From b38edec7ee26db0008ea1020a3e6d142baff0dd1 Mon Sep 17 00:00:00 2001
From: Roman Khavronenko <hagen1778@gmail.com>
Date: Sat, 15 May 2021 11:25:57 +0100
Subject: [PATCH] vmalert: use stringified label keys for duplicates map in
recroding rules (#1301)
duplicates map helps to determine wheter extra labels has overriden
labels which make time series unique. It was using a sorted hashed
labels sequence as a key. But hashing algorithm could have collisions,
so it is more convenient to not use hashing at all.
Log message for recording rules duplicates was improved as well.
https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1293
---
app/vmalert/recording.go | 37 +++++++++++++++++++++----------------
1 file changed, 21 insertions(+), 16 deletions(-)
diff --git a/app/vmalert/recording.go b/app/vmalert/recording.go
index fbdeb7d59a..5e00c34db3 100644
--- a/app/vmalert/recording.go
+++ b/app/vmalert/recording.go
@@ -3,8 +3,8 @@ package main
import (
"context"
"fmt"
- "hash/fnv"
"sort"
+ "strings"
"sync"
"time"
@@ -103,33 +103,38 @@ func (rr *RecordingRule) Exec(ctx context.Context, series bool) ([]prompbmarshal
return nil, fmt.Errorf("failed to execute query %q: %w", rr.Expr, err)
}
- duplicates := make(map[uint64]prompbmarshal.TimeSeries, len(qMetrics))
+ duplicates := make(map[string]struct{}, len(qMetrics))
var tss []prompbmarshal.TimeSeries
for _, r := range qMetrics {
ts := rr.toTimeSeries(r, time.Unix(r.Timestamp, 0))
- h := hashTimeSeries(ts)
- if _, ok := duplicates[h]; ok {
+ key := stringifyLabels(ts)
+ if _, ok := duplicates[key]; ok {
rr.lastExecError = errDuplicate
- return nil, errDuplicate
+ return nil, fmt.Errorf("original metric %v; resulting labels %q: %w", r, key, errDuplicate)
}
- duplicates[h] = ts
+ duplicates[key] = struct{}{}
tss = append(tss, ts)
}
return tss, nil
}
-func hashTimeSeries(ts prompbmarshal.TimeSeries) uint64 {
- hash := fnv.New64a()
+func stringifyLabels(ts prompbmarshal.TimeSeries) string {
labels := ts.Labels
- sort.Slice(labels, func(i, j int) bool {
- return labels[i].Name < labels[j].Name
- })
- for _, l := range labels {
- hash.Write([]byte(l.Name))
- hash.Write([]byte(l.Value))
- hash.Write([]byte("\xff"))
+ if len(labels) > 1 {
+ sort.Slice(labels, func(i, j int) bool {
+ return labels[i].Name < labels[j].Name
+ })
}
- return hash.Sum64()
+ b := strings.Builder{}
+ for i, l := range labels {
+ b.WriteString(l.Name)
+ b.WriteString("=")
+ b.WriteString(l.Value)
+ if i != len(labels)-1 {
+ b.WriteString(",")
+ }
+ }
+ return b.String()
}
func (rr *RecordingRule) toTimeSeries(m datasource.Metric, timestamp time.Time) prompbmarshal.TimeSeries {