fix(indexstats): do not collect stats for idxstats queries while exec…

…uting other query types

pkg/querier/queryrange/roundtrip.go

@@ -274,7 +274,7 @@ func NewMiddleware(
 			seriesRT         = seriesTripperware.Wrap(next)
 			labelsRT         = labelsTripperware.Wrap(next)
 			instantRT        = instantMetricTripperware.Wrap(next)
-			statsRT          = indexStatsTripperware.Wrap(next)
+			statsRT          = base.MergeMiddlewares(StatsCollectorMiddleware(), indexStatsTripperware).Wrap(next)
 			seriesVolumeRT   = seriesVolumeTripperware.Wrap(next)
 			detectedFieldsRT = detectedFieldsTripperware.Wrap(next)
 			detectedLabelsRT = detectedLabelsTripperware.Wrap(next)
@@ -1018,22 +1018,6 @@ func NewVolumeTripperware(cfg Config, log log.Logger, limits Limits, schema conf
 	), nil
 }
 
-func statsTripperware(nextTW base.Middleware) base.Middleware {
-	return base.MiddlewareFunc(func(next base.Handler) base.Handler {
-		return base.HandlerFunc(func(ctx context.Context, r base.Request) (base.Response, error) {
-			cacheMiddlewares := []base.Middleware{
-				StatsCollectorMiddleware(),
-				nextTW,
-			}
-
-			// wrap nextRT with our new middleware
-			return base.MergeMiddlewares(
-				cacheMiddlewares...,
-			).Wrap(next).Do(ctx, r)
-		})
-	})
-}
-
 func volumeRangeTripperware(nextTW base.Middleware) base.Middleware {
 	return base.MiddlewareFunc(func(next base.Handler) base.Handler {
 		return base.HandlerFunc(func(ctx context.Context, r base.Request) (base.Response, error) {
@@ -1104,7 +1088,7 @@ func NewIndexStatsTripperware(cfg Config, log log.Logger, limits Limits, schema
 		}
 	}
 
-	tw, err := sharedIndexTripperware(
+	return sharedIndexTripperware(
 		cacheMiddleware,
 		cfg,
 		merger,
@@ -1115,11 +1099,6 @@ func NewIndexStatsTripperware(cfg Config, log log.Logger, limits Limits, schema
 		schema,
 		metricsNamespace,
 	)
-	if err != nil {
-		return nil, err
-	}
-
-	return statsTripperware(tw), nil
 }
 
 func sharedIndexTripperware(