Add 'ignoring' as modifier for binops.

Where 'on' uses the given labels to match,
'ignoring' uses all other labels to match.

group_left/right is not supported yet.

promql/ast.go

@@ -231,6 +231,9 @@ type VectorMatching struct {
 	// On contains the labels which define equality of a pair
 	// of elements from the vectors.
 	On model.LabelNames
+	// Ignoring excludes the given label names from matching,
+	// rather than only using them.
+	Ignoring bool
 	// Include contains additional labels that should be included in
 	// the result from the side with the higher cardinality.
 	Include model.LabelNames

promql/engine.go

@@ -728,7 +728,7 @@ func (ev *evaluator) vectorAnd(lhs, rhs vector, matching *VectorMatching) vector
 	if matching.Card != CardManyToMany {
 		panic("set operations must only use many-to-many matching")
 	}
-	sigf := signatureFunc(matching.On...)
+	sigf := signatureFunc(matching.Ignoring, matching.On...)
 
 	var result vector
 	// The set of signatures for the right-hand side vector.
@@ -751,7 +751,7 @@ func (ev *evaluator) vectorOr(lhs, rhs vector, matching *VectorMatching) vector
 	if matching.Card != CardManyToMany {
 		panic("set operations must only use many-to-many matching")
 	}
-	sigf := signatureFunc(matching.On...)
+	sigf := signatureFunc(matching.Ignoring, matching.On...)
 
 	var result vector
 	leftSigs := map[uint64]struct{}{}
@@ -773,7 +773,7 @@ func (ev *evaluator) vectorUnless(lhs, rhs vector, matching *VectorMatching) vec
 	if matching.Card != CardManyToMany {
 		panic("set operations must only use many-to-many matching")
 	}
-	sigf := signatureFunc(matching.On...)
+	sigf := signatureFunc(matching.Ignoring, matching.On...)
 
 	rightSigs := map[uint64]struct{}{}
 	for _, rs := range rhs {
@@ -796,7 +796,7 @@ func (ev *evaluator) vectorBinop(op itemType, lhs, rhs vector, matching *VectorM
 	}
 	var (
 		result       = vector{}
-		sigf         = signatureFunc(matching.On...)
+		sigf         = signatureFunc(matching.Ignoring, matching.On...)
 		resultLabels = append(matching.On, matching.Include...)
 	)
 
@@ -851,7 +851,7 @@ func (ev *evaluator) vectorBinop(op itemType, lhs, rhs vector, matching *VectorM
 		} else if !keep {
 			continue
 		}
-		metric := resultMetric(ls.Metric, op, resultLabels...)
+		metric := resultMetric(ls.Metric, op, matching.Ignoring, resultLabels...)
 
 		insertedSigs, exists := matchedSigs[sig]
 		if matching.Card == CardOneToOne {
@@ -883,12 +883,16 @@ func (ev *evaluator) vectorBinop(op itemType, lhs, rhs vector, matching *VectorM
 }
 
 // signatureFunc returns a function that calculates the signature for a metric
-// based on the provided labels.
-func signatureFunc(labels ...model.LabelName) func(m metric.Metric) uint64 {
-	if len(labels) == 0 {
+// based on the provided labels. If ignoring, then the given labels are ignored instead.
+func signatureFunc(ignoring bool, labels ...model.LabelName) func(m metric.Metric) uint64 {
+	if len(labels) == 0 || ignoring {
 		return func(m metric.Metric) uint64 {
-			m.Del(model.MetricNameLabel)
-			return uint64(m.Metric.Fingerprint())
+			tmp := m.Metric.Clone()
+			for _, l := range labels {
+				delete(tmp, l)
+			}
+			delete(tmp, model.MetricNameLabel)
+			return uint64(tmp.Fingerprint())
 		}
 	}
 	return func(m metric.Metric) uint64 {
@@ -898,11 +902,14 @@ func signatureFunc(labels ...model.LabelName) func(m metric.Metric) uint64 {
 
 // resultMetric returns the metric for the given sample(s) based on the vector
 // binary operation and the matching options.
-func resultMetric(met metric.Metric, op itemType, labels ...model.LabelName) metric.Metric {
-	if len(labels) == 0 {
+func resultMetric(met metric.Metric, op itemType, ignoring bool, labels ...model.LabelName) metric.Metric {
+	if len(labels) == 0 || ignoring {
 		if shouldDropMetricName(op) {
 			met.Del(model.MetricNameLabel)
 		}
+		for _, l := range labels {
+			met.Del(l)
+		}
 		return met
 	}
 	// As we definitely write, creating a new metric is the easiest solution.

promql/lex.go

@@ -172,6 +172,7 @@ const (
 	itemBy
 	itemWithout
 	itemOn
+	itemIgnoring
 	itemGroupLeft
 	itemGroupRight
 	itemBool
@@ -209,6 +210,7 @@ var key = map[string]itemType{
 	"keeping_extra": itemKeepCommon,
 	"keep_common":   itemKeepCommon,
 	"on":            itemOn,
+	"ignoring":      itemIgnoring,
 	"group_left":    itemGroupLeft,
 	"group_right":   itemGroupRight,
 	"bool":          itemBool,

promql/lex_test.go

@@ -278,6 +278,9 @@ var tests = []struct {
 	}, {
 		input:    "on",
 		expected: []item{{itemOn, 0, "on"}},
+	}, {
+		input:    "ignoring",
+		expected: []item{{itemIgnoring, 0, "ignoring"}},
 	}, {
 		input:    "group_left",
 		expected: []item{{itemGroupLeft, 0, "group_left"}},

promql/parse.go

@@ -462,7 +462,10 @@ func (p *parser) expr() Expr {
 		}
 
 		// Parse ON clause.
-		if p.peek().typ == itemOn {
+		if p.peek().typ == itemOn || p.peek().typ == itemIgnoring {
+			if p.peek().typ == itemIgnoring {
+				vecMatching.Ignoring = true
+			}
 			p.next()
 			vecMatching.On = p.labels()
 
@@ -478,6 +481,10 @@ func (p *parser) expr() Expr {
 			}
 		}
 
+		if vecMatching.Ignoring && (vecMatching.Card == CardManyToOne || vecMatching.Card == CardOneToMany) {
+			p.errorf("IGNORING not permitted with many to one matching")
+		}
+
 		for _, ln := range vecMatching.On {
 			for _, ln2 := range vecMatching.Include {
 				if ln == ln2 {

promql/parse_test.go

@@ -250,6 +250,14 @@ var testExpr = []struct {
 		input:  "1 offset 1d",
 		fail:   true,
 		errMsg: "offset modifier must be preceded by an instant or range selector",
+	}, {
+		input:  "a - on(b) ignoring(c) d",
+		fail:   true,
+		errMsg: "parse error at char 11: no valid expression found",
+	}, {
+		input:  "a - ignoring(b) group_left(c) d",
+		fail:   true,
+		errMsg: "parse error at char 29: IGNORING not permitted with many to one matching",
 	},
 	// Vector binary operations.
 	{
@@ -517,6 +525,28 @@ var testExpr = []struct {
 				On:   model.LabelNames{"test", "blub"},
 			},
 		},
+	}, {
+		input: "foo and ignoring(test,blub) bar",
+		expected: &BinaryExpr{
+			Op: itemLAND,
+			LHS: &VectorSelector{
+				Name: "foo",
+				LabelMatchers: metric.LabelMatchers{
+					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "foo"},
+				},
+			},
+			RHS: &VectorSelector{
+				Name: "bar",
+				LabelMatchers: metric.LabelMatchers{
+					{Type: metric.Equal, Name: model.MetricNameLabel, Value: "bar"},
+				},
+			},
+			VectorMatching: &VectorMatching{
+				Card:     CardManyToMany,
+				On:       model.LabelNames{"test", "blub"},
+				Ignoring: true,
+			},
+		},
 	}, {
 		input: "foo unless on(bar) baz",
 		expected: &BinaryExpr{

promql/printer.go

@@ -160,7 +160,11 @@ func (node *BinaryExpr) String() string {
 	matching := ""
 	vm := node.VectorMatching
 	if vm != nil && len(vm.On) > 0 {
-		matching = fmt.Sprintf(" ON(%s)", vm.On)
+		if vm.Ignoring {
+			matching = fmt.Sprintf(" IGNORING(%s)", vm.On)
+		} else {
+			matching = fmt.Sprintf(" ON(%s)", vm.On)
+		}
 		if vm.Card == CardManyToOne {
 			matching += fmt.Sprintf(" GROUP_LEFT(%s)", vm.Include)
 		}

promql/printer_test.go

@@ -36,6 +36,12 @@ func TestExprString(t *testing.T) {
 		{
 			in: `sum(task:errors:rate10s{job="s"}) WITHOUT (instance)`,
 		},
+		{
+			in: `a - ON(b) c`,
+		},
+		{
+			in: `a - IGNORING(b) c`,
+		},
 		{
 			in: `up > BOOL 0`,
 		},

promql/testdata/operators.test

@@ -79,6 +79,14 @@ eval instant at 50m (http_requests{group="canary"} + 1) and on(instance) http_re
 	{group="canary", instance="0", job="api-server"} 301
 	{group="canary", instance="0", job="app-server"} 701
 
+eval instant at 50m (http_requests{group="canary"} + 1) and ignoring(group) http_requests{instance="0", group="production"}
+	{group="canary", instance="0", job="api-server"} 301
+	{group="canary", instance="0", job="app-server"} 701
+
+eval instant at 50m (http_requests{group="canary"} + 1) and ignoring(group, job) http_requests{instance="0", group="production"}
+	{group="canary", instance="0", job="api-server"} 301
+	{group="canary", instance="0", job="app-server"} 701
+
 eval instant at 50m http_requests{group="canary"} or http_requests{group="production"}
 	http_requests{group="canary", instance="0", job="api-server"} 300
 	http_requests{group="canary", instance="0", job="app-server"} 700
@@ -109,6 +117,14 @@ eval instant at 50m (http_requests{group="canary"} + 1) or on(instance) (http_re
 	vector_matching_a{l="x"} 10
 	vector_matching_a{l="y"} 20
 
+eval instant at 50m (http_requests{group="canary"} + 1) or ignoring(l, group, job) (http_requests or cpu_count or vector_matching_a)
+	{group="canary", instance="0", job="api-server"} 301
+	{group="canary", instance="0", job="app-server"} 701
+	{group="canary", instance="1", job="api-server"} 401
+	{group="canary", instance="1", job="app-server"} 801
+	vector_matching_a{l="x"} 10
+	vector_matching_a{l="y"} 20
+
 eval instant at 50m http_requests{group="canary"} unless http_requests{instance="0"}
 	http_requests{group="canary", instance="1", job="api-server"} 400
 	http_requests{group="canary", instance="1", job="app-server"} 800
@@ -125,6 +141,18 @@ eval instant at 50m http_requests{group="canary"} / on(instance,job) http_reques
 	{instance="1", job="api-server"} 2
 	{instance="1", job="app-server"} 1.3333333333333333
 
+eval instant at 50m http_requests{group="canary"} unless ignoring(group, instance) http_requests{instance="0"}
+
+eval instant at 50m http_requests{group="canary"} unless ignoring(group) http_requests{instance="0"}
+	http_requests{group="canary", instance="1", job="api-server"} 400
+	http_requests{group="canary", instance="1", job="app-server"} 800
+
+eval instant at 50m http_requests{group="canary"} / ignoring(group) http_requests{group="production"}
+	{instance="0", job="api-server"} 3
+	{instance="0", job="app-server"} 1.4
+	{instance="1", job="api-server"} 2
+	{instance="1", job="app-server"} 1.3333333333333333
+
 # https://github.com/prometheus/prometheus/issues/1489
 eval instant at 50m http_requests AND ON (dummy) vector(1)
 	http_requests{group="canary", instance="0", job="api-server"} 300
@@ -136,6 +164,16 @@ eval instant at 50m http_requests AND ON (dummy) vector(1)
 	http_requests{group="production", instance="1", job="api-server"} 200
 	http_requests{group="production", instance="1", job="app-server"} 600
 
+eval instant at 50m http_requests AND IGNORING (group, instance, job) vector(1)
+	http_requests{group="canary", instance="0", job="api-server"} 300
+	http_requests{group="canary", instance="0", job="app-server"} 700
+	http_requests{group="canary", instance="1", job="api-server"} 400
+	http_requests{group="canary", instance="1", job="app-server"} 800
+	http_requests{group="production", instance="0", job="api-server"} 100
+	http_requests{group="production", instance="0", job="app-server"} 500
+	http_requests{group="production", instance="1", job="api-server"} 200
+	http_requests{group="production", instance="1", job="app-server"} 600
+
 
 # Comparisons.
 eval instant at 50m SUM(http_requests) BY (job) > 1000