remove -querier.at-modifier-enabled flag

Signed-off-by: Ben Ye <benye@amazon.com>

Author: yeya24

CHANGELOG.md

@@ -10,6 +10,7 @@
 * [CHANGE] QueryFrontend/QueryScheduler: Deprecate `-querier.max-outstanding-requests-per-tenant` and `-query-scheduler.max-outstanding-requests-per-tenant` flags. Use frontend.max-outstanding-requests-per-tenant instead. #6146
 * [CHANGE] Ingesters: Enable 'snappy-block' compression on ingester clients by default. #6148
 * [CHANGE] Ruler: Scheduling `ruler.evaluation-delay-duration` to be deprecated. Use the highest value between `ruler.evaluation-delay-duration` and `ruler.query-offset` #6149
+* [CHANGE] Querier: Remove `-querier.at-modifier-enabled` flag. #6157
 * [FEATURE] Ingester/Distributor: Experimental: Enable native histogram ingestion via `-blocks-storage.tsdb.enable-native-histograms` flag. #5986 #6010 #6020
 * [FEATURE] Querier: Enable querying native histogram chunks. #5944 #6031
 * [FEATURE] Query Frontend: Support native histogram in query frontend response. #5996 #6043

pkg/querier/querier.go

@@ -47,7 +47,6 @@ type Config struct {
 	IngesterMetadataStreaming bool          `yaml:"ingester_metadata_streaming"`
 	MaxSamples                int           `yaml:"max_samples"`
 	QueryIngestersWithin      time.Duration `yaml:"query_ingesters_within"`
-	AtModifierEnabled         bool          `yaml:"at_modifier_enabled" doc:"hidden"`
 	EnablePerStepStats        bool          `yaml:"per_step_stats_enabled"`
 
 	// QueryStoreAfter the time after which queries should also be sent to the store and not just ingesters.
@@ -94,8 +93,6 @@ var (
 
 // RegisterFlags adds the flags required to config this to the given FlagSet.
 func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
-	//lint:ignore faillint Need to pass the global logger like this for warning on deprecated methods
-	flagext.DeprecatedFlag(f, "querier.at-modifier-enabled", "This flag is no longer functional; at-modifier is always enabled now.", util_log.Logger)
 	//lint:ignore faillint Need to pass the global logger like this for warning on deprecated methods
 	flagext.DeprecatedFlag(f, "querier.ingester-streaming", "Deprecated: Use streaming RPCs to query ingester. QueryStream is always enabled and the flag is not effective anymore.", util_log.Logger)
 	//lint:ignore faillint Need to pass the global logger like this for warning on deprecated methods