From dcac849c1ffb4909e745cf51634fe1849b7278aa Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Thu, 20 May 2021 02:12:36 +0300
Subject: [PATCH] app/vmagent/remotewrite: sort labels before sending the
 series to per-remoteWrite.url queues

---
 app/vmagent/remotewrite/pendingseries.go |  1 -
 app/vmagent/remotewrite/remotewrite.go   | 16 ++++++++
 app/vmagent/remotewrite/sort_labels.go   | 51 ------------------------
 3 files changed, 16 insertions(+), 52 deletions(-)
 delete mode 100644 app/vmagent/remotewrite/sort_labels.go

diff --git a/app/vmagent/remotewrite/pendingseries.go b/app/vmagent/remotewrite/pendingseries.go
index 05c5453315..a5dff6c7d6 100644
--- a/app/vmagent/remotewrite/pendingseries.go
+++ b/app/vmagent/remotewrite/pendingseries.go
@@ -128,7 +128,6 @@ func (wr *writeRequest) reset() {
 }
 
 func (wr *writeRequest) flush() {
-	sortLabelsIfNeeded(wr.tss)
 	wr.wr.Timeseries = wr.tss
 	wr.adjustSampleValues()
 	atomic.StoreUint64(&wr.lastFlushTime, fasttime.UnixTimestamp())
diff --git a/app/vmagent/remotewrite/remotewrite.go b/app/vmagent/remotewrite/remotewrite.go
index 09ec041028..de07aa7b48 100644
--- a/app/vmagent/remotewrite/remotewrite.go
+++ b/app/vmagent/remotewrite/remotewrite.go
@@ -13,6 +13,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/persistentqueue"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/procutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
 	"github.com/VictoriaMetrics/metrics"
 	xxhash "github.com/cespare/xxhash/v2"
 )
@@ -38,6 +39,10 @@ var (
 		"Examples: -remoteWrite.roundDigits=2 would round 1.236 to 1.24, while -remoteWrite.roundDigits=-1 would round 126.78 to 130. "+
 		"By default digits rounding is disabled. Set it to 100 for disabling it for a particular remote storage. "+
 		"This option may be used for improving data compression for the stored metrics")
+	sortLabels = flag.Bool("sortLabels", false, `Whether to sort labels for incoming samples before writing them to all the configured remote storage systems. `+
+		`This may be needed for reducing memory usage at remote storage when the order of labels in incoming samples is random. `+
+		`For example, if m{k1="v1",k2="v2"} may be sent as m{k2="v2",k1="v1"}`+
+		`Enabled sorting for labels can slow down ingestion performance a bit`)
 )
 
 var rwctxs []*remoteWriteCtx
@@ -173,6 +178,7 @@ func Push(wr *prompbmarshal.WriteRequest) {
 			tssBlock = rctx.applyRelabeling(tssBlock, labelsGlobal, pcsGlobal)
 			globalRelabelMetricsDropped.Add(tssBlockLen - len(tssBlock))
 		}
+		sortLabelsIfNeeded(tssBlock)
 		for _, rwctx := range rwctxs {
 			rwctx.Push(tssBlock)
 		}
@@ -185,6 +191,16 @@ func Push(wr *prompbmarshal.WriteRequest) {
 	}
 }
 
+// sortLabelsIfNeeded sorts labels if -sortLabels command-line flag is set.
+func sortLabelsIfNeeded(tss []prompbmarshal.TimeSeries) {
+	if !*sortLabels {
+		return
+	}
+	for i := range tss {
+		promrelabel.SortLabels(tss[i].Labels)
+	}
+}
+
 var globalRelabelMetricsDropped = metrics.NewCounter("vmagent_remotewrite_global_relabel_metrics_dropped_total")
 
 type remoteWriteCtx struct {
diff --git a/app/vmagent/remotewrite/sort_labels.go b/app/vmagent/remotewrite/sort_labels.go
deleted file mode 100644
index e9ec252bd9..0000000000
--- a/app/vmagent/remotewrite/sort_labels.go
+++ /dev/null
@@ -1,51 +0,0 @@
-package remotewrite
-
-import (
-	"flag"
-	"sort"
-	"sync"
-
-	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
-)
-
-var sortLabels = flag.Bool("sortLabels", false, `Whether to sort labels for incoming samples before writing them to all the configured remote storage systems. `+
-	`This may be needed for reducing memory usage at remote storage when the order of labels in incoming samples is random. `+
-	`For example, if m{k1="v1",k2="v2"} may be sent as m{k2="v2",k1="v1"}`+
-	`Enabled sorting for labels can slow down ingestion performance a bit`)
-
-// sortLabelsIfNeeded sorts labels if -sortLabels command-line flag is set.
-func sortLabelsIfNeeded(tss []prompbmarshal.TimeSeries) {
-	if !*sortLabels {
-		return
-	}
-	// The slc is used for avoiding memory allocation when passing labels to sort.Sort.
-	slc := sortLabelsCtxPool.Get().(*sortLabelsCtx)
-	for i := range tss {
-		slc.labels = tss[i].Labels
-		sort.Sort(&slc.labels)
-	}
-	slc.labels = nil
-	sortLabelsCtxPool.Put(slc)
-}
-
-type sortLabelsCtx struct {
-	labels sortedLabels
-}
-
-var sortLabelsCtxPool = &sync.Pool{
-	New: func() interface{} {
-		return &sortLabelsCtx{}
-	},
-}
-
-type sortedLabels []prompbmarshal.Label
-
-func (sl *sortedLabels) Len() int { return len(*sl) }
-func (sl *sortedLabels) Less(i, j int) bool {
-	a := *sl
-	return a[i].Name < a[j].Name
-}
-func (sl *sortedLabels) Swap(i, j int) {
-	a := *sl
-	a[i], a[j] = a[j], a[i]
-}