app/vmselect: add retention and downsampling filters debug pages (#776)

https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6304

---------

Signed-off-by: Zakhar Bessarab <z.bessarab@victoriametrics.com>
Co-authored-by: hagen1778 <roman@victoriametrics.com>
Signed-off-by: hagen1778 <roman@victoriametrics.com>

docs/README.md

@@ -351,6 +351,8 @@ The UI allows exploring query results via graphs and tables. It also provides th
   - [Query analyzer](#query-tracing) - playground for loading query results and traces in JSON format. See `Export query` button below;  
   - [WITH expressions playground](https://play.victoriametrics.com/select/accounting/1/6a716b0f-38bc-4856-90ce-448fd713e3fe/prometheus/graph/#/expand-with-exprs) - test how WITH expressions work; 
   - [Metric relabel debugger](https://play.victoriametrics.com/select/accounting/1/6a716b0f-38bc-4856-90ce-448fd713e3fe/prometheus/graph/#/relabeling) - playground for [relabeling](#relabeling) configs.
+  - [Downsampling filters debugger](https://play.victoriametrics.com/select/accounting/1/6a716b0f-38bc-4856-90ce-448fd713e3fe/prometheus/graph/#/downsampling-filters-debug) - playground for [relabeling](#downsampling) configs.
+  - [Retention filters debugger](https://play.victoriametrics.com/select/accounting/1/6a716b0f-38bc-4856-90ce-448fd713e3fe/prometheus/graph/#/retention-filters-debug) - playground for [relabeling](#retention-filters) configs.
 
 VMUI provides auto-completion for [MetricsQL](https://docs.victoriametrics.com/metricsql/) functions, metric names, label names and label values. The auto-completion can be enabled
 by checking the `Autocomplete` toggle. When the auto-completion is disabled, it can still be triggered for the current cursor position by pressing `ctrl+space`.
@@ -2040,6 +2042,7 @@ Important notes:
   So the IndexDB size can grow big under [high churn rate](https://docs.victoriametrics.com/faq/#what-is-high-churn-rate)
   even for small retentions configured via `-retentionFilter`.
 
+Retention filters configuration can be tested in enterprise version of vmui on the page `Tools.Retnetion filters debug`.
 It is safe updating `-retentionFilter` during VictoriaMetrics restarts - the updated retention filters are applied eventually
 to historical data.
 
@@ -2066,7 +2069,8 @@ via `-downsampling.period=filter:offset:interval` syntax. In this case the given
 The `filter` can contain arbitrary [series filter](https://docs.victoriametrics.com/keyconcepts/#filtering).
 For example, `-downsampling.period='{__name__=~"(node|process)_.*"}:1d:1m` instructs VictoriaMetrics to deduplicate samples older than one day with one minute interval
 only for [time series](https://docs.victoriametrics.com/keyconcepts/#time-series) with names starting with `node_` or `process_` prefixes.
-The de-duplication for other time series can be configured independently via additional `-downsampling.period` command-line flags.
+The deduplication for other time series can be configured independently via additional `-downsampling.period` command-line flags.
+Downsampling configuration can be tested in enterprise version of vmui on the page `Tools.Downsampling filters debug`.
 
 If the time series doesn't match any `filter`, then it isn't downsampled. If the time series matches multiple filters, then the downsampling
 for the first matching `filter` is applied. For example, `-downsampling.period='{env="prod"}:1d:30s,{__name__=~"node_.*"}:1d:5m'` de-duplicates

docs/changelog/CHANGELOG.md

@@ -33,6 +33,7 @@ Released at 2024-10-21
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert/): `-rule` cmd-line flag now supports multi-document YAML files. This could be useful when rules are retrieved via HTTP URL where multiple rule files were merged together in one response. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6753). Thanks to @Irene-123 for [the pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6995).
 * FEATURE: [vmgateway](https://docs.victoriametrics.com/vmgateway/): allow parsing `scope` claim parsing in array format. This is useful for cases when identity provider does encode claims in array format.
 * FEATURE: [vmui](https://docs.victoriametrics.com/#vmui): add the ability to cancel running queries. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7097).
+* FEATURE: [vmui](https://docs.victoriametrics.com/#vmui): add playgrounds for [retention filters](https://docs.victoriametrics.com/single-server-victoriametrics/#retention-filters) and [downsampling](https://docs.victoriametrics.com/single-server-victoriametrics/#downsampling) configurations. These new pages are available in vmui in the `Tools` section. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6304).
 
 * BUGFIX: [vmgateway](https://docs.victoriametrics.com/vmgateway/): fix possible panic during parsing of a token without `vm_access` claim. This issue was introduced in v1.104.0.
 * BUGFIX: [vmui](https://docs.victoriametrics.com/#vmui): fix error messages rendering from overflowing the screen with long messages. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/7207).