perf(storage/remote): avoid cloning labels without external labels by perfloop-agent · Pull Request #19503 · prometheus/prometheus

perfloop-agent · 2026-08-22T14:10:06Z

Avoid the sampled remote-read label merge when no external labels are configured. ToQueryResult has already materialized the response labels, and this path does not modify them before encoding. Reads with configured external labels retain the existing merge and source-label precedence.

Adds a focused endpoint test and a benchmark across returned-series and label counts. Checked with go test -race ./storage/remote -count=1 -run '^(TestMergeLabels|TestSampledReadEndpoint|TestSampledReadEndpointWithoutExternalLabels)$', go test --tags=dedupelabels ./storage/remote -count=1 -run '^(TestMergeLabels|TestSampledReadEndpoint|TestSampledReadEndpointWithoutExternalLabels)$', and golangci-lint run for the default, slicelabels, and dedupelabels configurations.

Which issue(s) does the PR fix:

Release notes for end users (ALL commits must be considered).

Reviewers should verify clarity and quality.

[PERF] Remote read: Avoid cloning labels for sampled reads when no external labels are configured

Workload: sampled remote read without external labels (100 series, 24 labels)

Metric	Before	After	Change
`ns/op`	325109	272038	16.3% lower
`B/op`	774362	595162	23.1% lower
`allocs/op`	1358	1258	7.4% lower
Checks: 5 passed.

Generated by Perfloop. Human sponsor: Tomás Senart. Measurements and checks.

Signed-off-by: Perfloop Agent <[email protected]>

aknuds1

LGTM, thanks!

##### [\`v3.15.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.15.0) - \[CHANGE] PromQL: A range query whose `end` was not aligned to `step` caused subqueries inside it to evaluate past the parent's last actual step, inflating `peakSamples` in the query stats and against the `query.max-samples` limit, and wasting storage I/O reading samples that were never used in the result. Add tests to prevent regression of the fix made in [#18081](prometheus/prometheus#18081). [#18598](prometheus/prometheus#18598) - \[CHANGE] PromQL: Do not register a start timestamp reset if the start timestamp hasn't changed between subsequent samples. [#19454](prometheus/prometheus#19454) - \[CHANGE] Logging: Deprecate `--log.level`; use `runtime.log_level` configuration to supply the default level. [#19511](prometheus/prometheus#19511) - \[FEATURE] Configuration: Allow changing the process log level through `runtime.log_level` on configuration reload. [#19511](prometheus/prometheus#19511) - \[FEATURE] Prometheus: Add `--auto-gomemlimit.refresh-interval` flag to periodically re-detect the container or system memory limit and update `GOMEMLIMIT` at runtime. [#18843](prometheus/prometheus#18843) - \[FEATURE] Scraping: Add support for scraping targets via Unix Domain Sockets. [#12024](prometheus/prometheus#12024). [#18091](prometheus/prometheus#18091) - \[FEATURE] scrape: Implement OM2.0 scrape format. [#18606](prometheus/prometheus#18606) - \[ENHANCEMENT] Reduce TSDB head CPU utilization when initializing. [#18001](prometheus/prometheus#18001) - \[ENHANCEMENT] Docker SD: Add labels `__meta_docker_container_image` and `__meta_docker_container_image_id`. [#19386](prometheus/prometheus#19386) - \[ENHANCEMENT] Mixin: Add a p95/p99 remote-write send-batch latency panel to the remote-write dashboard. [#19500](prometheus/prometheus#19500) - \[ENHANCEMENT] Mixin: Support native histograms in the remote-write send-batch latency panel. [#19522](prometheus/prometheus#19522) - \[ENHANCEMENT] PromQL/TSDB: The `--enable-feature=st-storage` flag now automatically enables XOR2 float chunk encoding and ST-capable histogram chunk encoding, so you no longer need to pass `xor2-encoding` and `histograms-st-encoding` alongside it. [#19518](prometheus/prometheus#19518) - \[ENHANCEMENT] Remote write / Alertmanager: upgrade sigv4 to v0.5.0, adding `session_name` and `tags` fields for STS AssumeRole sessions. The previously undocumented `service_name` field is now also documented. [#19569](prometheus/prometheus#19569) - \[ENHANCEMENT] Scraping: Support zstd-compressed scrape responses, enabled via feature flag `zstd-scrape`. [#19502](prometheus/prometheus#19502) - \[ENHANCEMENT] TSDB: Stabilize the XOR2 float chunk encoding. `--enable-feature=xor2-encoding` is deprecated; use `storage.tsdb.chunk_encoding.floats: xor2` instead. Check that other software reading the TSDB directly (e.g. Thanos sidecar) supports XOR2 before enabling. [#19461](prometheus/prometheus#19461) - \[ENHANCEMENT] TSDB: add `prometheus_tsdb_head_appenders_created_total` metric. [#19411](prometheus/prometheus#19411) - \[ENHANCEMENT] Tracing: add more spans to scrapes, API queries and rule evaluations. [#19410](prometheus/prometheus#19410) - \[ENHANCEMENT] UI: Show the effective configuration for each scrape pool on the Targets and Service Discovery pages. [#19384](prometheus/prometheus#19384) - \[ENHANCEMENT] scrape: Enable start time synthesis for summary `_count` and `_sum` series in scrape appender v2. [#19323](prometheus/prometheus#19323) - \[ENHANCEMENT] scrape: stop all pools in parallel for faster shutdowns. [#19295](prometheus/prometheus#19295) - \[ENHANCEMENT] storage/remote: Add undocumented failed\_request\_logging config field to debug log remote write V2 requests on send errors. [#19249](prometheus/prometheus#19249) - \[ENHANCEMENT] TSDB: Add fast path for XOR chunk decompression to speed up queries. [#18049](prometheus/prometheus#18049) - \[ENHANCEMENT] UI: Improve native histogram table formatting and add a background bar indicating the bucket count. [#19332](prometheus/prometheus#19332) - \[ENHANCEMENT] TSDB: Add `prometheus_tsdb_head_series_pending_commit_underflow_total` to report pending-sample reservation underflows. [#19470](prometheus/prometheus#19470) - \[PERF] AWS SD: Build RDS cluster labels once per cluster instead of once per instance. [#19504](prometheus/prometheus#19504) - \[PERF] AWS SD: Describe RDS instances of different clusters concurrently, bounded by `request_concurrency`. [#19506](prometheus/prometheus#19506) - \[PERF] AWS SD: Describe each ElastiCache resource once per refresh instead of twice. [#19585](prometheus/prometheus#19585) - \[PERF] Remote read: Avoid cloning labels for sampled reads when no external labels are configured. [#19503](prometheus/prometheus#19503) - \[PERF] Remote write: Reuse OTLP converter scratch state between requests. [#19388](prometheus/prometheus#19388) - \[PERF] scrape: conversion from classic to native histograms should only parse start times when enabled. [#19446](prometheus/prometheus#19446) - \[BUGFIX] PromQL: Fix `info()` enrichment for composite expressions with mixed `@`/offset references or selector-free vector branches, preventing metadata from being evaluated at an unrelated timestamp. [#19387](prometheus/prometheus#19387) - \[BUGFIX] PromQL: Fix info() enrichment when input series use different subsets of identifying labels. [#19557](prometheus/prometheus#19557) - \[BUGFIX] PromQL: Preserve metric-name dropping through the info function when delayed name removal is enabled. [#19413](prometheus/prometheus#19413) - \[BUGFIX] TSDB: Don't silently drop samples when head garbage collection removes a series while it is being appended to. [#19272](prometheus/prometheus#19272) - \[BUGFIX] TSDB: Keep series with uncommitted samples during selected- and stale-series compaction, including when appenders overlap. [#19470](prometheus/prometheus#19470) - \[BUGFIX] TSDB: Do not retain head series after a synthetic start-timestamp zero sample is rejected. [#19470](prometheus/prometheus#19470) - \[BUGFIX] TSDB: Prevent query panics during series eviction after WAL replay. [#19664](prometheus/prometheus#19664) - \[BUGFIX] TSDB: fix potential deadlock between mmapSeriesChunks and gcSeries. [#19460](prometheus/prometheus#19460) - \[BUGFIX] TSDB: fix default block reload interval for custom options. [#19368](prometheus/prometheus#19368) - \[BUGFIX] AWS SD: Do not crash on serverless MSK clusters or MSK clusters without Open Monitoring. [#19194](prometheus/prometheus#19194) - \[BUGFIX] AWS SD: Do not panic when the ElastiCache API omits optional fields of a serverless cache or cache cluster. [#19435](prometheus/prometheus#19435) - \[BUGFIX] AWS SD: Reject non-positive `request_concurrency` instead of hanging service discovery indefinitely. [#19524](prometheus/prometheus#19524) - \[BUGFIX] Discovery/AWS: Avoid a panic when discovering standalone ECS tasks with custom task groups. [#19302](prometheus/prometheus#19302) - \[BUGFIX] Discovery: Do not panic in AWS Lightsail service discovery when an instance is missing optional fields such as availability zone, blueprint, bundle, name, state or support code. [#19324](prometheus/prometheus#19324) - \[BUGFIX] Discovery: delete the stale `prometheus_sd_last_update_timestamp_seconds` series for a config that is removed on reload. [#19131](prometheus/prometheus#19131) - \[BUGFIX] HTTP: Avoid truncating compressed responses when handlers set Content-Length. [#19661](prometheus/prometheus#19661) - \[BUGFIX] IONOS SD: Do not panic when the API response omits the server, NIC or volume collections, or a server's properties. [#19438](prometheus/prometheus#19438) - \[BUGFIX] Metadata will not affect the number of Remote Write v2 shards. [#19218](prometheus/prometheus#19218) - \[BUGFIX] Mixins: Fix label mismatches that prevented PrometheusHAGroupNotIngestingSamples and PrometheusHAGroupCrashlooping from firing. [#19444](prometheus/prometheus#19444) - \[BUGFIX] Native histograms: `DetectReset` no longer misses a counter reset when a populated bucket behind an empty one disappears, which could make histogram `rate()`/`increase()` undercount. [#19367](prometheus/prometheus#19367) - \[BUGFIX] Never skip histogram buckets for histogram\_stddev and histogram\_stdvar functions. [#19521](prometheus/prometheus#19521) - \[BUGFIX] OTLP: Do not abort an entire OTLP payload ingestion if one metric has no datapoints. [#19343](prometheus/prometheus#19343) - \[BUGFIX] PromQL: Fix FastRegexMatcher false-positive match when a capturing group is directly adjacent to a literal (e.g. `.*\|(foo)\|.*`). [#19516](prometheus/prometheus#19516) - \[BUGFIX] PromQL: Fix a panic in range selectors using the experimental `anchored` or `smoothed` modifier when the selected series has no samples inside the query window, for example a query evaluated inside a scrape gap. [#19431](prometheus/prometheus#19431) - \[BUGFIX] PromQL: Fix empty results when a subquery with `@` is used as the matrix argument of a call that is not step-invariant (for example `quantile_over_time(scalar(x), metric[...:...] @ T)`). [#19187](prometheus/prometheus#19187) - \[BUGFIX] PromQL: Make the "found duplicate series for the match group" many-to-many matching error message deterministic by sorting the two duplicate labels. [#18810](prometheus/prometheus#18810) - \[BUGFIX] PromQL: Preserve parentheses around duration literals on Expr.String() round-trip. [#19403](prometheus/prometheus#19403) - \[BUGFIX] PromQL: Reject duration-expression offsets and `@ start()` / `@ end()` before range selectors, matching the existing rejection of literal offsets and `@ <timestamp>`. [#19406](prometheus/prometheus#19406) - \[BUGFIX] PromQL: Report the position of the histogram argument rather than of a scalar argument in the native histogram NaN observation annotations of `histogram_quantile` and `histogram_fraction`. [#19330](prometheus/prometheus#19330) - \[BUGFIX] PromQL: info() now applies the @ modifier/offset when evaluating the info series, so info(v @ T) enriches as of T consistently instead of depending on the query start/eval time. [#19266](prometheus/prometheus#19266) - \[BUGFIX] Rules: Fix a panic when a rule manager created without a logger loads a rule file containing multiple YAML documents. [#19433](prometheus/prometheus#19433) - \[BUGFIX] Scrape: Do not append a stale marker for a series that is still exposed when the storage returns a new series reference for it. [#19328](prometheus/prometheus#19328) - \[BUGFIX] Scrape: JSON log formatter correctly format scrape target info. [#19472](prometheus/prometheus#19472) - \[BUGFIX] TSDB: Fix in-order chunk ID overflow by wrapping head chunk IDs modulo 2^23 so they never collide with the out-of-order flag bit. [#19450](prometheus/prometheus#19450) - \[BUGFIX] TSDB: Fix out-of-order chunk ID overflow by wrapping `firstOOOChunkID` modulo 2^23 instead of growing unbounded. [#19216](prometheus/prometheus#19216) - \[BUGFIX] UI: Remove an extraneous X-axis tick mark in the native histogram chart when using the "linear" display mode. [#19326](prometheus/prometheus#19326) - \[BUGFIX] discovery/aws: Avoid a panic when an ElastiCache ARN is missing its resource ID. [#19333](prometheus/prometheus#19333) - \[BUGFIX] discovery/aws: Do not panic on MSK clusters whose optional API fields are absent. [#19584](prometheus/prometheus#19584) - \[BUGFIX] discovery/aws: Do not panic when the EC2 API omits optional instance fields. [#19512](prometheus/prometheus#19512) - \[BUGFIX] discovery/aws: Don't panic on ECS tasks with absent optional fields. [#19396](prometheus/prometheus#19396) - \[BUGFIX] discovery/aws: MSK Optional Custom Configuration Fields [#19422](prometheus/prometheus#19422). [#19422](prometheus/prometheus#19422) - \[BUGFIX] discovery/ionos: Fix panic when the IONOS API omits optional server fields. [#19418](prometheus/prometheus#19418) - \[BUGFIX] discovery/kubernetes: Populate `__meta_kubernetes_service_loadbalancer_ip` from `status.loadBalancer.ingress`, falling back to deprecated `spec.loadBalancerIP`. [#19404](prometheus/prometheus#19404) - \[BUGFIX] histogram: Fix Compact moving buckets to wrong indices, and producing negative bucket counts for integer histograms, when more than one span is merged in the same pass. [#19312](prometheus/prometheus#19312) - \[BUGFIX] promtool: Fixed `tsdb dump` silently dropping native histogram samples. [#18051](prometheus/prometheus#18051) - \[BUGFIX] scrape: fix data race in `Manager.TargetsDroppedCounts` to avoid miscounting dropped targets. [#19304](prometheus/prometheus#19304) - \[BUGFIX] scrape: fix nil histogram when native and classic histograms are mixed in one metric family. [#19452](prometheus/prometheus#19452) - \[BUGFIX] TSDB: Fix WAL and GC log messages to emit human-readable duration strings instead of nanosecond integers. [#19307](prometheus/prometheus#19307) - \[BUGFIX] TSDB: Avoid WAL corruption after a failed WAL write in Agent mode. [#19700](prometheus/prometheus#19700) - \[BUGFIX] Agent: Ignore unknown WAL record types, to help users rolling back. [#19814](prometheus/prometheus#19814)

…→ v3.15.0) (#769) This PR contains the following updates: | Package | Update | Change | |---|---|---| | [quay.io/prometheus/prometheus](https://github.com/prometheus/prometheus) | minor | `v3.14.0` → `v3.15.0` | --- ### Release Notes <details> <summary>prometheus/prometheus (quay.io/prometheus/prometheus)</summary> ### [`v3.15.0`](https://github.com/prometheus/prometheus/releases/tag/v3.15.0): 3.15.0 / 2026-09-24 [Compare Source](prometheus/prometheus@v3.14.0...v3.15.0) - \[CHANGE] PromQL: A range query whose `end` was not aligned to `step` caused subqueries inside it to evaluate past the parent's last actual step, inflating `peakSamples` in the query stats and against the `query.max-samples` limit, and wasting storage I/O reading samples that were never used in the result. Add tests to prevent regression of the fix made in [#18081](prometheus/prometheus#18081). [#18598](prometheus/prometheus#18598) - \[CHANGE] PromQL: Do not register a start timestamp reset if the start timestamp hasn't changed between subsequent samples. [#19454](prometheus/prometheus#19454) - \[CHANGE] Logging: Deprecate `--log.level`; use `runtime.log_level` configuration to supply the default level. [#19511](prometheus/prometheus#19511) - \[FEATURE] Configuration: Allow changing the process log level through `runtime.log_level` on configuration reload. [#19511](prometheus/prometheus#19511) - \[FEATURE] Prometheus: Add `--auto-gomemlimit.refresh-interval` flag to periodically re-detect the container or system memory limit and update `GOMEMLIMIT` at runtime. [#18843](prometheus/prometheus#18843) - \[FEATURE] Scraping: Add support for scraping targets via Unix Domain Sockets. [#12024](prometheus/prometheus#12024). [#18091](prometheus/prometheus#18091) - \[FEATURE] scrape: Implement OM2.0 scrape format. [#18606](prometheus/prometheus#18606) - \[ENHANCEMENT] Reduce TSDB head CPU utilization when initializing. [#18001](prometheus/prometheus#18001) - \[ENHANCEMENT] Docker SD: Add labels `__meta_docker_container_image` and `__meta_docker_container_image_id`. [#19386](prometheus/prometheus#19386) - \[ENHANCEMENT] Mixin: Add a p95/p99 remote-write send-batch latency panel to the remote-write dashboard. [#19500](prometheus/prometheus#19500) - \[ENHANCEMENT] Mixin: Support native histograms in the remote-write send-batch latency panel. [#19522](prometheus/prometheus#19522) - \[ENHANCEMENT] PromQL/TSDB: The `--enable-feature=st-storage` flag now automatically enables XOR2 float chunk encoding and ST-capable histogram chunk encoding, so you no longer need to pass `xor2-encoding` and `histograms-st-encoding` alongside it. [#19518](prometheus/prometheus#19518) - \[ENHANCEMENT] Remote write / Alertmanager: upgrade sigv4 to v0.5.0, adding `session_name` and `tags` fields for STS AssumeRole sessions. The previously undocumented `service_name` field is now also documented. [#19569](prometheus/prometheus#19569) - \[ENHANCEMENT] Scraping: Support zstd-compressed scrape responses, enabled via feature flag `zstd-scrape`. [#19502](prometheus/prometheus#19502) - \[ENHANCEMENT] TSDB: Stabilize the XOR2 float chunk encoding. `--enable-feature=xor2-encoding` is deprecated; use `storage.tsdb.chunk_encoding.floats: xor2` instead. Check that other software reading the TSDB directly (e.g. Thanos sidecar) supports XOR2 before enabling. [#19461](prometheus/prometheus#19461) - \[ENHANCEMENT] TSDB: add `prometheus_tsdb_head_appenders_created_total` metric. [#19411](prometheus/prometheus#19411) - \[ENHANCEMENT] Tracing: add more spans to scrapes, API queries and rule evaluations. [#19410](prometheus/prometheus#19410) - \[ENHANCEMENT] UI: Show the effective configuration for each scrape pool on the Targets and Service Discovery pages. [#19384](prometheus/prometheus#19384) - \[ENHANCEMENT] scrape: Enable start time synthesis for summary `_count` and `_sum` series in scrape appender v2. [#19323](prometheus/prometheus#19323) - \[ENHANCEMENT] scrape: stop all pools in parallel for faster shutdowns. [#19295](prometheus/prometheus#19295) - \[ENHANCEMENT] storage/remote: Add undocumented failed\_request\_logging config field to debug log remote write V2 requests on send errors. [#19249](prometheus/prometheus#19249) - \[ENHANCEMENT] TSDB: Add fast path for XOR chunk decompression to speed up queries. [#18049](prometheus/prometheus#18049) - \[ENHANCEMENT] UI: Improve native histogram table formatting and add a background bar indicating the bucket count. [#19332](prometheus/prometheus#19332) - \[ENHANCEMENT] TSDB: Add `prometheus_tsdb_head_series_pending_commit_underflow_total` to report pending-sample reservation underflows. [#19470](prometheus/prometheus#19470) - \[PERF] AWS SD: Build RDS cluster labels once per cluster instead of once per instance. [#19504](prometheus/prometheus#19504) - \[PERF] AWS SD: Describe RDS instances of different clusters concurrently, bounded by `request_concurrency`. [#19506](prometheus/prometheus#19506) - \[PERF] AWS SD: Describe each ElastiCache resource once per refresh instead of twice. [#19585](prometheus/prometheus#19585) - \[PERF] Remote read: Avoid cloning labels for sampled reads when no external labels are configured. [#19503](prometheus/prometheus#19503) - \[PERF] Remote write: Reuse OTLP converter scratch state between requests. [#19388](prometheus/prometheus#19388) - \[PERF] scrape: conversion from classic to native histograms should only parse start times when enabled. [#19446](prometheus/prometheus#19446) - \[BUGFIX] PromQL: Fix `info()` enrichment for composite expressions with mixed `@`/offset references or selector-free vector branches, preventing metadata from being evaluated at an unrelated timestamp. [#19387](prometheus/prometheus#19387) - \[BUGFIX] PromQL: Fix info() enrichment when input series use different subsets of identifying labels. [#19557](prometheus/prometheus#19557) - \[BUGFIX] PromQL: Preserve metric-name dropping through the info function when delayed name removal is enabled. [#19413](prometheus/prometheus#19413) - \[BUGFIX] TSDB: Don't silently drop samples when head garbage collection removes a series while it is being appended to. [#19272](prometheus/prometheus#19272) - \[BUGFIX] TSDB: Keep series with uncommitted samples during selected- and stale-series compaction, including when appenders overlap. [#19470](prometheus/prometheus#19470) - \[BUGFIX] TSDB: Do not retain head series after a synthetic start-timestamp zero sample is rejected. [#19470](prometheus/prometheus#19470) - \[BUGFIX] TSDB: Prevent query panics during series eviction after WAL replay. [#19664](prometheus/prometheus#19664) - \[BUGFIX] TSDB: fix potential deadlock between mmapSeriesChunks and gcSeries. [#19460](prometheus/prometheus#19460) - \[BUGFIX] TSDB: fix default block reload interval for custom options. [#19368](prometheus/prometheus#19368) - \[BUGFIX] AWS SD: Do not crash on serverless MSK clusters or MSK clusters without Open Monitoring. [#19194](prometheus/prometheus#19194) - \[BUGFIX] AWS SD: Do not panic when the ElastiCache API omits optional fields of a serverless cache or cache cluster. [#19435](prometheus/prometheus#19435) - \[BUGFIX] AWS SD: Reject non-positive `request_concurrency` instead of hanging service discovery indefinitely. [#19524](prometheus/prometheus#19524) - \[BUGFIX] Discovery/AWS: Avoid a panic when discovering standalone ECS tasks with custom task groups. [#19302](prometheus/prometheus#19302) - \[BUGFIX] Discovery: Do not panic in AWS Lightsail service discovery when an instance is missing optional fields such as availability zone, blueprint, bundle, name, state or support code. [#19324](prometheus/prometheus#19324) - \[BUGFIX] Discovery: delete the stale `prometheus_sd_last_update_timestamp_seconds` series for a config that is removed on reload. [#19131](prometheus/prometheus#19131) - \[BUGFIX] HTTP: Avoid truncating compressed responses when handlers set Content-Length. [#19661](prometheus/prometheus#19661) - \[BUGFIX] IONOS SD: Do not panic when the API response omits the server, NIC or volume collections, or a server's properties. [#19438](prometheus/prometheus#19438) - \[BUGFIX] Metadata will not affect the number of Remote Write v2 shards. [#19218](prometheus/prometheus#19218) - \[BUGFIX] Mixins: Fix label mismatches that prevented PrometheusHAGroupNotIngestingSamples and PrometheusHAGroupCrashlooping from firing. [#19444](prometheus/prometheus#19444) - \[BUGFIX] Native histograms: `DetectReset` no longer misses a counter reset when a populated bucket behind an empty one disappears, which could make histogram `rate()`/`increase()` undercount. [#19367](prometheus/prometheus#19367) - \[BUGFIX] Never skip histogram buckets for histogram\_stddev and histogram\_stdvar functions. [#19521](prometheus/prometheus#19521) - \[BUGFIX] OTLP: Do not abort an entire OTLP payload ingestion if one metric has no datapoints. [#19343](prometheus/prometheus#19343) - \[BUGFIX] PromQL: Fix FastRegexMatcher false-positive match when a capturing group is directly adjacent to a literal (e.g. `.*\|(foo)\|.*`). [#19516](prometheus/prometheus#19516) - \[BUGFIX] PromQL: Fix a panic in range selectors using the experimental `anchored` or `smoothed` modifier when the selected series has no samples inside the query window, for example a query evaluated inside a scrape gap. [#19431](prometheus/prometheus#19431) - \[BUGFIX] PromQL: Fix empty results when a subquery with `@` is used as the matrix argument of a call that is not step-invariant (for example `quantile_over_time(scalar(x), metric[...:...] @ T)`). [#19187](prometheus/prometheus#19187) - \[BUGFIX] PromQL: Make the "found duplicate series for the match group" many-to-many matching error message deterministic by sorting the two duplicate labels. [#18810](prometheus/prometheus#18810) - \[BUGFIX] PromQL: Preserve parentheses around duration literals on Expr.String() round-trip. [#19403](prometheus/prometheus#19403) - \[BUGFIX] PromQL: Reject duration-expression offsets and `@ start()` / `@ end()` before range selectors, matching the existing rejection of literal offsets and `@ <timestamp>`. [#19406](prometheus/prometheus#19406) - \[BUGFIX] PromQL: Report the position of the histogram argument rather than of a scalar argument in the native histogram NaN observation annotations of `histogram_quantile` and `histogram_fraction`. [#19330](prometheus/prometheus#19330) - \[BUGFIX] PromQL: info() now applies the @ modifier/offset when evaluating the info series, so info(v @ T) enriches as of T consistently instead of depending on the query start/eval time. [#19266](prometheus/prometheus#19266) - \[BUGFIX] Rules: Fix a panic when a rule manager created without a logger loads a rule file containing multiple YAML documents. [#19433](prometheus/prometheus#19433) - \[BUGFIX] Scrape: Do not append a stale marker for a series that is still exposed when the storage returns a new series reference for it. [#19328](prometheus/prometheus#19328) - \[BUGFIX] Scrape: JSON log formatter correctly format scrape target info. [#19472](prometheus/prometheus#19472) - \[BUGFIX] TSDB: Fix in-order chunk ID overflow by wrapping head chunk IDs modulo 2^23 so they never collide with the out-of-order flag bit. [#19450](prometheus/prometheus#19450) - \[BUGFIX] TSDB: Fix out-of-order chunk ID overflow by wrapping `firstOOOChunkID` modulo 2^23 instead of growing unbounded. [#19216](prometheus/prometheus#19216) - \[BUGFIX] UI: Remove an extraneous X-axis tick mark in the native histogram chart when using the "linear" display mode. [#19326](prometheus/prometheus#19326) - \[BUGFIX] discovery/aws: Avoid a panic when an ElastiCache ARN is missing its resource ID. [#19333](prometheus/prometheus#19333) - \[BUGFIX] discovery/aws: Do not panic on MSK clusters whose optional API fields are absent. [#19584](prometheus/prometheus#19584) - \[BUGFIX] discovery/aws: Do not panic when the EC2 API omits optional instance fields. [#19512](prometheus/prometheus#19512) - \[BUGFIX] discovery/aws: Don't panic on ECS tasks with absent optional fields. [#19396](prometheus/prometheus#19396) - \[BUGFIX] discovery/aws: MSK Optional Custom Configuration Fields [#19422](prometheus/prometheus#19422). [#19422](prometheus/prometheus#19422) - \[BUGFIX] discovery/ionos: Fix panic when the IONOS API omits optional server fields. [#19418](prometheus/prometheus#19418) - \[BUGFIX] discovery/kubernetes: Populate `__meta_kubernetes_service_loadbalancer_ip` from `status.loadBalancer.ingress`, falling back to deprecated `spec.loadBalancerIP`. [#19404](prometheus/prometheus#19404) - \[BUGFIX] histogram: Fix Compact moving buckets to wrong indices, and producing negative bucket counts for integer histograms, when more than one span is merged in the same pass. [#19312](prometheus/prometheus#19312) - \[BUGFIX] promtool: Fixed `tsdb dump` silently dropping native histogram samples. [#18051](prometheus/prometheus#18051) - \[BUGFIX] scrape: fix data race in `Manager.TargetsDroppedCounts` to avoid miscounting dropped targets. [#19304](prometheus/prometheus#19304) - \[BUGFIX] scrape: fix nil histogram when native and classic histograms are mixed in one metric family. [#19452](prometheus/prometheus#19452) - \[BUGFIX] TSDB: Fix WAL and GC log messages to emit human-readable duration strings instead of nanosecond integers. [#19307](prometheus/prometheus#19307) - \[BUGFIX] TSDB: Avoid WAL corruption after a failed WAL write in Agent mode. [#19700](prometheus/prometheus#19700) - \[BUGFIX] Agent: Ignore unknown WAL record types, to help users rolling back. [#19814](prometheus/prometheus#19814) </details> --- ### Configuration 📅 **Schedule**: (in timezone Europe/London) - Branch creation - At any time (no schedule defined) - Automerge - At any time (no schedule defined) 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate CLI](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.hayden.moe/hayden/phoebe/pulls/769

…➔ v3.15.0) (#2199) This PR contains the following updates: | Package | Update | Change | |---|---|---| | [quay.io/prometheus/prometheus](https://github.com/prometheus/prometheus) | minor | `v3.14.0` → `v3.15.0` | --- > ⚠️ **Warning** > > Some dependencies could not be looked up. Check the [Dependency Dashboard](issues/567) for more information. --- ### Release Notes <details> <summary>prometheus/prometheus (quay.io/prometheus/prometheus)</summary> ### [`v3.15.0`](https://github.com/prometheus/prometheus/releases/tag/v3.15.0): 3.15.0 / 2026-09-24 [Compare Source](prometheus/prometheus@v3.14.0...v3.15.0) - \[CHANGE] PromQL: A range query whose `end` was not aligned to `step` caused subqueries inside it to evaluate past the parent's last actual step, inflating `peakSamples` in the query stats and against the `query.max-samples` limit, and wasting storage I/O reading samples that were never used in the result. Add tests to prevent regression of the fix made in [#18081](prometheus/prometheus#18081). [#18598](prometheus/prometheus#18598) - \[CHANGE] PromQL: Do not register a start timestamp reset if the start timestamp hasn't changed between subsequent samples. [#19454](prometheus/prometheus#19454) - \[CHANGE] Logging: Deprecate `--log.level`; use `runtime.log_level` configuration to supply the default level. [#19511](prometheus/prometheus#19511) - \[FEATURE] Configuration: Allow changing the process log level through `runtime.log_level` on configuration reload. [#19511](prometheus/prometheus#19511) - \[FEATURE] Prometheus: Add `--auto-gomemlimit.refresh-interval` flag to periodically re-detect the container or system memory limit and update `GOMEMLIMIT` at runtime. [#18843](prometheus/prometheus#18843) - \[FEATURE] Scraping: Add support for scraping targets via Unix Domain Sockets. [#12024](prometheus/prometheus#12024). [#18091](prometheus/prometheus#18091) - \[FEATURE] scrape: Implement OM2.0 scrape format. [#18606](prometheus/prometheus#18606) - \[ENHANCEMENT] Reduce TSDB head CPU utilization when initializing. [#18001](prometheus/prometheus#18001) - \[ENHANCEMENT] Docker SD: Add labels `__meta_docker_container_image` and `__meta_docker_container_image_id`. [#19386](prometheus/prometheus#19386) - \[ENHANCEMENT] Mixin: Add a p95/p99 remote-write send-batch latency panel to the remote-write dashboard. [#19500](prometheus/prometheus#19500) - \[ENHANCEMENT] Mixin: Support native histograms in the remote-write send-batch latency panel. [#19522](prometheus/prometheus#19522) - \[ENHANCEMENT] PromQL/TSDB: The `--enable-feature=st-storage` flag now automatically enables XOR2 float chunk encoding and ST-capable histogram chunk encoding, so you no longer need to pass `xor2-encoding` and `histograms-st-encoding` alongside it. [#19518](prometheus/prometheus#19518) - \[ENHANCEMENT] Remote write / Alertmanager: upgrade sigv4 to v0.5.0, adding `session_name` and `tags` fields for STS AssumeRole sessions. The previously undocumented `service_name` field is now also documented. [#19569](prometheus/prometheus#19569) - \[ENHANCEMENT] Scraping: Support zstd-compressed scrape responses, enabled via feature flag `zstd-scrape`. [#19502](prometheus/prometheus#19502) - \[ENHANCEMENT] TSDB: Stabilize the XOR2 float chunk encoding. `--enable-feature=xor2-encoding` is deprecated; use `storage.tsdb.chunk_encoding.floats: xor2` instead. Check that other software reading the TSDB directly (e.g. Thanos sidecar) supports XOR2 before enabling. [#19461](prometheus/prometheus#19461) - \[ENHANCEMENT] TSDB: add `prometheus_tsdb_head_appenders_created_total` metric. [#19411](prometheus/prometheus#19411) - \[ENHANCEMENT] Tracing: add more spans to scrapes, API queries and rule evaluations. [#19410](prometheus/prometheus#19410) - \[ENHANCEMENT] UI: Show the effective configuration for each scrape pool on the Targets and Service Discovery pages. [#19384](prometheus/prometheus#19384) - \[ENHANCEMENT] scrape: Enable start time synthesis for summary `_count` and `_sum` series in scrape appender v2. [#19323](prometheus/prometheus#19323) - \[ENHANCEMENT] scrape: stop all pools in parallel for faster shutdowns. [#19295](prometheus/prometheus#19295) - \[ENHANCEMENT] storage/remote: Add undocumented failed\_request\_logging config field to debug log remote write V2 requests on send errors. [#19249](prometheus/prometheus#19249) - \[ENHANCEMENT] TSDB: Add fast path for XOR chunk decompression to speed up queries. [#18049](prometheus/prometheus#18049) - \[ENHANCEMENT] UI: Improve native histogram table formatting and add a background bar indicating the bucket count. [#19332](prometheus/prometheus#19332) - \[ENHANCEMENT] TSDB: Add `prometheus_tsdb_head_series_pending_commit_underflow_total` to report pending-sample reservation underflows. [#19470](prometheus/prometheus#19470) - \[PERF] AWS SD: Build RDS cluster labels once per cluster instead of once per instance. [#19504](prometheus/prometheus#19504) - \[PERF] AWS SD: Describe RDS instances of different clusters concurrently, bounded by `request_concurrency`. [#19506](prometheus/prometheus#19506) - \[PERF] AWS SD: Describe each ElastiCache resource once per refresh instead of twice. [#19585](prometheus/prometheus#19585) - \[PERF] Remote read: Avoid cloning labels for sampled reads when no external labels are configured. [#19503](prometheus/prometheus#19503) - \[PERF] Remote write: Reuse OTLP converter scratch state between requests. [#19388](prometheus/prometheus#19388) - \[PERF] scrape: conversion from classic to native histograms should only parse start times when enabled. [#19446](prometheus/prometheus#19446) - \[BUGFIX] PromQL: Fix `info()` enrichment for composite expressions with mixed `@`/offset references or selector-free vector branches, preventing metadata from being evaluated at an unrelated timestamp. [#19387](prometheus/prometheus#19387) - \[BUGFIX] PromQL: Fix info() enrichment when input series use different subsets of identifying labels. [#19557](prometheus/prometheus#19557) - \[BUGFIX] PromQL: Preserve metric-name dropping through the info function when delayed name removal is enabled. [#19413](prometheus/prometheus#19413) - \[BUGFIX] TSDB: Don't silently drop samples when head garbage collection removes a series while it is being appended to. [#19272](prometheus/prometheus#19272) - \[BUGFIX] TSDB: Keep series with uncommitted samples during selected- and stale-series compaction, including when appenders overlap. [#19470](prometheus/prometheus#19470) - \[BUGFIX] TSDB: Do not retain head series after a synthetic start-timestamp zero sample is rejected. [#19470](prometheus/prometheus#19470) - \[BUGFIX] TSDB: Prevent query panics during series eviction after WAL replay. [#19664](prometheus/prometheus#19664) - \[BUGFIX] TSDB: fix potential deadlock between mmapSeriesChunks and gcSeries. [#19460](prometheus/prometheus#19460) - \[BUGFIX] TSDB: fix default block reload interval for custom options. [#19368](prometheus/prometheus#19368) - \[BUGFIX] AWS SD: Do not crash on serverless MSK clusters or MSK clusters without Open Monitoring. [#19194](prometheus/prometheus#19194) - \[BUGFIX] AWS SD: Do not panic when the ElastiCache API omits optional fields of a serverless cache or cache cluster. [#19435](prometheus/prometheus#19435) - \[BUGFIX] AWS SD: Reject non-positive `request_concurrency` instead of hanging service discovery indefinitely. [#19524](prometheus/prometheus#19524) - \[BUGFIX] Discovery/AWS: Avoid a panic when discovering standalone ECS tasks with custom task groups. [#19302](prometheus/prometheus#19302) - \[BUGFIX] Discovery: Do not panic in AWS Lightsail service discovery when an instance is missing optional fields such as availability zone, blueprint, bundle, name, state or support code. [#19324](prometheus/prometheus#19324) - \[BUGFIX] Discovery: delete the stale `prometheus_sd_last_update_timestamp_seconds` series for a config that is removed on reload. [#19131](prometheus/prometheus#19131) - \[BUGFIX] HTTP: Avoid truncating compressed responses when handlers set Content-Length. [#19661](prometheus/prometheus#19661) - \[BUGFIX] IONOS SD: Do not panic when the API response omits the server, NIC or volume collections, or a server's properties. [#19438](prometheus/prometheus#19438) - \[BUGFIX] Metadata will not affect the number of Remote Write v2 shards. [#19218](prometheus/prometheus#19218) - \[BUGFIX] Mixins: Fix label mismatches that prevented PrometheusHAGroupNotIngestingSamples and PrometheusHAGroupCrashlooping from firing. [#19444](prometheus/prometheus#19444) - \[BUGFIX] Native histograms: `DetectReset` no longer misses a counter reset when a populated bucket behind an empty one disappears, which could make histogram `rate()`/`increase()` undercount. [#19367](prometheus/prometheus#19367) - \[BUGFIX] Never skip histogram buckets for histogram\_stddev and histogram\_stdvar functions. [#19521](prometheus/prometheus#19521) - \[BUGFIX] OTLP: Do not abort an entire OTLP payload ingestion if one metric has no datapoints. [#19343](prometheus/prometheus#19343) - \[BUGFIX] PromQL: Fix FastRegexMatcher false-positive match when a capturing group is directly adjacent to a literal (e.g. `.*\|(foo)\|.*`). [#19516](prometheus/prometheus#19516) - \[BUGFIX] PromQL: Fix a panic in range selectors using the experimental `anchored` or `smoothed` modifier when the selected series has no samples inside the query window, for example a query evaluated inside a scrape gap. [#19431](prometheus/prometheus#19431) - \[BUGFIX] PromQL: Fix empty results when a subquery with `@` is used as the matrix argument of a call that is not step-invariant (for example `quantile_over_time(scalar(x), metric[...:...] @ T)`). [#19187](prometheus/prometheus#19187) - \[BUGFIX] PromQL: Make the "found duplicate series for the match group" many-to-many matching error message deterministic by sorting the two duplicate labels. [#18810](prometheus/prometheus#18810) - \[BUGFIX] PromQL: Preserve parentheses around duration literals on Expr.String() round-trip. [#19403](prometheus/prometheus#19403) - \[BUGFIX] PromQL: Reject duration-expression offsets and `@ start()` / `@ end()` before range selectors, matching the existing rejection of literal offsets and `@ <timestamp>`. [#19406](prometheus/prometheus#19406) - \[BUGFIX] PromQL: Report the position of the histogram argument rather than of a scalar argument in the native histogram NaN observation annotations of `histogram_quantile` and `histogram_fraction`. [#19330](prometheus/prometheus#19330) - \[BUGFIX] PromQL: info() now applies the @ modifier/offset when evaluating the info series, so info(v @ T) enriches as of T consistently instead of depending on the query start/eval time. [#19266](prometheus/prometheus#19266) - \[BUGFIX] Rules: Fix a panic when a rule manager created without a logger loads a rule file containing multiple YAML documents. [#19433](prometheus/prometheus#19433) - \[BUGFIX] Scrape: Do not append a stale marker for a series that is still exposed when the storage returns a new series reference for it. [#19328](prometheus/prometheus#19328) - \[BUGFIX] Scrape: JSON log formatter correctly format scrape target info. [#19472](prometheus/prometheus#19472) - \[BUGFIX] TSDB: Fix in-order chunk ID overflow by wrapping head chunk IDs modulo 2^23 so they never collide with the out-of-order flag bit. [#19450](prometheus/prometheus#19450) - \[BUGFIX] TSDB: Fix out-of-order chunk ID overflow by wrapping `firstOOOChunkID` modulo 2^23 instead of growing unbounded. [#19216](prometheus/prometheus#19216) - \[BUGFIX] UI: Remove an extraneous X-axis tick mark in the native histogram chart when using the "linear" display mode. [#19326](prometheus/prometheus#19326) - \[BUGFIX] discovery/aws: Avoid a panic when an ElastiCache ARN is missing its resource ID. [#19333](prometheus/prometheus#19333) - \[BUGFIX] discovery/aws: Do not panic on MSK clusters whose optional API fields are absent. [#19584](prometheus/prometheus#19584) - \[BUGFIX] discovery/aws: Do not panic when the EC2 API omits optional instance fields. [#19512](prometheus/prometheus#19512) - \[BUGFIX] discovery/aws: Don't panic on ECS tasks with absent optional fields. [#19396](prometheus/prometheus#19396) - \[BUGFIX] discovery/aws: MSK Optional Custom Configuration Fields [#19422](prometheus/prometheus#19422). [#19422](prometheus/prometheus#19422) - \[BUGFIX] discovery/ionos: Fix panic when the IONOS API omits optional server fields. [#19418](prometheus/prometheus#19418) - \[BUGFIX] discovery/kubernetes: Populate `__meta_kubernetes_service_loadbalancer_ip` from `status.loadBalancer.ingress`, falling back to deprecated `spec.loadBalancerIP`. [#19404](prometheus/prometheus#19404) - \[BUGFIX] histogram: Fix Compact moving buckets to wrong indices, and producing negative bucket counts for integer histograms, when more than one span is merged in the same pass. [#19312](prometheus/prometheus#19312) - \[BUGFIX] promtool: Fixed `tsdb dump` silently dropping native histogram samples. [#18051](prometheus/prometheus#18051) - \[BUGFIX] scrape: fix data race in `Manager.TargetsDroppedCounts` to avoid miscounting dropped targets. [#19304](prometheus/prometheus#19304) - \[BUGFIX] scrape: fix nil histogram when native and classic histograms are mixed in one metric family. [#19452](prometheus/prometheus#19452) - \[BUGFIX] TSDB: Fix WAL and GC log messages to emit human-readable duration strings instead of nanosecond integers. [#19307](prometheus/prometheus#19307) - \[BUGFIX] TSDB: Avoid WAL corruption after a failed WAL write in Agent mode. [#19700](prometheus/prometheus#19700) - \[BUGFIX] Agent: Ignore unknown WAL record types, to help users rolling back. [#19814](prometheus/prometheus#19814) </details> --- ### Configuration 📅 **Schedule**: (in timezone Europe/Paris) - Branch creation - At any time (no schedule defined) - Automerge - At any time (no schedule defined) 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Mend Renovate CLI](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.erwanleboucher.dev/eleboucher/homelab/pulls/2199

perfloop-agent requested review from a team, alexgreenbank, bwplotka, cstyan and tomwilkie as code owners August 22, 2026 14:10

perfloop-agent added 2 commits August 22, 2026 14:44

storage/remote: benchmark sampled reads without external labels

e1c2ce1

Signed-off-by: Perfloop Agent <[email protected]>

perf(storage/remote): avoid cloning labels without external labels

cf5543c

Signed-off-by: Perfloop Agent <[email protected]>

perfloop-agent force-pushed the perfloop-pr-open-68jh6z0xvn branch from 46ebec8 to cf5543c Compare August 22, 2026 17:45

aknuds1 approved these changes Aug 24, 2026

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aknuds1 merged commit e4334de into prometheus:main Aug 24, 2026
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[storage/remote] Group TestSampledReadEndpoint test cases #19513

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tsenart mentioned this pull request Sep 24, 2026

fix: preserve order for chunked address-filtered logs joshstevens19/rindexer#474

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[IMPROVED] Avoid subject scratch allocation for unmapped deliveries nats-io/nats-server#8696

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perf(rowid): skip delete-mask work for delete-free scans datafusion-contrib/datafusion-ducklake#368

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Fix slot memory accounting after IDMP expiry redis/redis#15887

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[BUG](wal3): Wake pin capacity waiters chroma-core/chroma#7904

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Aggregate v2 subscription updates in place clockworklabs/SpacetimeDB#6136

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Resolver: fixed waiting requests stuck on unusable responses nginx/nginx#1983

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leanchecker crashes on legacy targets with obsolete module sidecars leanprover/lean4#16466

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unicode/norm: reset stream-safe state before appending golang/text#79

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perf(storage/remote): avoid cloning labels without external labels - #19503

perf(storage/remote): avoid cloning labels without external labels#19503
aknuds1 merged 2 commits into
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perfloop-agent commented Aug 22, 2026 •

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