From aec9cd4316741645a7d439e9f67087af102fd6de Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Thu, 22 Feb 2024 17:37:43 +0200
Subject: [PATCH] lib/storage: do not pool rawRowsBlock when flushing rawRows
 to in-memory blocks

The pooled rawRowsBlock objects occupies big amounts of memory between flushes,
and the flushes are relatively rare. So it is better to don't use the pool
and to allocate rawRow blocks on demand. This should reduce the average
memory usage between flushes.
---
 lib/mergeset/table.go    |  4 +---
 lib/storage/partition.go | 32 ++++----------------------------
 2 files changed, 5 insertions(+), 31 deletions(-)

diff --git a/lib/mergeset/table.go b/lib/mergeset/table.go
index f55a4730e..9a19ffd28 100644
--- a/lib/mergeset/table.go
+++ b/lib/mergeset/table.go
@@ -255,9 +255,7 @@ func (ris *rawItemsShard) addItems(tb *Table, items [][]byte) [][]byte {
 	ris.ibs = ibs
 	ris.mu.Unlock()
 
-	if len(ibsToFlush) > 0 {
-		tb.flushBlocksToInmemoryParts(ibsToFlush, false)
-	}
+	tb.flushBlocksToInmemoryParts(ibsToFlush, false)
 
 	return tailItems
 }
diff --git a/lib/storage/partition.go b/lib/storage/partition.go
index ef5937d24..e680885ca 100644
--- a/lib/storage/partition.go
+++ b/lib/storage/partition.go
@@ -489,7 +489,7 @@ func (rrs *rawRowsShard) Len() int {
 }
 
 func (rrs *rawRowsShard) addRows(pt *partition, rows []rawRow) []rawRow {
-	var rrb *rawRowsBlock
+	var rowsToFlush []rawRow
 
 	rrs.mu.Lock()
 	if cap(rrs.rows) == 0 {
@@ -499,8 +499,8 @@ func (rrs *rawRowsShard) addRows(pt *partition, rows []rawRow) []rawRow {
 	rrs.rows = rrs.rows[:len(rrs.rows)+n]
 	rows = rows[n:]
 	if len(rows) > 0 {
-		rrb = getRawRowsBlock()
-		rrb.rows, rrs.rows = rrs.rows, rrb.rows
+		rowsToFlush = rrs.rows
+		rrs.rows = newRawRows()
 		n = copy(rrs.rows[:cap(rrs.rows)], rows)
 		rrs.rows = rrs.rows[:n]
 		rows = rows[n:]
@@ -508,40 +508,16 @@ func (rrs *rawRowsShard) addRows(pt *partition, rows []rawRow) []rawRow {
 	}
 	rrs.mu.Unlock()
 
-	if rrb != nil {
-		pt.flushRowsToInmemoryParts(rrb.rows)
-		putRawRowsBlock(rrb)
-	}
+	pt.flushRowsToInmemoryParts(rowsToFlush)
 
 	return rows
 }
 
-type rawRowsBlock struct {
-	rows []rawRow
-}
-
 func newRawRows() []rawRow {
 	n := getMaxRawRowsPerShard()
 	return make([]rawRow, 0, n)
 }
 
-func getRawRowsBlock() *rawRowsBlock {
-	v := rawRowsBlockPool.Get()
-	if v == nil {
-		return &rawRowsBlock{
-			rows: newRawRows(),
-		}
-	}
-	return v.(*rawRowsBlock)
-}
-
-func putRawRowsBlock(rrb *rawRowsBlock) {
-	rrb.rows = rrb.rows[:0]
-	rawRowsBlockPool.Put(rrb)
-}
-
-var rawRowsBlockPool sync.Pool
-
 func (pt *partition) flushRowsToInmemoryParts(rows []rawRow) {
 	if len(rows) == 0 {
 		return