enable query stats logging and metrics

cmd/thanos/query_frontend.go

@@ -147,6 +147,8 @@ func registerQueryFrontend(app *extkingpin.App) {
 	cmd.Flag("query-frontend.log-queries-longer-than", "Log queries that are slower than the specified duration. "+
 		"Set to 0 to disable. Set to < 0 to enable on all queries.").Default("0").DurationVar(&cfg.CortexHandlerConfig.LogQueriesLongerThan)
 
+	cmd.Flag("query-frontend.query-stats-enabled", "Enable query stats logging and metrics").Default("true").BoolVar(&cfg.CortexHandlerConfig.QueryStatsEnabled)
+
 	cmd.Flag("query-frontend.log-failed-queries", "Log failed queries due to any reason").Default("true").BoolVar(&cfg.CortexHandlerConfig.LogFailedQueries)
 
 	cmd.Flag("failed-query-cache-capacity", "Capacity of cache for failed queries. 0 means this feature is disabled.").