Add descriptionw when using Thanos Promql engine

Signed-off-by: SungJin1212 <tjdwls1201@gmail.com>

Author: SungJin1212

docs/configuration/config-file-reference.md

@@ -3994,7 +3994,9 @@ The `limits_config` configures default and per-tenant limits imposed by Cortex s
 [promote_resource_attributes: <list of string> | default = ]
 
 # EXPERIMENTAL: If true, the __type__ and __unit__ labels are added to metrics.
-# This applies to remote write v2 and OTLP requests.
+# This applies to remote write v2 and OTLP requests. When using the Thanos
+# PromQL engine, the `__type__` and `__unit__` labels are currently not dropped
+# along with the `__name__` label.
 # CLI flag: -distributor.enable-type-and-unit-labels
 [enable_type_and_unit_labels: <boolean> | default = false]
 

pkg/util/validation/limits.go

@@ -265,7 +265,7 @@ func (l *Limits) RegisterFlags(f *flag.FlagSet) {
 	f.IntVar(&l.HAMaxClusters, "distributor.ha-tracker.max-clusters", 0, "Maximum number of clusters that HA tracker will keep track of for single user. 0 to disable the limit.")
 	f.Var((*flagext.StringSliceCSV)(&l.PromoteResourceAttributes), "distributor.promote-resource-attributes", "Comma separated list of resource attributes that should be converted to labels.")
 	f.Var(&l.DropLabels, "distributor.drop-label", "This flag can be used to specify label names that to drop during sample ingestion within the distributor and can be repeated in order to drop multiple labels.")
-	f.BoolVar(&l.EnableTypeAndUnitLabels, "distributor.enable-type-and-unit-labels", false, "EXPERIMENTAL: If true, the __type__ and __unit__ labels are added to metrics. This applies to remote write v2 and OTLP requests.")
+	f.BoolVar(&l.EnableTypeAndUnitLabels, "distributor.enable-type-and-unit-labels", false, "EXPERIMENTAL: If true, the __type__ and __unit__ labels are added to metrics. This applies to remote write v2 and OTLP requests. When using the Thanos PromQL engine, the `__type__` and `__unit__` labels are currently not dropped along with the `__name__` label.")
 	f.IntVar(&l.MaxLabelNameLength, "validation.max-length-label-name", 1024, "Maximum length accepted for label names")
 	f.IntVar(&l.MaxLabelValueLength, "validation.max-length-label-value", 2048, "Maximum length accepted for label value. This setting also applies to the metric name")
 	f.IntVar(&l.MaxLabelNamesPerSeries, "validation.max-label-names-per-series", 30, "Maximum number of label names per series.")

schemas/cortex-config-schema.json

@@ -4942,7 +4942,7 @@
         },
         "enable_type_and_unit_labels": {
           "default": false,
-          "description": "EXPERIMENTAL: If true, the __type__ and __unit__ labels are added to metrics. This applies to remote write v2 and OTLP requests.",
+          "description": "EXPERIMENTAL: If true, the __type__ and __unit__ labels are added to metrics. This applies to remote write v2 and OTLP requests. When using the Thanos PromQL engine, the `__type__` and `__unit__` labels are currently not dropped along with the `__name__` label.",
           "type": "boolean",
           "x-cli-flag": "distributor.enable-type-and-unit-labels"
         },