From 7345567c293a54274b9900c0c3c19007dc22f265 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Mon, 22 Jan 2024 22:15:08 +0200
Subject: [PATCH] app/vmselect/netstorage: substitute pointer to blockRefs by
brssPool index at the metricName->blockRefs map
This should reduce the pressure on Go GC, since it will see lower number of pointers.
This change has been extracted from https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5527
---
app/vmselect/netstorage/netstorage.go | 32 +++++++++++++++++----------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/app/vmselect/netstorage/netstorage.go b/app/vmselect/netstorage/netstorage.go
index 34dc4c4956..da4468f5ad 100644
--- a/app/vmselect/netstorage/netstorage.go
+++ b/app/vmselect/netstorage/netstorage.go
@@ -1172,8 +1172,7 @@ func ProcessSearchQuery(qt *querytracer.Tracer, sq *storage.SearchQuery, deadlin
brsPrealloc [4]blockRef
brs []blockRef
}
- m := make(map[string]*blockRefs, maxSeriesCount)
- orderedMetricNames := make([]string, 0, maxSeriesCount)
+
blocksRead := 0
samples := 0
tbf := getTmpBlocksFile()
@@ -1184,9 +1183,16 @@ func ProcessSearchQuery(qt *querytracer.Tracer, sq *storage.SearchQuery, deadlin
// when constructing metricName string from byte slice.
var metricNamesBuf []byte
- // brssBuf is used for holding all the blockRefs objects across all the loaded time series.
+ // brssPool is used for holding all the blockRefs objects across all the loaded time series.
// It should reduce pressure on Go GC by reducing the number of blockRefs allocations.
- var brssBuf []blockRefs
+ brssPool := make([]blockRefs, 0, maxSeriesCount)
+
+ // m maps from metricName to the index of blockRefs inside brssPool
+ m := make(map[string]int, maxSeriesCount)
+
+ // orderedMetricNames contains the list of loaded unique metric names
+ // in the load order. This order is important for triggering sequential data reading.
+ orderedMetricNames := make([]string, 0, maxSeriesCount)
for sr.NextMetricBlock() {
blocksRead++
@@ -1210,16 +1216,18 @@ func ProcessSearchQuery(qt *querytracer.Tracer, sq *storage.SearchQuery, deadlin
return nil, fmt.Errorf("cannot write %d bytes to temporary file: %w", len(buf), err)
}
metricName := sr.MetricBlockRef.MetricName
- brs := m[string(metricName)]
- if brs == nil {
- if cap(brssBuf) > len(brssBuf) {
- brssBuf = brssBuf[:len(brssBuf)+1]
+ brsIdx, ok := m[string(metricName)]
+ if !ok {
+ if cap(brssPool) > len(brssPool) {
+ brssPool = brssPool[:len(brssPool)+1]
} else {
- brssBuf = append(brssBuf, blockRefs{})
+ brssPool = append(brssPool, blockRefs{})
}
- brs = &brssBuf[len(brssBuf)-1]
+ brsIdx = len(brssPool) - 1
+ brs := &brssPool[brsIdx]
brs.brs = brs.brsPrealloc[:0]
}
+ brs := &brssPool[brsIdx]
brs.brs = append(brs.brs, blockRef{
partRef: br.PartRef(),
addr: addr,
@@ -1230,7 +1238,7 @@ func ProcessSearchQuery(qt *querytracer.Tracer, sq *storage.SearchQuery, deadlin
metricNameStr := bytesutil.ToUnsafeString(metricNamesBuf[metricNamesBufLen:])
orderedMetricNames = append(orderedMetricNames, metricNameStr)
- m[metricNameStr] = brs
+ m[metricNameStr] = brsIdx
}
}
if err := sr.Error(); err != nil {
@@ -1255,7 +1263,7 @@ func ProcessSearchQuery(qt *querytracer.Tracer, sq *storage.SearchQuery, deadlin
for i, metricName := range orderedMetricNames {
pts[i] = packedTimeseries{
metricName: metricName,
- brs: m[metricName].brs,
+ brs: brssPool[m[metricName]].brs,
}
}
rss.packedTimeseries = pts