From b0c1f3d819401841cebc06f560d09607cf5ece93 Mon Sep 17 00:00:00 2001
From: Roman Khavronenko <roman@victoriametrics.com>
Date: Tue, 14 May 2024 14:43:39 +0200
Subject: [PATCH] app/vmalert/rule: reduce number of allocations for
getStaleSeries fn (#6269)
MIME-Version: 1.0
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Allocations are reduced by re-using the byte buffer when converting
labels to string keys.
```
name old allocs/op new allocs/op delta
GetStaleSeries-10 703 ± 0% 203 ± 0% ~ (p=1.000 n=1+1)
```
Signed-off-by: hagen1778 <roman@victoriametrics.com>
---
app/vmalert/rule/group.go | 34 ++++++++++++++-----------
app/vmalert/rule/group_timing_test.go | 36 +++++++++++++++++++++++++++
app/vmalert/rule/test_helpers.go | 2 +-
3 files changed, 57 insertions(+), 15 deletions(-)
create mode 100644 app/vmalert/rule/group_timing_test.go
diff --git a/app/vmalert/rule/group.go b/app/vmalert/rule/group.go
index f4e6cd0ddb..520039d71f 100644
--- a/app/vmalert/rule/group.go
+++ b/app/vmalert/rule/group.go
@@ -9,10 +9,11 @@ import (
"hash/fnv"
"net/url"
"strconv"
- "strings"
"sync"
"time"
+ "github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
+
"github.com/cheggaaa/pb/v3"
"github.com/VictoriaMetrics/VictoriaMetrics/app/vmalert/config"
@@ -724,13 +725,19 @@ func (e *executor) exec(ctx context.Context, r Rule, ts time.Time, resolveDurati
return errGr.Err()
}
+var bbPool bytesutil.ByteBufferPool
+
// getStaleSeries checks whether there are stale series from previously sent ones.
func (e *executor) getStaleSeries(r Rule, tss []prompbmarshal.TimeSeries, timestamp time.Time) []prompbmarshal.TimeSeries {
+ bb := bbPool.Get()
+ defer bbPool.Put(bb)
+
ruleLabels := make(map[string][]prompbmarshal.Label, len(tss))
for _, ts := range tss {
- // convert labels to strings so we can compare with previously sent series
- key := labelsToString(ts.Labels)
- ruleLabels[key] = ts.Labels
+ // convert labels to strings, so we can compare with previously sent series
+ bb.B = labelsToString(bb.B, ts.Labels)
+ ruleLabels[string(bb.B)] = ts.Labels
+ bb.Reset()
}
rID := r.ID()
@@ -776,21 +783,20 @@ func (e *executor) purgeStaleSeries(activeRules []Rule) {
e.previouslySentSeriesToRWMu.Unlock()
}
-func labelsToString(labels []prompbmarshal.Label) string {
- var b strings.Builder
- b.WriteRune('{')
+func labelsToString(dst []byte, labels []prompbmarshal.Label) []byte {
+ dst = append(dst, '{')
for i, label := range labels {
if len(label.Name) == 0 {
- b.WriteString("__name__")
+ dst = append(dst, "__name__"...)
} else {
- b.WriteString(label.Name)
+ dst = append(dst, label.Name...)
}
- b.WriteRune('=')
- b.WriteString(strconv.Quote(label.Value))
+ dst = append(dst, '=')
+ dst = strconv.AppendQuote(dst, label.Value)
if i < len(labels)-1 {
- b.WriteRune(',')
+ dst = append(dst, ',')
}
}
- b.WriteRune('}')
- return b.String()
+ dst = append(dst, '}')
+ return dst
}
diff --git a/app/vmalert/rule/group_timing_test.go b/app/vmalert/rule/group_timing_test.go
new file mode 100644
index 0000000000..c233ed34da
--- /dev/null
+++ b/app/vmalert/rule/group_timing_test.go
@@ -0,0 +1,36 @@
+package rule
+
+import (
+ "fmt"
+ "testing"
+ "time"
+
+ "github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+)
+
+func BenchmarkGetStaleSeries(b *testing.B) {
+ ts := time.Now()
+ n := 100
+ payload := make([]prompbmarshal.TimeSeries, n)
+ for i := 0; i < n; i++ {
+ s := fmt.Sprintf("%d", i)
+ labels := toPromLabels(b,
+ "__name__", "foo", ""+
+ "instance", s,
+ "job", s,
+ "state", s,
+ )
+ payload = append(payload, newTimeSeriesPB([]float64{1}, []int64{ts.Unix()}, labels))
+ }
+
+ e := &executor{
+ previouslySentSeriesToRW: make(map[uint64]map[string][]prompbmarshal.Label),
+ }
+ ar := &AlertingRule{RuleID: 1}
+
+ b.ResetTimer()
+ b.ReportAllocs()
+ for i := 0; i < b.N; i++ {
+ e.getStaleSeries(ar, payload, ts)
+ }
+}
diff --git a/app/vmalert/rule/test_helpers.go b/app/vmalert/rule/test_helpers.go
index dcf23dc768..9373e2b814 100644
--- a/app/vmalert/rule/test_helpers.go
+++ b/app/vmalert/rule/test_helpers.go
@@ -95,7 +95,7 @@ func metricWithLabels(t *testing.T, labels ...string) datasource.Metric {
return m
}
-func toPromLabels(t *testing.T, labels ...string) []prompbmarshal.Label {
+func toPromLabels(t testing.TB, labels ...string) []prompbmarshal.Label {
t.Helper()
if len(labels) == 0 || len(labels)%2 != 0 {
t.Fatalf("expected to get even number of labels")