fix(sharding): use without() grouping when merging avg_over_time sh…

…ard results (#12176)

pkg/logql/downstream_test.go

@@ -57,6 +57,9 @@ func TestMappingEquivalence(t *testing.T) {
 		{`sum(rate({a=~".+"} |= "foo" != "foo"[1s]) or vector(1))`, false, nil},
 		{`avg_over_time({a=~".+"} | logfmt | unwrap value [1s])`, false, nil},
 		{`avg_over_time({a=~".+"} | logfmt | unwrap value [1s]) by (a)`, true, nil},
+		{`avg_over_time({a=~".+"} | logfmt | unwrap value [1s]) without (stream)`, true, nil},
+		{`avg_over_time({a=~".+"} | logfmt | drop level | unwrap value [1s])`, true, nil},
+		{`avg_over_time({a=~".+"} | logfmt | drop level | unwrap value [1s]) without (stream)`, true, nil},
 		{`quantile_over_time(0.99, {a=~".+"} | logfmt | unwrap value [1s])`, true, []string{ShardQuantileOverTime}},
 		{
 			`

pkg/logql/shardmapper.go

@@ -397,13 +397,18 @@ func (m ShardMapper) mapRangeAggregationExpr(expr *syntax.RangeAggregationExpr,
 			return m.mapSampleExpr(expr, r)
 		}
 
+		grouping := expr.Grouping
+		if grouping == nil {
+			grouping = &syntax.Grouping{Without: true}
+		}
+
 		// avg_over_time() by (foo) -> sum by (foo) (sum_over_time()) / sum by (foo) (count_over_time())
 		lhs, lhsBytesPerShard, err := m.mapVectorAggregationExpr(&syntax.VectorAggregationExpr{
 			Left: &syntax.RangeAggregationExpr{
 				Left:      expr.Left,
 				Operation: syntax.OpRangeTypeSum,
 			},
-			Grouping:  expr.Grouping,
+			Grouping:  grouping,
 			Operation: syntax.OpTypeSum,
 		}, r, false)
 		if err != nil {
@@ -416,12 +421,21 @@ func (m ShardMapper) mapRangeAggregationExpr(expr *syntax.RangeAggregationExpr,
 			return nil, 0, err
 		}
 
+		// labelSampleExtractor includes the unwrap identifier in without() list if no grouping is specified
+		// similar change is required for the RHS here to ensure the resulting label sets match
+		rhsGrouping := *grouping
+		if rhsGrouping.Without {
+			if expr.Left.Unwrap != nil {
+				rhsGrouping.Groups = append(rhsGrouping.Groups, expr.Left.Unwrap.Identifier)
+			}
+		}
+
 		rhs, rhsBytesPerShard, err := m.mapVectorAggregationExpr(&syntax.VectorAggregationExpr{
 			Left: &syntax.RangeAggregationExpr{
 				Left:      countOverTimeSelector,
 				Operation: syntax.OpRangeTypeCount,
 			},
-			Grouping:  expr.Grouping,
+			Grouping:  &rhsGrouping,
 			Operation: syntax.OpTypeSum,
 		}, r, false)
 		if err != nil {

pkg/logql/shardmapper_test.go

@@ -392,6 +392,38 @@ func TestMappingStrings(t *testing.T) {
 				)
 			)`,
 		},
+		{
+			in: `avg_over_time({job=~"myapps.*"} |= "stats" | json | keep busy | unwrap busy [5m])`,
+			out: `(
+				sum without() (
+					downstream<sum without() (sum_over_time({job=~"myapps.*"} |="stats" | json | keep busy | unwrap busy [5m])),shard=0_of_2>
+					++
+					downstream<sum without() (sum_over_time({job=~"myapps.*"} |="stats" | json | keep busy | unwrap busy [5m])),shard=1_of_2>
+				)
+				/
+				sum without(busy) (
+					downstream<sum without(busy) (count_over_time({job=~"myapps.*"} |="stats" | json | keep busy [5m])),shard=0_of_2>
+					++
+					downstream<sum without(busy) (count_over_time({job=~"myapps.*"} |="stats" | json | keep busy [5m])),shard=1_of_2>
+				)
+			)`,
+		},
+		{
+			in: `avg_over_time({job=~"myapps.*"} |= "stats" | json | keep busy | unwrap busy [5m]) without (foo)`,
+			out: `(
+				sum without(foo) (
+					downstream<sum without(foo) (sum_over_time({job=~"myapps.*"} |="stats" | json | keep busy | unwrap busy [5m])),shard=0_of_2>
+					++
+					downstream<sum without(foo) (sum_over_time({job=~"myapps.*"} |="stats" | json | keep busy | unwrap busy [5m])),shard=1_of_2>
+				)
+				/
+				sum without(foo,busy) (
+					downstream<sum without(foo,busy) (count_over_time({job=~"myapps.*"} |="stats" | json | keep busy [5m])),shard=0_of_2>
+					++
+					downstream<sum without(foo,busy) (count_over_time({job=~"myapps.*"} |="stats" | json | keep busy [5m])),shard=1_of_2>
+				)
+			)`,
+		},
 		// should be noop if VectorExpr
 		{
 			in:  `vector(0)`,