Opmizing GetLabels and GetLabels values from store gateway

Signed-off-by: Alan Protasio <[email protected]>

Author: alanprot

pkg/querier/blocks_store_queryable.go

@@ -345,7 +345,7 @@ func (q *blocksStoreQuerier) LabelNames(ctx context.Context, matchers ...*labels
 
 	var (
 		resMtx            sync.Mutex
-		resNameSets       = [][]string{}
+		resNameSet        = []string{}
 		resWarnings       = annotations.Annotations(nil)
 		convertedMatchers = convertMatchersToLabelMatcher(matchers)
 	)
@@ -357,7 +357,7 @@ func (q *blocksStoreQuerier) LabelNames(ctx context.Context, matchers ...*labels
 		}
 
 		resMtx.Lock()
-		resNameSets = append(resNameSets, nameSets...)
+		resNameSet = strutil.MergeSlices(resNameSet, nameSets)
 		resWarnings.Merge(warnings)
 		resMtx.Unlock()
 
@@ -368,7 +368,7 @@ func (q *blocksStoreQuerier) LabelNames(ctx context.Context, matchers ...*labels
 		return nil, nil, err
 	}
 
-	return strutil.MergeSlices(resNameSets...), resWarnings, nil
+	return resNameSet, resWarnings, nil
 }
 
 func (q *blocksStoreQuerier) LabelValues(ctx context.Context, name string, matchers ...*labels.Matcher) ([]string, annotations.Annotations, error) {
@@ -383,7 +383,7 @@ func (q *blocksStoreQuerier) LabelValues(ctx context.Context, name string, match
 	minT, maxT := q.minT, q.maxT
 
 	var (
-		resValueSets = [][]string{}
+		resValueSets = []string{}
 		resWarnings  = annotations.Annotations(nil)
 
 		resultMtx sync.Mutex
@@ -396,7 +396,7 @@ func (q *blocksStoreQuerier) LabelValues(ctx context.Context, name string, match
 		}
 
 		resultMtx.Lock()
-		resValueSets = append(resValueSets, valueSets...)
+		resValueSets = strutil.MergeSlices(resValueSets, valueSets)
 		resWarnings.Merge(warnings)
 		resultMtx.Unlock()
 
@@ -407,7 +407,7 @@ func (q *blocksStoreQuerier) LabelValues(ctx context.Context, name string, match
 		return nil, nil, err
 	}
 
-	return strutil.MergeSlices(resValueSets...), resWarnings, nil
+	return resValueSets, resWarnings, nil
 }
 
 func (q *blocksStoreQuerier) Close() error {
@@ -819,12 +819,12 @@ func (q *blocksStoreQuerier) fetchLabelNamesFromStore(
 	minT int64,
 	maxT int64,
 	matchers []storepb.LabelMatcher,
-) ([][]string, annotations.Annotations, []ulid.ULID, error, error) {
+) ([]string, annotations.Annotations, []ulid.ULID, error, error) {
 	var (
 		reqCtx        = grpc_metadata.AppendToOutgoingContext(ctx, cortex_tsdb.TenantIDExternalLabel, userID)
 		g, gCtx       = errgroup.WithContext(reqCtx)
 		mtx           = sync.Mutex{}
-		nameSets      = [][]string{}
+		nameSet       = []string{}
 		warnings      = annotations.Annotations(nil)
 		queriedBlocks = []ulid.ULID(nil)
 		spanLog       = spanlogger.FromContext(ctx)
@@ -894,7 +894,7 @@ func (q *blocksStoreQuerier) fetchLabelNamesFromStore(
 
 			// Store the result.
 			mtx.Lock()
-			nameSets = append(nameSets, namesResp.Names)
+			nameSet = strutil.MergeSlices(nameSet, namesResp.Names)
 			for _, w := range namesResp.Warnings {
 				warnings.Add(errors.New(w))
 			}
@@ -910,7 +910,7 @@ func (q *blocksStoreQuerier) fetchLabelNamesFromStore(
 		return nil, nil, nil, err, merr.Err()
 	}
 
-	return nameSets, warnings, queriedBlocks, nil, merr.Err()
+	return nameSet, warnings, queriedBlocks, nil, merr.Err()
 }
 
 func (q *blocksStoreQuerier) fetchLabelValuesFromStore(
@@ -921,12 +921,12 @@ func (q *blocksStoreQuerier) fetchLabelValuesFromStore(
 	minT int64,
 	maxT int64,
 	matchers ...*labels.Matcher,
-) ([][]string, annotations.Annotations, []ulid.ULID, error, error) {
+) ([]string, annotations.Annotations, []ulid.ULID, error, error) {
 	var (
 		reqCtx        = grpc_metadata.AppendToOutgoingContext(ctx, cortex_tsdb.TenantIDExternalLabel, userID)
 		g, gCtx       = errgroup.WithContext(reqCtx)
 		mtx           = sync.Mutex{}
-		valueSets     = [][]string{}
+		valueSet      = []string{}
 		warnings      = annotations.Annotations(nil)
 		queriedBlocks = []ulid.ULID(nil)
 		spanLog       = spanlogger.FromContext(ctx)
@@ -995,11 +995,13 @@ func (q *blocksStoreQuerier) fetchLabelValuesFromStore(
 				"queried blocks", strings.Join(convertULIDsToString(myQueriedBlocks), " "))
 
 			// Values returned need not be sorted, but we need them to be sorted so we can merge.
-			sort.Strings(valuesResp.Values)
+			if !sort.StringsAreSorted(valuesResp.Values) {
+				sort.Strings(valuesResp.Values)
+			}
 
 			// Store the result.
 			mtx.Lock()
-			valueSets = append(valueSets, valuesResp.Values)
+			valueSet = strutil.MergeSlices(valueSet, valuesResp.Values)
 			for _, w := range valuesResp.Warnings {
 				warnings.Add(errors.New(w))
 			}
@@ -1015,7 +1017,7 @@ func (q *blocksStoreQuerier) fetchLabelValuesFromStore(
 		return nil, nil, nil, err, merr.Err()
 	}
 
-	return valueSets, warnings, queriedBlocks, nil, merr.Err()
+	return valueSet, warnings, queriedBlocks, nil, merr.Err()
 }
 
 func createSeriesRequest(minT, maxT int64, matchers []storepb.LabelMatcher, shardingInfo *storepb.ShardInfo, skipChunks bool, blockIDs []ulid.ULID) (*storepb.SeriesRequest, error) {