mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-15 00:13:30 +01:00
7d5c64eb7a
The main purpose of this command-line flag is to increase the lifetime of low-end flash storage with the limited number of write operations it can perform. Such flash storage is usually installed on Raspberry PI or similar appliances. For example, `-inmemoryDataFlushInterval=1h` reduces the frequency of disk write operations to up to once per hour if the ingested one-hour worth of data fits the limit for in-memory data. The in-memory data is searchable in the same way as the data stored on disk. VictoriaMetrics automatically flushes the in-memory data to disk on graceful shutdown via SIGINT signal. The in-memory data is lost on unclean shutdown (hardware power loss, OOM crash, SIGKILL). Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3337
124 lines
4.1 KiB
Go
124 lines
4.1 KiB
Go
package mergeset
|
|
|
|
import (
|
|
"fmt"
|
|
"path/filepath"
|
|
|
|
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
|
|
"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
|
|
|
|
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.metaindexData.Reset()
|
|
mp.indexData.Reset()
|
|
mp.itemsData.Reset()
|
|
mp.lensData.Reset()
|
|
}
|
|
|
|
// StoreToDisk stores mp to the given path on disk.
|
|
func (mp *inmemoryPart) StoreToDisk(path string) error {
|
|
if err := fs.MkdirAllIfNotExist(path); err != nil {
|
|
return fmt.Errorf("cannot create directory %q: %w", path, err)
|
|
}
|
|
metaindexPath := path + "/metaindex.bin"
|
|
if err := fs.WriteFileAndSync(metaindexPath, mp.metaindexData.B); err != nil {
|
|
return fmt.Errorf("cannot store metaindex: %w", err)
|
|
}
|
|
indexPath := path + "/index.bin"
|
|
if err := fs.WriteFileAndSync(indexPath, mp.indexData.B); err != nil {
|
|
return fmt.Errorf("cannot store index: %w", err)
|
|
}
|
|
itemsPath := path + "/items.bin"
|
|
if err := fs.WriteFileAndSync(itemsPath, mp.itemsData.B); err != nil {
|
|
return fmt.Errorf("cannot store items: %w", err)
|
|
}
|
|
lensPath := path + "/lens.bin"
|
|
if err := fs.WriteFileAndSync(lensPath, mp.lensData.B); err != nil {
|
|
return fmt.Errorf("cannot store lens: %w", err)
|
|
}
|
|
if err := mp.ph.WriteMetadata(path); err != nil {
|
|
return fmt.Errorf("cannot store metadata: %w", err)
|
|
}
|
|
// Sync parent directory in order to make sure the written files remain visible after hardware reset
|
|
parentDirPath := filepath.Dir(path)
|
|
fs.MustSyncPath(parentDirPath)
|
|
return nil
|
|
}
|
|
|
|
// Init initializes mp from ib.
|
|
func (mp *inmemoryPart) Init(ib *inmemoryBlock) {
|
|
mp.Reset()
|
|
|
|
// Re-use mp.itemsData and mp.lensData in sb.
|
|
// This eliminates copying itemsData and lensData from sb to mp later.
|
|
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2247
|
|
sb := &storageBlock{}
|
|
sb.itemsData = mp.itemsData.B[:0]
|
|
sb.lensData = mp.lensData.B[:0]
|
|
|
|
// 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)...)
|
|
|
|
mp.itemsData.B = sb.itemsData
|
|
mp.bh.itemsBlockOffset = 0
|
|
mp.bh.itemsBlockSize = uint32(len(mp.itemsData.B))
|
|
|
|
mp.lensData.B = sb.lensData
|
|
mp.bh.lensBlockOffset = 0
|
|
mp.bh.lensBlockSize = uint32(len(mp.lensData.B))
|
|
|
|
bb := inmemoryPartBytePool.Get()
|
|
bb.B = mp.bh.Marshal(bb.B[:0])
|
|
mp.indexData.B = encoding.CompressZSTDLevel(mp.indexData.B[:0], bb.B, compressLevel)
|
|
|
|
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.indexData.B))
|
|
bb.B = mp.mr.Marshal(bb.B[:0])
|
|
mp.metaindexData.B = encoding.CompressZSTDLevel(mp.metaindexData.B[:0], bb.B, compressLevel)
|
|
inmemoryPartBytePool.Put(bb)
|
|
}
|
|
|
|
var inmemoryPartBytePool bytesutil.ByteBufferPool
|
|
|
|
// 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 {
|
|
size := mp.size()
|
|
p, err := newPart(&mp.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(cap(mp.metaindexData.B) + cap(mp.indexData.B) + cap(mp.itemsData.B) + cap(mp.lensData.B))
|
|
}
|