config: validate remote_write queue_config fields by Sanchit2662 · Pull Request #18209 · prometheus/prometheus

Sanchit2662 · 2026-03-01T11:31:54Z

Summary

While working with remote write configurations, I noticed that queue_config parameters had zero validation. This meant users could accidentally set max_samples_per_send: 0 (or other invalid combinations) and Prometheus would accept the config silently—only to panic at runtime with an integer divide-by-zero error when the queue manager started.

The panic happens in newQueue() when calculating capacity / batchSize with batchSize=0. Beyond the crash, other misconfigurations like min_shards > max_shards or max_backoff < min_backoff were also silently accepted, leading to undefined runtime behavior.

This PR adds proper validation to catch these issues at config load time.

Fix

Added QueueConfig.Validate() method in config/config.go that checks:

All numeric fields are positive (max_shards, min_shards, max_samples_per_send, capacity)
min_shards ≤ max_shards
max_backoff ≥ min_backoff

The validation is called from RemoteWriteConfig.UnmarshalYAML() so invalid configs fail fast during startup.

Key changes:

config/config.go — Added validation method (~20 LOC):

func (c *QueueConfig) Validate() error {
    if c.MaxSamplesPerSend <= 0 {
        return errors.New("remote write queue max_samples_per_send must be positive")
    }
    if c.Capacity <= 0 {
        return errors.New("remote write queue capacity must be positive")
    }
    // ... additional checks for shards and backoff
    if c.MinShards > c.MaxShards {
        return errors.New("remote write queue min_shards must not be greater than max_shards")
    }
    return nil
}

Also added 3 test cases in config/config_test.go and corresponding bad config YAML files in config/testdata/ covering each validation path.

Does this PR introduce a user-facing change?

[BUGFIX] Config: Validate remote_write queue_config fields at load time to prevent runtime panic and silent misconfiguration.

Signed-off-by: Sanchit2662 <sanchit2662@gmail.com>

Sanchit2662 · 2026-03-01T12:32:25Z

Hi @grobinson-grafana @bwplotka , Adds missing queue_config validation to catch misconfigurations (like max_samples_per_send: 0) at load time instead of panicking at runtime. Happy to adjust if needed, thanks!

bwplotka

Looks reasonable to me, thanks!

Copilot

Pull request overview

This PR adds validation to the remote_write queue_config block in Prometheus's configuration system. When a user provides invalid values (e.g., max_samples_per_send: 0, min_shards > max_shards, or max_backoff < min_backoff), the configuration is now rejected at load time with a descriptive error rather than silently accepted and causing a runtime panic or undefined behavior.

Changes:

Added a QueueConfig.Validate() method in config/config.go that checks positivity of key fields and validates field relationships
Called QueueConfig.Validate() from RemoteWriteConfig.UnmarshalYAML to enforce validation at config load time
Added 3 bad YAML test fixtures and corresponding entries in the expectedErrors table in config_test.go

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
`config/config.go`	Adds the `QueueConfig.Validate()` method and integrates it into `UnmarshalYAML`
`config/config_test.go`	Adds 3 error test cases for the new validation rules
`config/testdata/remote_write_queue_max_samples_per_send_zero.bad.yml`	Bad config fixture: `max_samples_per_send: 0`
`config/testdata/remote_write_queue_min_shards_greater_than_max.bad.yml`	Bad config fixture: `min_shards > max_shards`
`config/testdata/remote_write_queue_max_backoff_less_than_min.bad.yml`	Bad config fixture: `max_backoff < min_backoff`

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Signed-off-by: Sanchit2662 <sanchit2662@gmail.com>

Sanchit2662 · 2026-03-06T14:52:05Z

Thanks for the review! @bwplotka ,
I have made the required changes , tell me if you need some changes.

Sanchit2662 · 2026-03-07T23:01:16Z

@bwplotka , shall i modify anything on this pr?

Sanchit2662 · 2026-04-22T12:42:06Z

hey @kakkoyun @roidelapluie @SuperQ , just wanted to ping on this, no rush at all, let me know if anything else needs to be changed!

roidelapluie · 2026-04-25T10:31:53Z

I will have a look.

roidelapluie · 2026-05-04T13:49:48Z

Thanks!

Sanchit2662 · 2026-05-04T13:57:00Z

Thanku for the review
@roidelapluie

…➔ v3.12.0) (#730) This PR contains the following updates: | Package | Update | Change | |---|---|---| | [quay.io/prometheus/prometheus](https://github.com/prometheus/prometheus) | minor | `v3.11.3` → `v3.12.0` | --- ### Release Notes <details> <summary>prometheus/prometheus (quay.io/prometheus/prometheus)</summary> ### [`v3.12.0`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0): 3.12.0 / 2026-05-28 [Compare Source](prometheus/prometheus@v3.11.3...v3.12.0) - \[SECURITY] Remote-write: Reject snappy-compressed requests whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate(), and `increase()`calculations, behind a feature flag`use-start-timestamps`. Doesn't work together with extended range selectors `anchored`and`smoothed\`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487) </details> --- ### Configuration 📅 **Schedule**: 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 these updates again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.erwanleboucher.dev/eleboucher/homelab/pulls/730

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

@hibrian827

##### [\`v3.12.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.12.0) This release contains security fixes, new features (especially around PromQL and Service Discovery), performance improvements in TSDB, Start Timestamp improvements and numerous bug fixes. Thanks to all contributors! #### Key Highlights - **Security**: Two security vulnerabilities have been addressed: a denial of service in remote-write (snappy decompression limit) and a secret exposure leak in STACKIT service discovery. - **PromQL & Metadata**: Several features and bug fixes related to the experimental "start timestamps" support, including updates to `rate()`, `irate()`, `increase()`, and `resets()`. New experimental functions `start()`, `end()`, `range()`, and `step()` are introduced. - **TSDB Performance**: Optimizations in head chunk lookup (constant time) and mmap operations to reduce CPU usage. - **Service Discovery**: Added support for DigitalOcean Managed Databases and Outscale VM, along with improvements to AWS SD (IPv6 support for EC2, external ID support). - **UI**: Added a web interface for deleting time series and cleaning tombstones. #### Changelog - \[SECURITY] Remote: Reject snappy-compressed received requests via Remote Write whose declared decoded length exceeds the 32MB. Thanks to [@hibrian827](https://github.com/hibrian827) for reporting it. [#18642](prometheus/prometheus#18642) - \[SECURITY] STACKIT SD: Fix secrets being exposed in plaintext via `/-/config` endpoint. Thanks to [@August829](https://github.com/August829) and [@Phaxma](https://github.com/Phaxma) for reporting. GHSA-39j6-789q-qxvh [#18649](prometheus/prometheus#18649) - \[CHANGE] TSDB/Agent: Adds Start Timestamp field to all WAL Histogram samples in memory; used `st-storage` flag is enabled. [#18221](prometheus/prometheus#18221) - \[FEATURE] API: Add `/api/v1/status/self_metrics` endpoint returning the current state of the Prometheus server's own metrics about itself as JSON. [#18411](prometheus/prometheus#18411) - \[FEATURE] Discovery: Add DigitalOcean Managed Databases service discovery [#18287](prometheus/prometheus#18287) - \[FEATURE] Prometheus: Add support for the aix/ppc64 compilation target [#18321](prometheus/prometheus#18321) - \[FEATURE] Discovery: Add Outscale VM service discovery (`outscale_sd_configs`) for discovering scrape targets from the Outscale Cloud API. [#18139](prometheus/prometheus#18139) - \[FEATURE] PromQL: Emit a warning when `sort`, `sort_by_label` or `sort_by_label_desc` is used within range (matrix) queries, as these functions do not have effect in that context. [#18498](prometheus/prometheus#18498) - \[FEATURE] PromQL: Add `start()`, `end()`, `range()`, and `step()` experimental functions [#17877](prometheus/prometheus#17877) - \[FEATURE] PromQL: Update `resets()` function to consider start timestamp resets. Hidden behind `use-start-timestamps` feature flag. [#18627](prometheus/prometheus#18627) - \[FEATURE] Prometheus: Promote auto-reload-config as stable [#18620](prometheus/prometheus#18620) - \[FEATURE] TSDB/Agent: Add `CheckpointFromInMemorySeries` option to `agent.DB` that enables checkpoint based on in-memory series. [#17948](prometheus/prometheus#17948) - \[FEATURE] UI: Add a web interface for deleting time series and cleaning tombstones, accessible from the Status menu. [#18390](prometheus/prometheus#18390) - \[FEATURE] PromQL: Use start timestamps for `rate()`, `irate()`, and `increase()` calculations, behind a feature flag `use-start-timestamps`. Doesn't work together with extended range selectors `anchored` and `smoothed`. [#18344](prometheus/prometheus#18344) - \[FEATURE] Scrape: Added a feature flag `st-synthesis` which synthesizes unknown STs for scraped cumulative metrics. Useful when Remote Writing 2.0 with delta or Otel-based backends. [#18279](prometheus/prometheus#18279) - \[FEATURE] promqltest: support `@st` annotation in `load` blocks to specify per-sample start timestamps. [#18360](prometheus/prometheus#18360) - \[ENHANCEMENT] API: reject concurrent fgprof profiles. [#18651](prometheus/prometheus#18651) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field to ECS/MSK/RDS/Elasticache. [#18579](prometheus/prometheus#18579) - \[ENHANCEMENT] AWS SD: Add optional `external_id` field. [#17171](prometheus/prometheus#17171) - \[ENHANCEMENT] Discovery: Propagate SD target updates faster by introducing dynamic backoff interval instead of static 5s interval for throttling. [#18187](prometheus/prometheus#18187) - \[ENHANCEMENT] Promtool: Add `--header` flag to `query instant` command, matching existing `query range` behaviour. [#18418](prometheus/prometheus#18418) - \[ENHANCEMENT]: AWS SD: Allows EC2 service discovery to discover IPv6 addresses to communicate with target endpoints. The private IPv4 address remains the default when both IPv4 and IPv6 addresses are present. [#16088](prometheus/prometheus#16088) - \[PERF] TSDB: Make head chunk lookup in range queries constant time instead of quadratic time [#18302](prometheus/prometheus#18302) - \[PERF] TSDB: Skip entire stripes in mmapHeadChunks when no series need mmapping, reducing CPU utilization significantly at production-relevant scales. [#18541](prometheus/prometheus#18541) - \[PERF] TSDB: Skip clean series during periodic head chunk mmap using cached head chunk count [#18272](prometheus/prometheus#18272) - \[PERF] PromQL: Address FloatHistogram.KahanAdd performance regression on Go 1.26. [#18568](prometheus/prometheus#18568) - \[BUGFIX] PromQL: Fix `info()` function incorrectly handling negated `__name__` matchers [#17932](prometheus/prometheus#17932) - \[BUGFIX] API: Return duration expressions in `/parse_ast`. [#18624](prometheus/prometheus#18624) - \[BUGFIX] API: correctly document formats accepted for duration query request parameters (step, timeout and lookback delta) in OpenAPI spec [#18305](prometheus/prometheus#18305) - \[BUGFIX] Scrape: AppenderV2 now tracks staleness even when OOO/duplicate series errors happen similar to AppenderV1 [#18567](prometheus/prometheus#18567) - \[BUGFIX] Config: Validate remote\_write queue\_config fields at load time to prevent runtime panic and silent misconfiguration. [#18209](prometheus/prometheus#18209) - \[BUGFIX] Discovery/Consul: Add `health_filter` for Health API filtering, fixing breakage when using Catalog-only fields like `ServiceTags` in `filter`. [#18479](prometheus/prometheus#18479) [#18499](prometheus/prometheus#18499) - \[BUGFIX] OTLP: limit decompressed body size for gzip-encoded OTLP write requests. [#18408](prometheus/prometheus#18408) - \[BUGFIX] PromQL: Fix `smoothed` rate/increase returning zero instead of no result when all data falls strictly after the query range. [#18523](prometheus/prometheus#18523) - \[BUGFIX] PromQL: Fix metric name not being dropped when last\_over\_time or first\_over\_time is applied to subqueries containing name-dropping functions like abs(). [#18409](prometheus/prometheus#18409) - \[BUGFIX] PromQL: Fix missing warning when mixing exponential and custom-bucket histograms in stats queries. [#18660](prometheus/prometheus#18660) - \[BUGFIX] PromQL: Fix parsing of `range()` keyword in duration expressions such as `foo[5m+range()]`. [#18623](prometheus/prometheus#18623) - \[BUGFIX] PromQL: Fix smoothed vector selector returning no results in binary operations when the `@` modifier is used. [#18531](prometheus/prometheus#18531) - \[BUGFIX] PromQL: Reject NaN, infinite, and out-of-range duration expressions instead of silently producing an out-of-range time.Duration. [#18639](prometheus/prometheus#18639) - \[BUGFIX] Scrape: Fix panic when scraping malformed native histograms. [#18414](prometheus/prometheus#18414) - \[BUGFIX] Scrape: fix panic when scraping a target exposing a summary with no quantiles via the protobuf format. [#18382](prometheus/prometheus#18382) - \[BUGFIX] Scrape: fix scrape failure log file occasionally not applied after a configuration reload. [#18421](prometheus/prometheus#18421) - \[BUGFIX] TSDB: Allow retention percentage with new data path. [#18628](prometheus/prometheus#18628) - \[BUGFIX] TSDB: Preserve decimal precision in percentage-based retention [#18374](prometheus/prometheus#18374) - \[BUGFIX] TSDB: fix prometheus\_tsdb\_head\_chunks going negative after WAL replay [#18401](prometheus/prometheus#18401) - \[BUGFIX] TSDB: panic with native histograms during query of overlapping chunks. [#18692](prometheus/prometheus#18692) - \[BUGFIX] Tracing: fix startup failure for insecure OTLP HTTP tracing [#18469](prometheus/prometheus#18469) - \[BUGFIX] UI: Escape label values offered by PromQL autocomplete. [#18658](prometheus/prometheus#18658) - \[BUGFIX] UI: Improve Y-axis tick label precision for graph values over small ranges. [#18682](prometheus/prometheus#18682) - \[BUGFIX] `prometheus_sd_refresh*` and `prometheus_sd_discovered_targets` metrics for specific scrape jobs are deleted when the scrape job is removed. [#17614](prometheus/prometheus#17614) - \[BUGFIX] Remote: fixed validation for received RW2 requests when parsing metadata unit symbols. This fixes a case when request would cause (recovered) handler panic. [#18641](prometheus/prometheus#18641) - \[BUGFIX] TSDB/Agent: fix race in agent appender where concurrent appends for the same label set could produce duplicate in-memory series and duplicate WAL records. [#18292](prometheus/prometheus#18292) - \[BUGFIX] Config: Update `--enable-feature` flag description and sort feature names. [#18487](prometheus/prometheus#18487)

config: validate remote_write queue_config fields

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Signed-off-by: Sanchit2662 <sanchit2662@gmail.com>

Sanchit2662 requested a review from a team as a code owner March 1, 2026 11:31

Sanchit2662 requested a review from grobinson-grafana March 1, 2026 11:31

bwplotka requested a review from Copilot March 4, 2026 06:50

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Comment thread config/testdata/remote_write_queue_max_backoff_less_than_min.bad.yml

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Comment thread config/config.go

config: add missing queue_config validation test cases

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Signed-off-by: Sanchit2662 <sanchit2662@gmail.com>

Sanchit2662 requested a review from bwplotka March 4, 2026 10:51

roidelapluie approved these changes May 4, 2026

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roidelapluie merged commit 9c23509 into prometheus:main May 4, 2026
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config: validate remote_write queue_config fields#18209

config: validate remote_write queue_config fields#18209
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Sanchit2662:validate-remote-write-queue-config

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