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UI: Fix broken Y axis after graph page reload#17869

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Nexucis merged 2 commits intomainfrom
fix-y-axis-min-encoding
Jan 16, 2026
Merged

UI: Fix broken Y axis after graph page reload#17869
Nexucis merged 2 commits intomainfrom
fix-y-axis-min-encoding

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@juliusv juliusv commented Jan 16, 2026

The new y_axis_min setting was always encoded into the URL, even if its value was null (in which case it would be set to an empty string parameter). On the decoding side, this wasn't taken into account correctly, and we tried to parse the empty string as a float, causing completely broken graphs showing nothing after reloading the graph page with such URL parameters.

I'm doing two things now:

  • For the future, only encode the Y axis min into the URL if it's set at all, similar as we do for the end_input and moment_input fields.
  • On the decoding side, accommodate people (at least for now) who already saved some links with the empty y_axis_min parameter by treating an empty string as null instead of a number.

Does this PR introduce a user-facing change?

[BUGFIX] UI: Fix broken graph display after page reload, due to broken Y axis min encoding/decoding.

The new `y_axis_min` setting was always encoded into the URL, even if its value
was `null` (in which case it would be set to an empty string parameter). On the
decoding side, this wasn't taken into account correctly, and we tried to parse
the empty string as a float, causing completely broken graphs showing nothing
after reloading the graph page with such URL parameters.

I'm doing two things now:

* For the future, only encode the Y axis min into the URL if it's set at all,
  similar as we do for the `end_input` and `moment_input` fields.
* On the decoding side, accommodate people (at least for now) who already saved
  some links with the empty `y_axis_min` parameter by treating an empty string
  as `null` instead of a number.

Signed-off-by: Julius Volz <[email protected]>
@juliusv juliusv requested a review from Nexucis January 16, 2026 09:18
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juliusv commented Jan 16, 2026

Disclaimer: I threw in some Claude-one-shot-generated unit tests as well for good measure - they are maybe a bit overly detailed, but they do make sense to me.

@Nexucis Nexucis enabled auto-merge (squash) January 16, 2026 09:37
@Nexucis Nexucis merged commit ded3a8c into main Jan 16, 2026
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@Nexucis Nexucis deleted the fix-y-axis-min-encoding branch January 16, 2026 09:50
renovate bot added a commit to sdwilsh/ansible-playbooks that referenced this pull request Mar 12, 2026
##### [\`v3.10.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.10.0)

Prometheus now offers a distroless Docker image variant alongside the default
busybox image. The distroless variant provides enhanced security with a minimal
base image, uses UID/GID 65532 (nonroot) instead of nobody, and removes the
VOLUME declaration. Both variants are available with `-busybox` and `-distroless`
tag suffixes (e.g., `prom/prometheus:latest-busybox`, `prom/prometheus:latest-distroless`).
The busybox image remains the default with no suffix for backwards compatibility
(e.g., `prom/prometheus:latest` points to the busybox variant).

For users migrating existing **named** volumes from the busybox image to the distroless variant, the ownership can be adjusted with:

```
docker run --rm -v prometheus-data:/prometheus alpine chown -R 65532:65532 /prometheus
```

Then, the container can be started with the old volume with:

```
docker run -v prometheus-data:/prometheus prom/prometheus:latest-distroless
```

User migrating from bind mounts might need to ajust permissions too, depending on their setup.

- \[CHANGE] Alerting: Add `alertmanager` dimension to following metrics: `prometheus_notifications_dropped_total`, `prometheus_notifications_queue_capacity`, `prometheus_notifications_queue_length`. [#16355](prometheus/prometheus#16355)
- \[CHANGE] UI: Hide expanded alert annotations by default, enabling more information density on the `/alerts` page. [#17611](prometheus/prometheus#17611)
- \[FEATURE] AWS SD: Add MSK Role. [#17600](prometheus/prometheus#17600)
- \[FEATURE] PromQL: Add `fill()` / `fill_left()` / `fill_right()` binop modifiers for specifying default values for missing series. [#17644](prometheus/prometheus#17644)
- \[FEATURE] Web: Add OpenAPI 3.2 specification for the HTTP API at `/api/v1/openapi.yaml`. [#17825](prometheus/prometheus#17825)
- \[FEATURE] Dockerfile: Add distroless image variant using UID/GID 65532 and no VOLUME declaration. Busybox image remains default. [#17876](prometheus/prometheus#17876)
- \[FEATURE] Web: Add on-demand wall time profiling under `<URL>/debug/pprof/fgprof`. [#18027](prometheus/prometheus#18027)
- \[ENHANCEMENT] PromQL: Add more detail to histogram quantile monotonicity info annotations. [#15578](prometheus/prometheus#15578)
- \[ENHANCEMENT] Alerting: Independent alertmanager sendloops. [#16355](prometheus/prometheus#16355)
- \[ENHANCEMENT] TSDB: Experimental support for early compaction of stale series in the memory with configurable threshold `stale_series_compaction_threshold` in the config file. [#16929](prometheus/prometheus#16929)
- \[ENHANCEMENT] Service Discovery: Service discoveries are now removable from the Prometheus binary through the Go build tag `remove_all_sd` and individual service discoveries can be re-added with the build tags `enable_<sd name>_sd`. Users can build a custom Prometheus with only the necessary SDs for a smaller binary size. [#17736](prometheus/prometheus#17736)
- \[ENHANCEMENT] Promtool: Support promql syntax features `promql-duration-expr` and `promql-extended-range-selectors`. [#17926](prometheus/prometheus#17926)
- \[PERF] PromQL: Avoid unnecessary label extraction in PromQL functions. [#17676](prometheus/prometheus#17676)
- \[PERF] PromQL: Improve performance of regex matchers like `.*-.*-.*`. [#17707](prometheus/prometheus#17707)
- \[PERF] OTLP: Add label caching for OTLP-to-Prometheus conversion to reduce allocations and improve latency. [#17860](prometheus/prometheus#17860)
- \[PERF] API: Compute `/api/v1/targets/relabel_steps` in a single pass instead of re-running relabeling for each prefix. [#17969](prometheus/prometheus#17969)
- \[PERF] tsdb: Optimize LabelValues intersection performance for matchers. [#18069](prometheus/prometheus#18069)
- \[BUGFIX] PromQL: Prevent query strings containing only UTF-8 continuation bytes from crashing Prometheus. [#17735](prometheus/prometheus#17735)
- \[BUGFIX] Web: Fix missing `X-Prometheus-Stopping` header for `/-/ready` endpoint in `NotReady` state. [#17795](prometheus/prometheus#17795)
- \[BUGFIX] PromQL: Fix PromQL `info()` function returning empty results when filtering by a label that exists on both the input metric and `target_info`. [#17817](prometheus/prometheus#17817)
- \[BUGFIX] TSDB: Fix a bug during exemplar buffer grow/shrink that could cause exemplars to be incorrectly discarded. [#17863](prometheus/prometheus#17863)
- \[BUGFIX] UI: Fix broken graph display after page reload, due to broken Y axis min encoding/decoding. [#17869](prometheus/prometheus#17869)
- \[BUGFIX] TSDB: Fix memory leaks in buffer pools by clearing reference fields (Labels, Histogram pointers, metadata strings) before returning buffers to pools. [#17879](prometheus/prometheus#17879)
- \[BUGFIX] PromQL: info function: fix series without identifying labels not being returned. [#17898](prometheus/prometheus#17898)
- \[BUGFIX] OTLP: Filter `__name__` from OTLP attributes to prevent duplicate labels. [#17917](prometheus/prometheus#17917)
- \[BUGFIX] TSDB: Fix division by zero when computing stale series ratio with empty head. [#17952](prometheus/prometheus#17952)
- \[BUGFIX] OTLP: Fix potential silent data loss for sum metrics. [#17954](prometheus/prometheus#17954)
- \[BUGFIX] PromQL: Fix smoothed interpolation across counter resets. [#17988](prometheus/prometheus#17988)
- \[BUGFIX] PromQL: Fix panic with `@` modifier on empty ranges. [#18020](prometheus/prometheus#18020)
- \[BUGFIX] PromQL: Fix `avg_over_time` for a single native histogram. [#18058](prometheus/prometheus#18058)
renovate bot added a commit to sdwilsh/ansible-playbooks that referenced this pull request Mar 13, 2026
##### [\`v3.10.0\`](https://github.com/prometheus/prometheus/releases/tag/v3.10.0)

Prometheus now offers a distroless Docker image variant alongside the default
busybox image. The distroless variant provides enhanced security with a minimal
base image, uses UID/GID 65532 (nonroot) instead of nobody, and removes the
VOLUME declaration. Both variants are available with `-busybox` and `-distroless`
tag suffixes (e.g., `prom/prometheus:latest-busybox`, `prom/prometheus:latest-distroless`).
The busybox image remains the default with no suffix for backwards compatibility
(e.g., `prom/prometheus:latest` points to the busybox variant).

For users migrating existing **named** volumes from the busybox image to the distroless variant, the ownership can be adjusted with:

```
docker run --rm -v prometheus-data:/prometheus alpine chown -R 65532:65532 /prometheus
```

Then, the container can be started with the old volume with:

```
docker run -v prometheus-data:/prometheus prom/prometheus:latest-distroless
```

User migrating from bind mounts might need to ajust permissions too, depending on their setup.

- \[CHANGE] Alerting: Add `alertmanager` dimension to following metrics: `prometheus_notifications_dropped_total`, `prometheus_notifications_queue_capacity`, `prometheus_notifications_queue_length`. [#16355](prometheus/prometheus#16355)
- \[CHANGE] UI: Hide expanded alert annotations by default, enabling more information density on the `/alerts` page. [#17611](prometheus/prometheus#17611)
- \[FEATURE] AWS SD: Add MSK Role. [#17600](prometheus/prometheus#17600)
- \[FEATURE] PromQL: Add `fill()` / `fill_left()` / `fill_right()` binop modifiers for specifying default values for missing series. [#17644](prometheus/prometheus#17644)
- \[FEATURE] Web: Add OpenAPI 3.2 specification for the HTTP API at `/api/v1/openapi.yaml`. [#17825](prometheus/prometheus#17825)
- \[FEATURE] Dockerfile: Add distroless image variant using UID/GID 65532 and no VOLUME declaration. Busybox image remains default. [#17876](prometheus/prometheus#17876)
- \[FEATURE] Web: Add on-demand wall time profiling under `<URL>/debug/pprof/fgprof`. [#18027](prometheus/prometheus#18027)
- \[ENHANCEMENT] PromQL: Add more detail to histogram quantile monotonicity info annotations. [#15578](prometheus/prometheus#15578)
- \[ENHANCEMENT] Alerting: Independent alertmanager sendloops. [#16355](prometheus/prometheus#16355)
- \[ENHANCEMENT] TSDB: Experimental support for early compaction of stale series in the memory with configurable threshold `stale_series_compaction_threshold` in the config file. [#16929](prometheus/prometheus#16929)
- \[ENHANCEMENT] Service Discovery: Service discoveries are now removable from the Prometheus binary through the Go build tag `remove_all_sd` and individual service discoveries can be re-added with the build tags `enable_<sd name>_sd`. Users can build a custom Prometheus with only the necessary SDs for a smaller binary size. [#17736](prometheus/prometheus#17736)
- \[ENHANCEMENT] Promtool: Support promql syntax features `promql-duration-expr` and `promql-extended-range-selectors`. [#17926](prometheus/prometheus#17926)
- \[PERF] PromQL: Avoid unnecessary label extraction in PromQL functions. [#17676](prometheus/prometheus#17676)
- \[PERF] PromQL: Improve performance of regex matchers like `.*-.*-.*`. [#17707](prometheus/prometheus#17707)
- \[PERF] OTLP: Add label caching for OTLP-to-Prometheus conversion to reduce allocations and improve latency. [#17860](prometheus/prometheus#17860)
- \[PERF] API: Compute `/api/v1/targets/relabel_steps` in a single pass instead of re-running relabeling for each prefix. [#17969](prometheus/prometheus#17969)
- \[PERF] tsdb: Optimize LabelValues intersection performance for matchers. [#18069](prometheus/prometheus#18069)
- \[BUGFIX] PromQL: Prevent query strings containing only UTF-8 continuation bytes from crashing Prometheus. [#17735](prometheus/prometheus#17735)
- \[BUGFIX] Web: Fix missing `X-Prometheus-Stopping` header for `/-/ready` endpoint in `NotReady` state. [#17795](prometheus/prometheus#17795)
- \[BUGFIX] PromQL: Fix PromQL `info()` function returning empty results when filtering by a label that exists on both the input metric and `target_info`. [#17817](prometheus/prometheus#17817)
- \[BUGFIX] TSDB: Fix a bug during exemplar buffer grow/shrink that could cause exemplars to be incorrectly discarded. [#17863](prometheus/prometheus#17863)
- \[BUGFIX] UI: Fix broken graph display after page reload, due to broken Y axis min encoding/decoding. [#17869](prometheus/prometheus#17869)
- \[BUGFIX] TSDB: Fix memory leaks in buffer pools by clearing reference fields (Labels, Histogram pointers, metadata strings) before returning buffers to pools. [#17879](prometheus/prometheus#17879)
- \[BUGFIX] PromQL: info function: fix series without identifying labels not being returned. [#17898](prometheus/prometheus#17898)
- \[BUGFIX] OTLP: Filter `__name__` from OTLP attributes to prevent duplicate labels. [#17917](prometheus/prometheus#17917)
- \[BUGFIX] TSDB: Fix division by zero when computing stale series ratio with empty head. [#17952](prometheus/prometheus#17952)
- \[BUGFIX] OTLP: Fix potential silent data loss for sum metrics. [#17954](prometheus/prometheus#17954)
- \[BUGFIX] PromQL: Fix smoothed interpolation across counter resets. [#17988](prometheus/prometheus#17988)
- \[BUGFIX] PromQL: Fix panic with `@` modifier on empty ranges. [#18020](prometheus/prometheus#18020)
- \[BUGFIX] PromQL: Fix `avg_over_time` for a single native histogram. [#18058](prometheus/prometheus#18058)
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