# Prometheus v3.14.0-rc.0 — 3.14.0-rc.0 / 2026-08-06

- Product: Prometheus (https://whatsnew.fyi/product/prometheus)
- Vendor: Prometheus
- Date: 2026-08-11
- Version: v3.14.0-rc.0
- Original notes: https://github.com/prometheus/prometheus/releases/tag/v3.14.0-rc.0
- Permalink: https://whatsnew.fyi/product/prometheus/releases/v3.14.0-rc.0
- Labels: Pre-release

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **deprecated** — Deprecate the `stats` query parameter of `/api/v1/query` and `/api/v1/query_range` for values other than `true` and `all`; other values will be rejected in the next major release
- **changed** — API `/api/v1/status/config` now correctly shows `separator: ""` and `replacement: ""` in relabel configs when explicitly set to empty
- **changed** — Discovery/Hetzner: Drop the `__meta_hetzner_datacenter` label for `hcloud` targets following its removal from the Hetzner Cloud API
- **changed** — PromQL: Enable duration expressions by default; the `promql-duration-expr` feature flag is now a no-op
- **changed** — PromQL: Promote `first_over_time` to stable and no longer require the `promql-experimental-functions` feature flag
- **added** — Discovery: Add Oracle Cloud Infrastructure compute service discovery (`oci_sd_configs`)
- **added** — PromQL: Add experimental `start_timestamp(instant-vector)` function returning the start timestamp of each sample in the given vector
- **added** — PromQL: Allow `rate()` and `increase()` to use start timestamps as an alternative for rate extrapolation
- **added** — TSDB: Add experimental support for encoding start timestamps in histograms and float histograms
- **changed** — OTLP: Emit a warning when OTLP attribute names collide into the same Prometheus label after sanitization and expose the `prometheus_api_otlp_translation_warnings_total` counter
- **added** — Promtool: Add `--remote-write.path` flag to `push metrics` for backends that use a non-default remote-write endpoint
- **changed** — Remote write: Forward histogram start timestamps in the remote write V2 protocol
- **added** — TSDB: Add `prometheus_tsdb_head_native_histogram_series` and `prometheus_tsdb_head_native_histogram_buckets` gauges tracking native histogram series and buckets in the head
- **changed** — UI: Add syntax highlighting, autocompletion, and linting for PromQL duration expressions in range selectors and subqueries
- **added** — UI: Add copy button next to rule names on the Rules and Alerts pages
- **changed** — UI: Improve rule group title contrast on the Rules page
- **fixed** — Speed up regex label matchers matching a set of literal values
- **changed** — Remote read: Improve remote read throughput by removing unnecessary per-write flushing
- **fixed** — Scrape: Parse text and OpenMetrics formats without recursion, preventing stack overflow from deeply nested or malicious exposition input
- **fixed** — Scrape: Reduce native histogram scrape parsing allocations by approximately 49%

- [CHANGE] API: Deprecate the `stats` query parameter of `/api/v1/query` and `/api/v1/query_range` for values other than `true` and `all`. Other values still enable basic statistics but now return a deprecation warning; they will be rejected in the next major release. #19124
- [CHANGE] API: `/api/v1/status/config` now correctly shows `separator: ""` and `replacement: ""` in relabel configs when explicitly set to empty, instead of omitting them. #18653
- [CHANGE] Discovery/Hetzner: Drop the `__meta_hetzner_datacenter` label for `hcloud` targets, following its removal from the Hetzner Cloud API. #19269
- [CHANGE] PromQL: Enable duration expressions by default. The `promql-duration-expr` feature flag is now a no-op. #19033
- [CHANGE] PromQL: Promote `first_over_time` to stable. It no longer requires the `promql-experimental-functions` feature flag. #19093
- [FEATURE] Discovery: Add Oracle Cloud Infrastructure compute service discovery (`oci_sd_configs`). #18919
- [FEATURE] PromQL: Add experimental `start_timestamp(instant-vector)` function returning the start timestamp of each sample in the given vector. Requires the `use-start-timestamps` feature flag. #19089
- [FEATURE] PromQL: Allow `rate()` and `increase()` to use start timestamps as an alternative for rate extrapolation. Hidden behind the `use-start-timestamps` feature flag. #18619
- [FEATURE] TSDB: Add experimental support for encoding start timestamps in histograms and float histograms. Hidden behind the `histograms-st-encoding` feature flag. #18609
- [ENHANCEMENT] OTLP: Emit a warning when OTLP attribute names collide into the same Prometheus label after sanitization (e.g. `k8s.pod.name` and `k8s_pod_name` both become `k8s_pod_name`), and expose the `prometheus_api_otlp_translation_warnings_total` counter labelled by `category` to track such warnings. #18957
- [ENHANCEMENT] Promtool: Add `--remote-write.path` flag to `push metrics` for backends that use a non-default remote-write endpoint. #19086
- [ENHANCEMENT] Remote write: Forward histogram start timestamps in the remote write V2 protocol. #18903
- [ENHANCEMENT] TSDB: Add `prometheus_tsdb_head_native_histogram_series` and `prometheus_tsdb_head_native_histogram_buckets` gauges tracking the number of native histogram series and buckets in the head. #19170
- [ENHANCEMENT] UI: Add syntax highlighting, autocompletion, and linting for PromQL duration expressions (`step()`, `range()`, `min_of()`, `max_of()`) in range selectors and subqueries. #18625
- [ENHANCEMENT] UI: Add copy button next to rule names on the Rules and Alerts pages. #18706
- [ENHANCEMENT] UI: Improve rule group title contrast on the Rules page. #19181
- [PERF] Speed up regex label matchers matching a set of literal values (e.g. `{job=~"foo|bar|baz"}`). #18833
- [PERF] Remote read: Improve remote read throughput by removing unnecessary per-write flushing. #18470
- [PERF] Scrape: Parse text and OpenMetrics formats without recursion, preventing stack overflow from deeply nested or malicious exposition input. #19143
- [PERF] Scrape: Reduce native histogram scrape parsing allocations by ~49%. #19282
- [PERF] TSDB: Speed up queries on series with many in-memory chunks. #18300
- [BUGFIX] Alerting: Fix 100% CPU usage on shutdown that could delay graceful shutdown and trigger timeout-based kills. #17859
- [BUGFIX] Discovery/AWS: Stop `promtool check config` from making AWS metadata service (IMDS) network calls when the `region` field is omitted in EC2, ECS, RDS, MSK, ElastiCache, and Lightsail service discovery configs. #19037
- [BUGFIX] Discovery/Docker: Set a request timeout for `docker_sd` and `dockerswarm_sd` on `unix`, `npipe`, and `tcp` hosts. Previously an unresponsive daemon could freeze discovery indefinitely, silently pinning targets to a stale snapshot. #19237
- [BUGFIX] Discovery/Docker: Fix panic in Docker Swarm service discovery when a service runs as a plugin or network-attachment. #19102
- [BUGFIX] Discovery/Docker: Fix discov

_[Truncated at 4000 characters — full notes: https://github.com/prometheus/prometheus/releases/tag/v3.14.0-rc.0]_