From c18017a9c3e4483f3ab3a0a148a57236a265dfd7 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Wed, 23 Jun 2021 14:00:06 +0300
Subject: [PATCH] app/vminsert/netstorage: sort the `-storageNode` list passed
 to `vminsert` nodes

This should reduce resource usage (CPU, RAM, disk IO) at vmstorage nodes
if the addresses of vmstorage nodes are passed in random order to vminsert nodes.
---
 app/vminsert/netstorage/netstorage.go | 6 ++++++
 docs/CHANGELOG.md                     | 1 +
 2 files changed, 7 insertions(+)

diff --git a/app/vminsert/netstorage/netstorage.go b/app/vminsert/netstorage/netstorage.go
index 1fdf001093..70c678d765 100644
--- a/app/vminsert/netstorage/netstorage.go
+++ b/app/vminsert/netstorage/netstorage.go
@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
+	"sort"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -400,6 +401,11 @@ func InitStorageNodes(addrs []string) {
 		logger.Panicf("BUG: too much addresses: %d; max supported %d addresses", len(addrs), 255)
 	}
 
+	// Sort addrs in order to guarantee identical series->vmstorage mapping across all the vminsert nodes.
+	addrsCopy := append([]string{}, addrs...)
+	sort.Strings(addrsCopy)
+	addrs = addrsCopy
+
 	storageNodes = storageNodes[:0]
 	for _, addr := range addrs {
 		sn := &storageNode{
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 3b7efab644..26dece6956 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -15,6 +15,7 @@ sort: 15
 * FEATURE: vmagent: support generic auth configs in `consul_sd_configs` in the same way as Prometheus 2.28 does. See [this issue](https://github.com/prometheus/prometheus/issues/8924) for details.
 * FEATURE: [vmctl](https://docs.victoriametrics.com/vmctl.html): limit the number of samples per each imported JSON line. This should limit the memory usage at VictoriaMetrics side when importing time series with big number of samples.
 * FEATURE: vmselect: log slow queries across all the `/api/v1/*` handlers (aka [Prometheus query API](https://prometheus.io/docs/prometheus/latest/querying/api)) if their execution duration exceeds `-search.logSlowQueryDuration`. This should simplify debugging slow requests to such handlers as `/api/v1/labels` or `/api/v1/series` additionally to `/api/v1/query` and `/api/v1/query_range`, which were logged in the previous releases.
+* FEATURE: vminsert: sort the `-storageNode` list in order to guarantee the identical `series -> vmstorage` mapping across all the `vminsert` nodes. This should reduce resource usage (RAM, CPU and disk IO) at `vmstorage` nodes if `vmstorage` addresses are passed in random order to `vminsert` nodes.
 
 * BUGFIX: prevent from adding new samples to deleted time series after the rotation of the inverted index (the rotation is performed once per `-retentionPeriod`). See [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1347#issuecomment-861232136) for details.
 * BUGFIX: vmstorage: reduce high disk write IO usage on systems with big number of CPU cores. The issue has been introduced in the release [v1.59.0](#v1590). See [this commit](aa9b56a046b6ae8083fa659df35dd5e994bf9115) and [this comment](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1338#issuecomment-863046999) for details.