Prom-Client Files

Summary

This is our first release under the Prometheus project, and our first release for a long time.

The three main features of this release are:

• Substantially more robust support for Cluster Workers
• Equivalent support for Worker Threads
• Performance

Besides the worker improvements, this release introduces a handful of bug fixes, and a number of Typescript improvements, but is primarily a performance release. Memory use for stats storage has been reduced, as well as lookup time. Most telemetry types are between 15-35% faster, and gauges are 55% faster. Metric aggregation is up to 2.4x faster, and metrics() calls are generally around 10-35% faster depending on the sorts of labels your project uses.

What's Changed

• feat: update default type for metrics to NoLabelNameType by @Yesterday17 in https://github.com/prometheus/client_js/pull/655
• chore: add dependabot by @SimenB in https://github.com/prometheus/client_js/pull/659
• chore(deps-dev): bump eslint-config-prettier from 9.1.0 to 10.1.5 by @dependabot[bot] in https://github.com/prometheus/client_js/pull/664
• chore(deps-dev): bump express from 4.21.2 to 5.1.0 by @dependabot[bot] in https://github.com/prometheus/client_js/pull/663
• chore: upgrade to ESLint 9, and all plugins by @SimenB in https://github.com/prometheus/client_js/pull/665
• chore: drop old versions of Node by @SimenB in https://github.com/prometheus/client_js/pull/666
• chore: update Jest by @SimenB in https://github.com/prometheus/client_js/pull/667
• perf: Utilize Maps for metric collection by @jdmarshall in https://github.com/prometheus/client_js/pull/658
• Reorder number formatting tests to reflect likelihood. by @jdmarshall in https://github.com/prometheus/client_js/pull/670
• chore(deps-dev): bump prettier from 3.6.0 to 3.6.2 in the everything group by @dependabot[bot] in https://github.com/prometheus/client_js/pull/672
• chore: update lint-staged by @SimenB in https://github.com/prometheus/client_js/pull/675
• Add Code Coverage and make sure benchmarks doesn't go OOM by @jdmarshall in https://github.com/prometheus/client_js/pull/668
• Reduce function indirection in histogram.js for easier debugging by @jdmarshall in https://github.com/prometheus/client_js/pull/669
• Fix for memory leak and avoid processing expired responses by @jdmarshall in https://github.com/prometheus/client_js/pull/679
• Additional performance improvements for cluster mode by @jdmarshall in https://github.com/prometheus/client_js/pull/680
• feat: enhance error output on not valid name and label names by @ManuelLG92 in https://github.com/prometheus/client_js/pull/613
• Performance: New storage engine for stats, with improved key management by @jdmarshall in https://github.com/prometheus/client_js/pull/687
• chore(deps-dev): bump eslint-plugin-jsdoc from 51.4.1 to 52.0.0 by @dependabot[bot] in https://github.com/prometheus/client_js/pull/695
• Further refinement of key computation for performance and space. by @jdmarshall in https://github.com/prometheus/client_js/pull/691
• Performance: simplified checking for reserved label keyword by @Connormiha in https://github.com/prometheus/client_js/pull/705
• Switch to performance.now() for timing calculations. by @jdmarshall in https://github.com/prometheus/client_js/pull/725
• Fix browser compatibility by @alexgleason in https://github.com/prometheus/client_js/pull/686
• ci: Modify build actions to include benchmarks. by @jdmarshall in https://github.com/prometheus/client_js/pull/720
• Replace benchmark-regression, and compare branch performance to trunk by @jdmarshall in https://github.com/prometheus/client_js/pull/728
• chore: update prettier by @SimenB in https://github.com/prometheus/client_js/pull/731
• chore(deps-dev): bump eslint-plugin-jsdoc from 52.0.4 to 61.4.1 by @dependabot[bot] in https://github.com/prometheus/client_js/pull/729
• Add worker support by @jdmarshall in https://github.com/prometheus/client_js/pull/693
• Update to faceoff 1.1 by @jdmarshall in https://github.com/prometheus/client_js/pull/735
• security: update and pin workflow action dependencies by @krajorama in https://github.com/prometheus/client_js/pull/749
• 2.4x improvement in Cluster aggregation performance by @jdmarshall in https://github.com/prometheus/client_js/pull/692
• perf: use the faster api to collect rss by @chidam333 in https://github.com/prometheus/client_js/pull/742
• chore: add MAINTAINERS.md file by @krajorama in https://github.com/prometheus/client_js/pull/752
• Fixed types by @zigazajc007 in https://github.com/prometheus/client_js/pull/629
• chore: rename module to @prometheus/client_js by @cjihrig in https://github.com/prometheus/client_js/pull/751
• Adding example of Summary metric by @vishwa357 in https://github.com/prometheus/client_js/pull/746
• drop node 20 support by @cjihrig in https://github.com/prometheus/client_js/pull/756
• Replace usage of old node:url api with WHATWG one in pushgateway.js by @yvon-morice-wmx in https://github.com/prometheus/client_js/pull/744
• chore: Update dependabot config by @SuperQ in https://github.com/prometheus/client_js/pull/762
• chore(deps): bump actions/cache from 6.0.0 to 6.1.0 by @dependabot[bot] in https://github.com/prometheus/client_js/pull/763
• feat: add constructor with content type param to Registry class in Ty… by @us-asad in https://github.com/prometheus/client_js/pull/696
• chore: Add NOTICE file by @SuperQ in https://github.com/prometheus/client_js/pull/766
• Add Zach to maintainers list. by @jdmarshall in https://github.com/prometheus/client_js/pull/767
• Add getMetricsAsString to TypeScript definitions by @bugprone in https://github.com/prometheus/client_js/pull/768
• Add node 26 to the test matrix. by @jdmarshall in https://github.com/prometheus/client_js/pull/759
• chore: Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_js/pull/764
• Support registry as Pushgateway second argument by @bugprone in https://github.com/prometheus/client_js/pull/769
• chore: Add check-license CI job by @SuperQ in https://github.com/prometheus/client_js/pull/770
• docs: clarify cluster listener initialization by @oiahoon in https://github.com/prometheus/client_js/pull/772
• Add debug logging for metrics collection failures by @rishh09 in https://github.com/prometheus/client_js/pull/778
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_js/pull/781
• Address misreported value on exemplars for counters. by @jdmarshall in https://github.com/prometheus/client_js/pull/776
• fix(cluster): aggregate metrics in a deterministic order by @AysajanE in https://github.com/prometheus/client_js/pull/771
• Synchronize common files from prometheus/prometheus by @prombot in https://github.com/prometheus/client_js/pull/783
• Add event loop utilization to default metrics by @bugprone in https://github.com/prometheus/client_js/pull/785
• fix(types): export MetricObjectWithValues, MetricValue and related types by @milcho0604 in https://github.com/prometheus/client_js/pull/786
• chore(deps): bump actions/setup-node from 6.4.0 to 7.0.0 by @dependabot[bot] in https://github.com/prometheus/client_js/pull/797
• chore(deps): bump actions/checkout from 7.0.0 to 7.0.1 by @dependabot[bot] in https://github.com/prometheus/client_js/pull/796
• fix(types): make MetricType a string union matching runtime values by @milcho0604 in https://github.com/prometheus/client_js/pull/790
• Rename to prometheus-io to avoid naming collision on npmjs.org by @jdmarshall in https://github.com/prometheus/client_js/pull/799
• Add publication workflow for npmjs.com by @jdmarshall in https://github.com/prometheus/client_js/pull/782
• Add CHANGELOG entry and README install section for the prometheus-io rename by @krajorama in https://github.com/prometheus/client_js/pull/801
• Deprecate functions that were replaced by LabelMap by @jdmarshall in https://github.com/prometheus/client_js/pull/795
• Cluster fixes by @jdmarshall in https://github.com/prometheus/client_js/pull/789
• Support worker termination by collecting sum stats on exit. by @jdmarshall in https://github.com/prometheus/client_js/pull/806
• perf(registry): Avoid label array manipulation in the happy path. by @milcho0604 in https://github.com/prometheus/client_js/pull/804

New Contributors

• @Yesterday17 made their first contribution in https://github.com/prometheus/client_js/pull/655
• @jdmarshall made their first contribution in https://github.com/prometheus/client_js/pull/658
• @ManuelLG92 made their first contribution in https://github.com/prometheus/client_js/pull/613
• @alexgleason made their first contribution in https://github.com/prometheus/client_js/pull/686
• @krajorama made their first contribution in https://github.com/prometheus/client_js/pull/749
• @chidam333 made their first contribution in https://github.com/prometheus/client_js/pull/742
• @zigazajc007 made their first contribution in https://github.com/prometheus/client_js/pull/629
• @cjihrig made their first contribution in https://github.com/prometheus/client_js/pull/751
• @vishwa357 made their first contribution in https://github.com/prometheus/client_js/pull/746
• @yvon-morice-wmx made their first contribution in https://github.com/prometheus/client_js/pull/744
• @SuperQ made their first contribution in https://github.com/prometheus/client_js/pull/762
• @us-asad made their first contribution in https://github.com/prometheus/client_js/pull/696
• @bugprone made their first contribution in https://github.com/prometheus/client_js/pull/768
• @prombot made their first contribution in https://github.com/prometheus/client_js/pull/764
• @oiahoon made their first contribution in https://github.com/prometheus/client_js/pull/772
• @rishh09 made their first contribution in https://github.com/prometheus/client_js/pull/778
• @AysajanE made their first contribution in https://github.com/prometheus/client_js/pull/771
• @milcho0604 made their first contribution in https://github.com/prometheus/client_js/pull/786

Full Changelog: https://github.com/prometheus/client_js/compare/v15.1.3...v0.16.0