2.37.8 / 2023-05-04

This update includes an update to the Go toolchain and an update to the Docker
dependency.

2.43.1+stringlabels / 2023-05-04

Special release build that incorporates performance improvements using
the stringlabels Go tag. This release aims to provide a more efficient and
faster solution for users managing large-scale deployments or facing performance
issues with the default Prometheus binaries.

The new labels data structure replaces the existing label/value storage with a
single string, reducing heap size and improving performance in most cases. It
enables Prometheus to use fewer system resources, particularly in
memory-intensive environments.

2.43.1 / 2023-05-03

• [BUGFIX] Labels: Set() after Del() would be ignored, which broke some relabeling rules. #12322

2.44.0-rc.1 / 2023-05-03

This is a Release Candidate for Prometheus 2.44.0, adding one bugfix over what was in v2.44.0-rc.0.

• [BUGFIX] Labels: Set after Del would be ignored, which broke some relabeling rules. #12322

This version is built with Go version 1.20.4.

2.37.7 / 2023-04-27

• [BUGFIX] Scrape: Fix prometheus_target_scrape_pool_target_limit metric not set
  before reloading. #12002

2.44.0-rc.0 / 2023-04-22

This release features several performance improvements to reduce memory and CPU usage.
The 'stringlabels' change to labels which was optional in v2.43 is now built as standard; for more
details about this code change see #10991.

A number of improvements to the experimental Native Histograms feature are included.

• [CHANGE] Remote-write: Raise default samples per send to 2,000. #12203
• [FEATURE] Remote-read: Handle native histograms. #12085, #12192
• [FEATURE] Promtool: Health and readiness check of prometheus server in CLI. #12096
• [FEATURE] PromQL: Add query_samples_total metric, the total number of samples loaded by all queries. #12251
• [ENHANCEMENT] Scrape: Reduce memory allocations on target labels. #12084
• [ENHANCEMENT] PromQL: Use faster heap method for topk() / bottomk(). #12190
• [ENHANCEMENT] Rules API: Allow filtering by rule name. #12270
• [ENHANCEMENT] Native Histograms: Various fixes and improvements. #11687, #12264, #12272
• [ENHANCEMENT] UI: Search of scraping pools is now case-insensitive. #12207
• [ENHANCEMENT] TSDB: Add an affirmative log message for successful WAL repair. #12135
• [BUGFIX] TSDB: Block compaction failed when shutting down. #12179
• [BUGFIX] TSDB: Out-of-order chunks could be ignored if the write-behind log was deleted. #12127

This version is built with Go version 1.20.3.

2.43.0+stringlabels / 2023-03-21

Special release build that incorporates performance improvements using
the stringlabels Go tag. This release aims to provide a more efficient and
faster solution for users managing large-scale deployments or facing performance
issues with the default Prometheus binaries.

The new labels data structure replaces the existing label/value storage with a
single string, reducing heap size and improving performance in most cases. It
enables Prometheus to use fewer system resources, particularly in
memory-intensive environments.

FAQ about stringlabels

2.43.0 / 2023-03-21

We are working on some performance improvements in Prometheus, which are only
built into Prometheus when compiling it using the Go tag stringlabels
(therefore they are not shipped in the default binaries). It uses a data
structure for labels that uses a single string to hold all the label/values,
resulting in a smaller heap size and some speedups in most cases. We would like
to encourage users who are interested in these improvements to help us measure
the gains on their production architecture. We are providing release artefacts
2.43.0+stringlabels and Docker images tagged v2.43.0-stringlabels with those
improvements for testing. #10991

• [FEATURE] Promtool: Add HTTP client configuration to query commands. #11487
• [FEATURE] Scrape: Add scrape_config_files to include scrape configs from different files. #12019
• [FEATURE] HTTP client: Add no_proxy to exclude URLs from proxied requests. #12098
• [FEATURE] HTTP client: Add proxy_from_enviroment to read proxies from env variables. #12098
• [ENHANCEMENT] API: Add support for setting lookback delta per query via the API. #12088
• [ENHANCEMENT] API: Change HTTP status code from 503/422 to 499 if a request is canceled. #11897
• [ENHANCEMENT] Scrape: Allow exemplars for all metric types. #11984
• [ENHANCEMENT] TSDB: Add metrics for head chunks and WAL folders size. #12013
• [ENHANCEMENT] TSDB: Automatically remove incorrect snapshot with index that is ahead of WAL. #11859
• [ENHANCEMENT] TSDB: Improve Prometheus parser error outputs to be more comprehensible. #11682
• [ENHANCEMENT] UI: Scope group by labels to metric in autocompletion. #11914
• [BUGFIX] Scrape: Fix prometheus_target_scrape_pool_target_limit metric not set before reloading. #12002
• [BUGFIX] TSDB: Correctly update prometheus_tsdb_head_chunks_removed_total and prometheus_tsdb_head_chunks metrics when reading WAL. #11858
• [BUGFIX] TSDB: Use the correct unit (seconds) when recording out-of-order append deltas in the prometheus_tsdb_sample_ooo_delta metric. #12004

2.43.0-rc.1+stringlabels / 2023-03-16

Experimental
Special release candidate build that incorporates performance improvements using
the stringlabels Go tag. This release aims to provide a more efficient and
faster solution for users managing large-scale deployments or facing performance
issues with the default Prometheus binaries.

The new labels data structure replaces the existing label/value storage with a
single string, reducing heap size and improving performance in most cases. It
enables Prometheus to use fewer system resources, particularly in
memory-intensive environments.

2.43.0-rc.1 / 2023-03-16

• [BUGFIX] Fixed a bug where changes in the Builder's Range function could lead to skipped labels during iteration (#12145)