Thanks everyone for contributions!

:warning: In this release we remove one (broken anyway, given Go runtime changes) metric and add three new (representing GOGC, GOMEMLIMIT and GOMAXPROCS flags) to the default collectors.NewGoCollector() collector. Given its popular usage, expect your binary to expose two additional metric.

Changes

• [CHANGE] :warning: go-collector: Remove go_memstat_lookups_total metric which was always 0; Go runtime stopped sharing pointer lookup statistics. #1577
• [FEATURE] :warning: go-collector: Add 3 default metrics: go_gc_gogc_percent, go_gc_gomemlimit_bytes and go_sched_gomaxprocs_threads as those are recommended by the Go team. #1559
• [FEATURE] go-collector: Add more information to all metrics' HELP e.g. the exact runtime/metrics sourcing each metric (if relevant). #1568 #1578
• [FEATURE] testutil: Add CollectAndFormat method. #1503
• [FEATURE] histograms: Add support for exemplars in native histograms. #1471
• [FEATURE] promhttp: Add experimental support for zstd on scrape, controlled by the request Accept-Encoding header. #1496
• [FEATURE] api/v1: Add WithLimit parameter to all API methods that supports it. #1544
• [FEATURE] prometheus: Add support for created timestamps in constant histograms and constant summaries. #1537
• [FEATURE] process-collectors: Add network usage metrics: process_network_receive_bytes_total and process_network_transmit_bytes_total. #1555
• [FEATURE] promlint: Add duplicated metric lint rule. #1472
• [BUGFIX] promlint: Relax metric type in name linter rule. #1455
• [BUGFIX] promhttp: Make sure server instrumentation wrapping supports new and future extra responseWriter methods. #1480
• [BUGFIX] testutil: Functions using compareMetricFamilies are now failing if filtered metricNames are not in the input. #1424

All commits

• feat(prometheus/testutil/promlint/validations): refine lintMetricType… by @foehammer127 in https://github.com/prometheus/client_golang/pull/1455
• Bump github.com/prometheus/client_golang from 1.18.0 to 1.19.0 in /examples/middleware by @dependabot in https://github.com/prometheus/client_golang/pull/1457
• Bump github.com/prometheus/client_model from 0.5.0 to 0.6.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1458
• Bump golang.org/x/sys from 0.16.0 to 0.17.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1459
• Bump github.com/prometheus/client_golang from 1.18.0 to 1.19.0 in /tutorial/whatsup by @dependabot in https://github.com/prometheus/client_golang/pull/1461
• Merge Release 1.19 back to main by @ArthurSens in https://github.com/prometheus/client_golang/pull/1462
• Bump the github-actions group with 2 updates by @dependabot in https://github.com/prometheus/client_golang/pull/1456
• Bump google.golang.org/protobuf from 1.32.0 to 1.33.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1466
• Bump google.golang.org/protobuf from 1.32.0 to 1.33.0 in /examples/middleware by @dependabot in https://github.com/prometheus/client_golang/pull/1467
• Bump google.golang.org/protobuf from 1.32.0 to 1.33.0 in /tutorial/whatsup by @dependabot in https://github.com/prometheus/client_golang/pull/1469
• Add LintDuplicateMetric to promlint by @bboreham in https://github.com/prometheus/client_golang/pull/1472
• Auto-update Go Collector Metrics for new Go versions by @SachinSahu431 in https://github.com/prometheus/client_golang/pull/1476
• Implement Unwrap() for responseWriterDelegator by @igor-drozdov in https://github.com/prometheus/client_golang/pull/1480
• Bump golang.org/x/sys from 0.17.0 to 0.18.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1485
• Bump github.com/prometheus/procfs from 0.12.0 to 0.13.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1486
• ci: Remove hardcoded supported Go versions from go.yml by @SachinSahu431 in https://github.com/prometheus/client_golang/pull/1489
• feat: metrics generation workflow by @SachinSahu431 in https://github.com/prometheus/client_golang/pull/1481
• fix: remove redundant go module in middleware example by @majolo in https://github.com/prometheus/client_golang/pull/1492
• chore: Refactor how base metrics are added to Sched metrics by @ArthurSens in https://github.com/prometheus/client_golang/pull/1483
• gocollector: Add regex option to allow collection of debug runtime metrics by @ArthurSens in https://github.com/prometheus/client_golang/pull/1389
• Bump github.com/prometheus/common from 0.48.0 to 0.52.3 by @dependabot in https://github.com/prometheus/client_golang/pull/1498
• chore: fix function name in comment by @oftenoccur in https://github.com/prometheus/client_golang/pull/1497
• build(deps): bump golang.org/x/net from 0.20.0 to 0.23.0 in /tutorial/whatsup by @dependabot in https://github.com/prometheus/client_golang/pull/1501
• build(deps): bump golang.org/x/net from 0.22.0 to 0.23.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1502
• feat(dependency): replace go-spew package by @dongjiang1989 in https://github.com/prometheus/client_golang/pull/1499
• build(deps): bump github.com/prometheus/common from 0.52.3 to 0.53.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1504
• build(deps): bump github.com/cespare/xxhash/v2 from 2.2.0 to 2.3.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1505
• build(deps): bump google.golang.org/protobuf from 1.33.0 to 1.34.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1506
• build(deps): bump golang.org/x/sys from 0.18.0 to 0.19.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1507
• build(deps): bump github.com/prometheus/client_model from 0.6.0 to 0.6.1 by @dependabot in https://github.com/prometheus/client_golang/pull/1508
• build(deps): bump github.com/prometheus/common from 0.48.0 to 0.53.0 in /tutorial/whatsup by @dependabot in https://github.com/prometheus/client_golang/pull/1509
• improved code more clean by @lilijreey in https://github.com/prometheus/client_golang/pull/1511
• build(deps): bump the github-actions group with 3 updates by @dependabot in https://github.com/prometheus/client_golang/pull/1510
• [CI]: Add Concurrency Grouping to GitHub Workflows by @Ishani217 in https://github.com/prometheus/client_golang/pull/1444
• Add CollectAndFormat to testutil, allowing caller to assert as they want to on the exported metric by @jcass8695 in https://github.com/prometheus/client_golang/pull/1503
• testutil compareMetricFamilies: make less error-prone by @leonnicolas in https://github.com/prometheus/client_golang/pull/1424
• improved code more clean use time.IsZero() replace t = time.Time{} by @lilijreey in https://github.com/prometheus/client_golang/pull/1515
• add native histogram exemplar support by @fatsheep9146 in https://github.com/prometheus/client_golang/pull/1471
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1514
• build(deps): bump golang.org/x/sys from 0.19.0 to 0.20.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1523
• build(deps): bump google.golang.org/protobuf from 1.34.0 to 1.34.1 by @dependabot in https://github.com/prometheus/client_golang/pull/1522
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1524
• Add PR template for changelog automation by @SachinSahu431 in https://github.com/prometheus/client_golang/pull/1517
• Auto label PRs by @SachinSahu431 in https://github.com/prometheus/client_golang/pull/1518
• Fix: Auto label PRs #1518 by @SachinSahu431 in https://github.com/prometheus/client_golang/pull/1525
• build(deps): bump github.com/prometheus/procfs from 0.13.0 to 0.15.1 by @dependabot in https://github.com/prometheus/client_golang/pull/1527
• ci: Group all changelog-related CI jobs into single one by @ArthurSens in https://github.com/prometheus/client_golang/pull/1526
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1530
• Remove synchronize trigger from changelog workflow by @SachinSahu431 in https://github.com/prometheus/client_golang/pull/1532
• feat: Support zstd compression by @mrueg in https://github.com/prometheus/client_golang/pull/1496
• Fix golangci-lint config by @SuperQ in https://github.com/prometheus/client_golang/pull/1536
• build(deps): bump github.com/prometheus/client_golang from 1.19.0 to 1.19.1 in /tutorial/whatsup by @dependabot in https://github.com/prometheus/client_golang/pull/1529
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1531
• Cleanup NOTICE file by @SuperQ in https://github.com/prometheus/client_golang/pull/1541
• Remove inlined upstream code by @SuperQ in https://github.com/prometheus/client_golang/pull/1539
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1545
• client: Add Option to provide limit query param for APIs that support it by @abbyssoul in https://github.com/prometheus/client_golang/pull/1544
• Allow creating constant histogram and summary metrics with a created timestamp by @swar8080 in https://github.com/prometheus/client_golang/pull/1537
• Update README.md by @bwplotka in https://github.com/prometheus/client_golang/pull/1556
• Temporarily remove required CI job for changelog. by @bwplotka in https://github.com/prometheus/client_golang/pull/1560
• build(deps): bump github.com/prometheus/common from 0.53.0 to 0.55.0 in /tutorial/whatsup by @dependabot in https://github.com/prometheus/client_golang/pull/1549
• build(deps): bump golang.org/x/sys from 0.20.0 to 0.21.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1552
• build(deps): bump github.com/klauspost/compress from 1.17.8 to 1.17.9 by @dependabot in https://github.com/prometheus/client_golang/pull/1553
• fix: Update Go tests by @SuperQ in https://github.com/prometheus/client_golang/pull/1562
• process_collector: collect received/transmitted bytes by @huwcbjones in https://github.com/prometheus/client_golang/pull/1555
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1561
• chore: Remove half-implemented changelog automation by @ArthurSens in https://github.com/prometheus/client_golang/pull/1564
• build(deps): bump the github-actions group across 1 directory with 3 updates by @dependabot in https://github.com/prometheus/client_golang/pull/1565
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1563
• build(deps): bump google.golang.org/protobuf from 1.34.1 to 1.34.2 by @dependabot in https://github.com/prometheus/client_golang/pull/1551
• deps: Updated to prometheus/common to 0.55 by @bwplotka in https://github.com/prometheus/client_golang/pull/1566
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1567
• tutorials: Renamed tutorial -> tutorials for consistency + fixed tutorial code. by @bwplotka in https://github.com/prometheus/client_golang/pull/1569
• go collector: add default metrics acceptance tests; adding more context to HELP by @bwplotka in https://github.com/prometheus/client_golang/pull/1568
• build(deps): bump golang.org/x/sys from 0.21.0 to 0.22.0 by @dependabot in https://github.com/prometheus/client_golang/pull/1570
• build(deps): bump the github-actions group with 3 updates by @dependabot in https://github.com/prometheus/client_golang/pull/1571
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1572
• ci: daggerize test and lint pipelines by @marcosnils in https://github.com/prometheus/client_golang/pull/1534
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1573
• Add default Go runtime metrics for /gc/gogc:percent, /gc/gomemlimit:bytes, /sched/gomaxprocs:threads by @vesari in https://github.com/prometheus/client_golang/pull/1559
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_golang/pull/1576
• Remove go_memstat_lookups_total; added runtime/metrics calculation to memstat metric's help. by @bwplotka in https://github.com/prometheus/client_golang/pull/1577
• gocollector: Attach original runtime/metrics metric name to help. by @bwplotka in https://github.com/prometheus/client_golang/pull/1578

New Contributors

• @foehammer127 made their first contribution in https://github.com/prometheus/client_golang/pull/1455
• @SachinSahu431 made their first contribution in https://github.com/prometheus/client_golang/pull/1476
• @igor-drozdov made their first contribution in https://github.com/prometheus/client_golang/pull/1480
• @majolo made their first contribution in https://github.com/prometheus/client_golang/pull/1492
• @oftenoccur made their first contribution in https://github.com/prometheus/client_golang/pull/1497
• @dongjiang1989 made their first contribution in https://github.com/prometheus/client_golang/pull/1499
• @lilijreey made their first contribution in https://github.com/prometheus/client_golang/pull/1511
• @Ishani217 made their first contribution in https://github.com/prometheus/client_golang/pull/1444
• @jcass8695 made their first contribution in https://github.com/prometheus/client_golang/pull/1503
• @leonnicolas made their first contribution in https://github.com/prometheus/client_golang/pull/1424
• @fatsheep9146 made their first contribution in https://github.com/prometheus/client_golang/pull/1471
• @abbyssoul made their first contribution in https://github.com/prometheus/client_golang/pull/1544
• @swar8080 made their first contribution in https://github.com/prometheus/client_golang/pull/1537
• @huwcbjones made their first contribution in https://github.com/prometheus/client_golang/pull/1555
• @marcosnils made their first contribution in https://github.com/prometheus/client_golang/pull/1534
• @vesari made their first contribution in https://github.com/prometheus/client_golang/pull/1559

Full Changelog: https://github.com/prometheus/client_golang/compare/v1.19.1...v1.20.0