Custom Bounds with a NaN threshold in TSDB.
  • Fixed slice indexing bug in PromQL info function on churning series.
  • Reduced lock contention on the `/api/v1/targets` API endpoint.
  • Ensured consistent handling of gauge vs. counter histograms in PromQL aggregations.
  • Allowed NHCB with -Inf as the first custom value in TSDB.
  • Fixed duplicate data loading from the API which sped up rendering of some pages.
  • Fixed `createExpressionLink` in the Old UI to correctly build /graph URLs so links from Alerts/Rules work again.
  • Avoided panic when parsing malformed `info` call in PromQL.
  • Included histograms when enforcing `sample_limit` in PromQL.
  • Fixed panic if TLS CA file is absent in configuration.
  • Fixed `histogram_fraction` for classic histograms and NHCB if the lower bound is in the first bucket.

🔧 Affected Symbols

scrape_native_histogramsRemote-write 2 specTSDBOAuth2DockerfileAWS service discoverypromql editorAlerting template functionspromtool push metricsOTLPsigv4 configinfo function (PromQL)/api/v1/targetshistogram_fraction (PromQL)

⚡ Deprecations

  • The `--enable-feature=native-histograms` flag will be a complete no-op in v3.9, and the default value of `scrape_native_histograms` will always be `false`.