show list of offending labels in the error message in many-to-many scenarios (#5189)

Signed-off-by: tariqibrahim <tariq181290@gmail.com>
This commit is contained in:
Tariq Ibrahim 2019-02-09 01:17:52 -08:00 committed by Julius Volz
parent b26b5c9e96
commit a2a6e24f9f
3 changed files with 132 additions and 2 deletions

View file

@ -81,6 +81,25 @@ func (ls *Labels) UnmarshalJSON(b []byte) error {
return nil
}
// MatchLabels returns a subset of Labels that matches/does not match with the provided label names based on the 'on' boolean.
// If on is set to true, it returns the subset of labels that match with the provided label names and its inverse when 'on' is set to false.
func (ls Labels) MatchLabels(on bool, names ...string) Labels {
matchedLabels := Labels{}
nameSet := map[string]struct{}{}
for _, n := range names {
nameSet[n] = struct{}{}
}
for _, v := range ls {
if _, ok := nameSet[v.Name]; on == ok {
matchedLabels = append(matchedLabels, v)
}
}
return matchedLabels
}
// Hash returns a hash value for the label set.
func (ls Labels) Hash() uint64 {
b := make([]byte, 0, 1024)

104
pkg/labels/labels_test.go Normal file
View file

@ -0,0 +1,104 @@
// Copyright 2019 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package labels
import (
"testing"
)
func TestLabels_MatchLabels(t *testing.T) {
labels := Labels{
{
Name: "__name__",
Value: "ALERTS",
},
{
Name: "alertname",
Value: "HTTPRequestRateLow",
},
{
Name: "alertstate",
Value: "pending",
},
{
Name: "instance",
Value: "0",
},
{
Name: "job",
Value: "app-server",
},
{
Name: "severity",
Value: "critical",
},
}
providedNames := []string{
"__name__",
"alertname",
"alertstate",
"instance",
}
got := labels.MatchLabels(true, providedNames...)
expected := Labels{
{
Name: "__name__",
Value: "ALERTS",
},
{
Name: "alertname",
Value: "HTTPRequestRateLow",
},
{
Name: "alertstate",
Value: "pending",
},
{
Name: "instance",
Value: "0",
},
}
assertSlice(t, got, expected)
// Now try with 'on' set to false.
got = labels.MatchLabels(false, providedNames...)
expected = Labels{
{
Name: "job",
Value: "app-server",
},
{
Name: "severity",
Value: "critical",
},
}
assertSlice(t, got, expected)
}
func assertSlice(t *testing.T, got, expected Labels) {
if len(expected) != len(got) {
t.Errorf("expected the length of matched label names to be %d, but got %d", len(expected), len(got))
}
for i, expectedLabel := range expected {
if expectedLabel.Name != got[i].Name {
t.Errorf("expected to get Label with name %s, but got %s instead", expectedLabel.Name, got[i].Name)
}
}
}

View file

@ -1434,9 +1434,16 @@ func (ev *evaluator) VectorBinop(op ItemType, lhs, rhs Vector, matching *VectorM
sig := sigf(rs.Metric)
// The rhs is guaranteed to be the 'one' side. Having multiple samples
// with the same signature means that the matching is many-to-many.
if _, found := rightSigs[sig]; found {
if duplSample, found := rightSigs[sig]; found {
// oneSide represents which side of the vector represents the 'one' in the many-to-one relationship.
oneSide := "right"
if matching.Card == CardOneToMany {
oneSide = "left"
}
matchedLabels := rs.Metric.MatchLabels(matching.On, matching.MatchingLabels...)
// Many-to-many matching not allowed.
ev.errorf("many-to-many matching not allowed: matching labels must be unique on one side")
ev.errorf("found duplicate series for the match group %s on the %s hand-side of the operation: [%s, %s]"+
";many-to-many matching not allowed: matching labels must be unique on one side", matchedLabels.String(), oneSide, rs.Metric.String(), duplSample.Metric.String())
}
rightSigs[sig] = rs
}