Revert "Modify astmapper to handle the query format for cross-cluster…

… federation"

This reverts commit fc2ffad.

pkg/frontend/querymiddleware/astmapper/sharding.go

@@ -19,7 +19,7 @@ import (
 
 // NewSharding creates a new query sharding mapper.
 func NewSharding(ctx context.Context, shards int, logger log.Logger, stats *MapperStats) (ASTMapper, error) {
-	shardSummer, err := newShardSummer(ctx, shards, vectorSquasher, logger, stats, nil)
+	shardSummer, err := newShardSummer(ctx, shards, vectorSquasher, logger, stats)
 	if err != nil {
 		return nil, err
 	}
@@ -41,28 +41,15 @@ type shardSummer struct {
 	logger       log.Logger
 	stats        *MapperStats
 
-	splitLabel string
-	clusters   []string
-
 	canShardAllVectorSelectorsCache map[string]bool
 }
 
-// newShardSummer instantiates an ASTMapper which will fan out sum queries by shard. If clusters is defined,
-// the mapper will be used to rewrite the queries for cross-cluster query federation. Otherwise, it will
-// rewrite the queries for query sharding.
-func newShardSummer(ctx context.Context, shards int, squasher squasher, logger log.Logger, stats *MapperStats, clusters []string) (ASTMapper, error) {
+// newShardSummer instantiates an ASTMapper which will fan out sum queries by shard
+func newShardSummer(ctx context.Context, shards int, squasher squasher, logger log.Logger, stats *MapperStats) (ASTMapper, error) {
 	if squasher == nil {
 		return nil, errors.Errorf("squasher required and not passed")
 	}
 
-	var splitLabel string
-	if len(clusters) > 0 {
-		shards = len(clusters)
-		splitLabel = sharding.ClusterLabel
-	} else {
-		splitLabel = sharding.ShardLabel
-	}
-
 	return NewASTExprMapper(&shardSummer{
 		ctx: ctx,
 
@@ -72,9 +59,6 @@ func newShardSummer(ctx context.Context, shards int, squasher squasher, logger l
 		logger:       logger,
 		stats:        stats,
 
-		splitLabel: splitLabel,
-		clusters:   clusters,
-
 		canShardAllVectorSelectorsCache: make(map[string]bool),
 	}), nil
 }
@@ -114,7 +98,7 @@ func (summer *shardSummer) MapExpr(expr parser.Expr) (mapped parser.Expr, finish
 
 	case *parser.VectorSelector:
 		if summer.currentShard != nil {
-			mapped, err := summer.shardVectorSelector(e)
+			mapped, err := shardVectorSelector(*summer.currentShard, summer.shards, e)
 			return mapped, true, err
 		}
 		return e, true, nil
@@ -538,14 +522,8 @@ func (summer *shardSummer) shardAndSquashBinOp(expr *parser.BinaryExpr) (parser.
 	return summer.squash(children...)
 }
 
-func (summer *shardSummer) shardVectorSelector(selector *parser.VectorSelector) (parser.Expr, error) {
-	var splitLabelValue string
-	if len(summer.clusters) > 0 {
-		splitLabelValue = summer.clusters[*summer.currentShard]
-	} else {
-		splitLabelValue = sharding.ShardSelector{ShardIndex: uint64(*summer.currentShard), ShardCount: uint64(summer.shards)}.LabelValue()
-	}
-	shardMatcher, err := labels.NewMatcher(labels.MatchEqual, summer.splitLabel, splitLabelValue)
+func shardVectorSelector(curshard, shards int, selector *parser.VectorSelector) (parser.Expr, error) {
+	shardMatcher, err := labels.NewMatcher(labels.MatchEqual, sharding.ShardLabel, sharding.ShardSelector{ShardIndex: uint64(curshard), ShardCount: uint64(shards)}.LabelValue())
 	if err != nil {
 		return nil, err
 	}

pkg/frontend/querymiddleware/astmapper/sharding_test.go

@@ -577,7 +577,7 @@ func TestShardSummerWithEncoding(t *testing.T) {
 	} {
 		t.Run(fmt.Sprintf("[%d]", i), func(t *testing.T) {
 			stats := NewMapperStats()
-			summer, err := newShardSummer(context.Background(), c.shards, vectorSquasher, log.NewNopLogger(), stats, nil)
+			summer, err := newShardSummer(context.Background(), c.shards, vectorSquasher, log.NewNopLogger(), stats)
 			require.Nil(t, err)
 			expr, err := parser.ParseExpr(c.input)
 			require.Nil(t, err)
@@ -593,41 +593,6 @@ func TestShardSummerWithEncoding(t *testing.T) {
 	}
 }
 
-func TestShardSummerWithClusters(t *testing.T) {
-	clusters := []string{
-		"cluster-a",
-		"cluster-b",
-		"cluster-c",
-		"cluster-d",
-	}
-	clustersSize := len(clusters)
-	for i, c := range []struct {
-		input    string
-		expected string
-	}{
-		{
-			input:    `sum(rate(bar1{baz="blip"}[1m]))`,
-			expected: `sum(__embedded_queries__{__queries__="{\"Concat\":[\"sum(rate(bar1{__cluster__=\\\"cluster-a\\\",baz=\\\"blip\\\"}[1m]))\",\"sum(rate(bar1{__cluster__=\\\"cluster-b\\\",baz=\\\"blip\\\"}[1m]))\",\"sum(rate(bar1{__cluster__=\\\"cluster-c\\\",baz=\\\"blip\\\"}[1m]))\",\"sum(rate(bar1{__cluster__=\\\"cluster-d\\\",baz=\\\"blip\\\"}[1m]))\"]}"})`,
-		},
-	} {
-		t.Run(fmt.Sprintf("[%d]", i), func(t *testing.T) {
-			stats := NewMapperStats()
-			summer, err := newShardSummer(context.Background(), 0, vectorSquasher, log.NewNopLogger(), stats, clusters)
-			require.Nil(t, err)
-			expr, err := parser.ParseExpr(c.input)
-			require.Nil(t, err)
-
-			res, err := summer.Map(expr)
-			require.Nil(t, err)
-			assert.Equal(t, clustersSize, stats.GetShardedQueries())
-			expected, err := parser.ParseExpr(c.expected)
-			require.Nil(t, err)
-
-			require.Equal(t, expected.String(), res.String())
-		})
-	}
-}
-
 func TestIsSubqueryCall(t *testing.T) {
 	tests := []struct {
 		query    string

pkg/storage/sharding/label.go

@@ -12,11 +12,8 @@ import (
 )
 
 const (
-	// ShardLabel is a reserved label referencing a shard on read path used for query sharding.
+	// ShardLabel is a reserved label referencing a shard on read path.
 	ShardLabel = "__query_shard__"
-
-	// ClusterLabel is a reserved label referencing a cluster for cross-cluster query federation.
-	ClusterLabel = "__cluster__"
 )
 
 // ShardSelector holds information about the configured query shard.