VictoriaMetrics/lib/mergeset/inmemory_part.go
Aliaksandr Valialkin f4e466955d
lib/mergeset: move storageBlock from inmemoryPart to a sync.Pool
The lifetime of storageBlock is much shorter comparing to the lifetime of inmemoryPart,
so sync.Pool usage should reduce overall memory usage and improve performance
because of better locality of reference when marshaling inmemoryBlock to inmemoryPart.

https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2247
2022-03-03 17:12:25 +02:00

121 lines
3.8 KiB
Go

package mergeset
import (
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/cgroup"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
)
type inmemoryPart struct {
ph partHeader
bh blockHeader
mr metaindexRow
unpackedIndexBlockBuf []byte
packedIndexBlockBuf []byte
unpackedMetaindexBuf []byte
packedMetaindexBuf []byte
metaindexData bytesutil.ByteBuffer
indexData bytesutil.ByteBuffer
itemsData bytesutil.ByteBuffer
lensData bytesutil.ByteBuffer
}
func (mp *inmemoryPart) Reset() {
mp.ph.Reset()
mp.bh.Reset()
mp.mr.Reset()
mp.unpackedIndexBlockBuf = mp.unpackedIndexBlockBuf[:0]
mp.packedIndexBlockBuf = mp.packedIndexBlockBuf[:0]
mp.unpackedMetaindexBuf = mp.unpackedMetaindexBuf[:0]
mp.packedMetaindexBuf = mp.packedMetaindexBuf[:0]
mp.metaindexData.Reset()
mp.indexData.Reset()
mp.itemsData.Reset()
mp.lensData.Reset()
}
// Init initializes mp from ib.
func (mp *inmemoryPart) Init(ib *inmemoryBlock) {
mp.Reset()
sb := getStorageBlock()
defer putStorageBlock(sb)
// Use the minimum possible compressLevel for compressing inmemoryPart,
// since it will be merged into file part soon.
// See https://github.com/facebook/zstd/releases/tag/v1.3.4 for details about negative compression level
compressLevel := -5
mp.bh.firstItem, mp.bh.commonPrefix, mp.bh.itemsCount, mp.bh.marshalType = ib.MarshalUnsortedData(sb, mp.bh.firstItem[:0], mp.bh.commonPrefix[:0], compressLevel)
mp.ph.itemsCount = uint64(len(ib.items))
mp.ph.blocksCount = 1
mp.ph.firstItem = append(mp.ph.firstItem[:0], ib.items[0].String(ib.data)...)
mp.ph.lastItem = append(mp.ph.lastItem[:0], ib.items[len(ib.items)-1].String(ib.data)...)
fs.MustWriteData(&mp.itemsData, sb.itemsData)
mp.bh.itemsBlockOffset = 0
mp.bh.itemsBlockSize = uint32(len(mp.itemsData.B))
fs.MustWriteData(&mp.lensData, sb.lensData)
mp.bh.lensBlockOffset = 0
mp.bh.lensBlockSize = uint32(len(mp.lensData.B))
mp.unpackedIndexBlockBuf = mp.bh.Marshal(mp.unpackedIndexBlockBuf[:0])
mp.packedIndexBlockBuf = encoding.CompressZSTDLevel(mp.packedIndexBlockBuf[:0], mp.unpackedIndexBlockBuf, 0)
fs.MustWriteData(&mp.indexData, mp.packedIndexBlockBuf)
mp.mr.firstItem = append(mp.mr.firstItem[:0], mp.bh.firstItem...)
mp.mr.blockHeadersCount = 1
mp.mr.indexBlockOffset = 0
mp.mr.indexBlockSize = uint32(len(mp.packedIndexBlockBuf))
mp.unpackedMetaindexBuf = mp.mr.Marshal(mp.unpackedMetaindexBuf[:0])
mp.packedMetaindexBuf = encoding.CompressZSTDLevel(mp.packedMetaindexBuf[:0], mp.unpackedMetaindexBuf, 0)
fs.MustWriteData(&mp.metaindexData, mp.packedMetaindexBuf)
}
// It is safe calling NewPart multiple times.
// It is unsafe re-using mp while the returned part is in use.
func (mp *inmemoryPart) NewPart() *part {
ph := mp.ph
size := mp.size()
p, err := newPart(&ph, "", size, mp.metaindexData.NewReader(), &mp.indexData, &mp.itemsData, &mp.lensData)
if err != nil {
logger.Panicf("BUG: cannot create a part from inmemoryPart: %s", err)
}
return p
}
func (mp *inmemoryPart) size() uint64 {
return uint64(len(mp.metaindexData.B) + len(mp.indexData.B) + len(mp.itemsData.B) + len(mp.lensData.B))
}
func getInmemoryPart() *inmemoryPart {
select {
case mp := <-mpPool:
return mp
default:
return &inmemoryPart{}
}
}
func putInmemoryPart(mp *inmemoryPart) {
mp.Reset()
select {
case mpPool <- mp:
default:
// Drop mp in order to reduce memory usage.
}
}
// Use chan instead of sync.Pool in order to reduce memory usage on systems with big number of CPU cores,
// since sync.Pool maintains per-CPU pool of inmemoryPart objects.
//
// The inmemoryPart object size can exceed 64KB, so it is better to use chan instead of sync.Pool for reducing memory usage.
var mpPool = make(chan *inmemoryPart, cgroup.AvailableCPUs())