prometheus/client_golang v1.21.1 on GitHub

This release addresses a performance regression introduced in #1661 -- thanks to all who reported this quickly:
@chlunde, @dethi, @aaronbee @tsuna @kakkoyun 💪🏽. This patch release also fixes the iOS build.

We will be hardening the release process even further (#1759, #1761) to prevent this in future, sorry for the inconvenience!

The high concurrency optimization is planned to be eventually reintroduced, however in a much safer manner, potentially in a separate API.

[BUGFIX] prometheus: Revert of Inc, Add and Observe cumulative metric CAS optimizations (#1661), causing regressions on low concurrency cases #1757
[BUGFIX] prometheus: Fix GOOS=ios build, broken due to process_collector_* wrong build tags. #1758

All commits

Revert "exponential backoff for CAS operations on floats" and cut 1.21.1 by @bwplotka in #1757
Fix ios build for 1.21.1 by @bwplotka in #1758

Full Changelog: v1.21.0...v1.21.1

prometheus/client_golang v1.21.1 v1.21.1 / 2025-03-04 on GitHub