app/{vminsert,vmagent}: improve data ingestion speed over a single connection

Process data obtianed from a single connection on all the available CPU cores.

app/vmagent/main.go

@@ -29,6 +29,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/procutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/writeconcurrencylimiter"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -81,6 +82,7 @@ func main() {
 	logger.Infof("starting vmagent at %q...", *httpListenAddr)
 	startTime := time.Now()
 	remotewrite.Init()
+	common.StartUnmarshalWorkers()
 	writeconcurrencylimiter.Init()
 	if len(*influxListenAddr) > 0 {
 		influxServer = influxserver.MustStart(*influxListenAddr, influx.InsertHandlerForReader)
@@ -128,6 +130,7 @@ func main() {
 	if len(*opentsdbHTTPListenAddr) > 0 {
 		opentsdbhttpServer.MustStop()
 	}
+	common.StopUnmarshalWorkers()
 	remotewrite.Stop()
 
 	logger.Infof("successfully stopped vmagent in %.3f seconds", time.Since(startTime).Seconds())

app/vminsert/main.go

@@ -25,6 +25,7 @@ import (
 	opentsdbhttpserver "github.com/VictoriaMetrics/VictoriaMetrics/lib/ingestserver/opentsdbhttp"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/procutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/promscrape"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/writeconcurrencylimiter"
 	"github.com/VictoriaMetrics/metrics"
@@ -52,7 +53,7 @@ var (
 func Init() {
 	relabel.Init()
 	storage.SetMaxLabelsPerTimeseries(*maxLabelsPerTimeseries)
-
+	common.StartUnmarshalWorkers()
 	writeconcurrencylimiter.Init()
 	if len(*influxListenAddr) > 0 {
 		influxServer = influxserver.MustStart(*influxListenAddr, influx.InsertHandlerForReader)
@@ -84,6 +85,7 @@ func Stop() {
 	if len(*opentsdbHTTPListenAddr) > 0 {
 		opentsdbhttpServer.MustStop()
 	}
+	common.StopUnmarshalWorkers()
 }
 
 // RequestHandler is a handler for Prometheus remote storage write API

lib/protoparser/common/unmarshal_work.go

@@ -0,0 +1,53 @@
+package common
+
+import (
+	"runtime"
+	"sync"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+)
+
+// ScheduleUnmarshalWork schedules uw to run in the worker pool.
+//
+// It is expected that StartUnmarshalWorkers is already called.
+func ScheduleUnmarshalWork(uw UnmarshalWork) {
+	unmarshalWorkCh <- uw
+}
+
+// UnmarshalWork is a unit of unmarshal work.
+type UnmarshalWork interface {
+	// Unmarshal must implement CPU-bound unmarshal work.
+	Unmarshal()
+}
+
+// StartUnmarshalWorkers starts unmarshal workers.
+func StartUnmarshalWorkers() {
+	if unmarshalWorkCh != nil {
+		logger.Panicf("BUG: it looks like startUnmarshalWorkers() has been alread called without stopUnmarshalWorkers()")
+	}
+	gomaxprocs := runtime.GOMAXPROCS(-1)
+	unmarshalWorkCh = make(chan UnmarshalWork, 2*gomaxprocs)
+	unmarshalWorkersWG.Add(gomaxprocs)
+	for i := 0; i < gomaxprocs; i++ {
+		go func() {
+			defer unmarshalWorkersWG.Done()
+			for uw := range unmarshalWorkCh {
+				uw.Unmarshal()
+			}
+		}()
+	}
+}
+
+// StopUnmarshalWorkers stops unmarshal workers.
+//
+// No more calles to ScheduleUnmarshalWork are allowed after callsing stopUnmarshalWorkers
+func StopUnmarshalWorkers() {
+	close(unmarshalWorkCh)
+	unmarshalWorkersWG.Wait()
+	unmarshalWorkCh = nil
+}
+
+var (
+	unmarshalWorkCh    chan UnmarshalWork
+	unmarshalWorkersWG sync.WaitGroup
+)

lib/protoparser/csvimport/streamparser.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -43,15 +44,17 @@ func ParseStream(req *http.Request, callback func(rows []Row) error) error {
 	}
 	ctx := getStreamContext(r)
 	defer putStreamContext(ctx)
-	for ctx.Read(cds) {
-		if err := callback(ctx.Rows.Rows); err != nil {
-			return err
-		}
+	for ctx.Read() {
+		uw := getUnmarshalWork()
+		uw.callback = callback
+		uw.cds = cds
+		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
 }
 
-func (ctx *streamContext) Read(cds []ColumnDescriptor) bool {
+func (ctx *streamContext) Read() bool {
 	readCalls.Inc()
 	if ctx.err != nil {
 		return false
@@ -64,28 +67,6 @@ func (ctx *streamContext) Read(cds []ColumnDescriptor) bool {
 		}
 		return false
 	}
-	ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf), cds)
-	rowsRead.Add(len(ctx.Rows.Rows))
-
-	rows := ctx.Rows.Rows
-
-	// Set missing timestamps
-	currentTs := time.Now().UnixNano() / 1e6
-	for i := range rows {
-		row := &rows[i]
-		if row.Timestamp == 0 {
-			row.Timestamp = currentTs
-		}
-	}
-
-	// Trim timestamps if required.
-	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1 {
-		for i := range rows {
-			row := &rows[i]
-			row.Timestamp -= row.Timestamp % tsTrim
-		}
-	}
-
 	return true
 }
 
@@ -96,7 +77,6 @@ var (
 )
 
 type streamContext struct {
-	Rows    Rows
 	br      *bufio.Reader
 	reqBuf  []byte
 	tailBuf []byte
@@ -111,7 +91,6 @@ func (ctx *streamContext) Error() error {
 }
 
 func (ctx *streamContext) reset() {
-	ctx.Rows.Reset()
 	ctx.br.Reset(nil)
 	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
@@ -146,3 +125,63 @@ func putStreamContext(ctx *streamContext) {
 
 var streamContextPool sync.Pool
 var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))
+
+type unmarshalWork struct {
+	rows     Rows
+	callback func(rows []Row) error
+	cds      []ColumnDescriptor
+	reqBuf   []byte
+}
+
+func (uw *unmarshalWork) reset() {
+	uw.rows.Reset()
+	uw.callback = nil
+	uw.cds = nil
+	uw.reqBuf = uw.reqBuf[:0]
+}
+
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	uw.rows.Unmarshal(bytesutil.ToUnsafeString(uw.reqBuf), uw.cds)
+	rows := uw.rows.Rows
+	rowsRead.Add(len(rows))
+
+	// Set missing timestamps
+	currentTs := time.Now().UnixNano() / 1e6
+	for i := range rows {
+		row := &rows[i]
+		if row.Timestamp == 0 {
+			row.Timestamp = currentTs
+		}
+	}
+
+	// Trim timestamps if required.
+	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1 {
+		for i := range rows {
+			row := &rows[i]
+			row.Timestamp -= row.Timestamp % tsTrim
+		}
+	}
+
+	if err := uw.callback(rows); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
+func getUnmarshalWork() *unmarshalWork {
+	v := unmarshalWorkPool.Get()
+	if v == nil {
+		return &unmarshalWork{}
+	}
+	return v.(*unmarshalWork)
+}
+
+func putUnmarshalWork(uw *unmarshalWork) {
+	uw.reset()
+	unmarshalWorkPool.Put(uw)
+}
+
+var unmarshalWorkPool sync.Pool

lib/protoparser/graphite/parser_test.go

@@ -185,12 +185,25 @@ func Test_streamContext_Read(t *testing.T) {
 	f := func(s string, rowsExpected *Rows) {
 		t.Helper()
 		ctx := getStreamContext(strings.NewReader(s))
-		ctx.Read()
-		if len(ctx.Rows.Rows) != len(rowsExpected.Rows) {
-			t.Fatalf("different len of expected rows;\ngot\n%+v;\nwant\n%+v", ctx.Rows, rowsExpected.Rows)
+		if !ctx.Read() {
+			t.Fatalf("expecting successful read")
 		}
-		if !reflect.DeepEqual(ctx.Rows.Rows, rowsExpected.Rows) {
-			t.Fatalf("unexpected rows;\ngot\n%+v;\nwant\n%+v", ctx.Rows.Rows, rowsExpected.Rows)
+		uw := getUnmarshalWork()
+		callbackCalls := 0
+		uw.callback = func(rows []Row) error {
+			callbackCalls++
+			if len(rows) != len(rowsExpected.Rows) {
+				t.Fatalf("different len of expected rows;\ngot\n%+v;\nwant\n%+v", rows, rowsExpected.Rows)
+			}
+			if !reflect.DeepEqual(rows, rowsExpected.Rows) {
+				t.Fatalf("unexpected rows;\ngot\n%+v;\nwant\n%+v", rows, rowsExpected.Rows)
+			}
+			return nil
+		}
+		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		uw.Unmarshal()
+		if callbackCalls != 1 {
+			t.Fatalf("unexpected number of callback calls; got %d; want 1", callbackCalls)
 		}
 	}
 

lib/protoparser/graphite/streamparser.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -30,9 +31,10 @@ func ParseStream(r io.Reader, callback func(rows []Row) error) error {
 	defer putStreamContext(ctx)
 
 	for ctx.Read() {
-		if err := callback(ctx.Rows.Rows); err != nil {
-			return err
-		}
+		uw := getUnmarshalWork()
+		uw.callback = callback
+		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
 }
@@ -50,38 +52,10 @@ func (ctx *streamContext) Read() bool {
 		}
 		return false
 	}
-	ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf))
-	rowsRead.Add(len(ctx.Rows.Rows))
-
-	rows := ctx.Rows.Rows
-
-	// Fill missing timestamps with the current timestamp rounded to seconds.
-	currentTimestamp := int64(fasttime.UnixTimestamp())
-	for i := range rows {
-		r := &rows[i]
-		if r.Timestamp == 0 || r.Timestamp == -1 {
-			r.Timestamp = currentTimestamp
-		}
-	}
-
-	// Convert timestamps from seconds to milliseconds.
-	for i := range rows {
-		rows[i].Timestamp *= 1e3
-	}
-
-	// Trim timestamps if required.
-	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1000 {
-		for i := range rows {
-			row := &rows[i]
-			row.Timestamp -= row.Timestamp % tsTrim
-		}
-	}
-
 	return true
 }
 
 type streamContext struct {
-	Rows    Rows
 	br      *bufio.Reader
 	reqBuf  []byte
 	tailBuf []byte
@@ -96,7 +70,6 @@ func (ctx *streamContext) Error() error {
 }
 
 func (ctx *streamContext) reset() {
-	ctx.Rows.Reset()
 	ctx.br.Reset(nil)
 	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
@@ -137,3 +110,66 @@ func putStreamContext(ctx *streamContext) {
 
 var streamContextPool sync.Pool
 var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))
+
+type unmarshalWork struct {
+	rows     Rows
+	callback func(rows []Row) error
+	reqBuf   []byte
+}
+
+func (uw *unmarshalWork) reset() {
+	uw.rows.Reset()
+	uw.callback = nil
+	uw.reqBuf = uw.reqBuf[:0]
+}
+
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	uw.rows.Unmarshal(bytesutil.ToUnsafeString(uw.reqBuf))
+	rows := uw.rows.Rows
+	rowsRead.Add(len(rows))
+
+	// Fill missing timestamps with the current timestamp rounded to seconds.
+	currentTimestamp := int64(fasttime.UnixTimestamp())
+	for i := range rows {
+		r := &rows[i]
+		if r.Timestamp == 0 || r.Timestamp == -1 {
+			r.Timestamp = currentTimestamp
+		}
+	}
+
+	// Convert timestamps from seconds to milliseconds.
+	for i := range rows {
+		rows[i].Timestamp *= 1e3
+	}
+
+	// Trim timestamps if required.
+	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1000 {
+		for i := range rows {
+			row := &rows[i]
+			row.Timestamp -= row.Timestamp % tsTrim
+		}
+	}
+
+	if err := uw.callback(rows); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
+func getUnmarshalWork() *unmarshalWork {
+	v := unmarshalWorkPool.Get()
+	if v == nil {
+		return &unmarshalWork{}
+	}
+	return v.(*unmarshalWork)
+}
+
+func putUnmarshalWork(uw *unmarshalWork) {
+	uw.reset()
+	unmarshalWorkPool.Put(uw)
+}
+
+var unmarshalWorkPool sync.Pool

lib/protoparser/influx/streamparser.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -53,15 +54,18 @@ func ParseStream(r io.Reader, isGzipped bool, precision, db string, callback fun
 
 	ctx := getStreamContext(r)
 	defer putStreamContext(ctx)
-	for ctx.Read(tsMultiplier) {
-		if err := callback(db, ctx.Rows.Rows); err != nil {
-			return err
-		}
+	for ctx.Read() {
+		uw := getUnmarshalWork()
+		uw.callback = callback
+		uw.db = db
+		uw.tsMultiplier = tsMultiplier
+		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
 }
 
-func (ctx *streamContext) Read(tsMultiplier int64) bool {
+func (ctx *streamContext) Read() bool {
 	readCalls.Inc()
 	if ctx.err != nil {
 		return false
@@ -74,43 +78,6 @@ func (ctx *streamContext) Read(tsMultiplier int64) bool {
 		}
 		return false
 	}
-	ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf))
-	rowsRead.Add(len(ctx.Rows.Rows))
-
-	rows := ctx.Rows.Rows
-
-	// Adjust timestamps according to tsMultiplier
-	currentTs := time.Now().UnixNano() / 1e6
-	if tsMultiplier >= 1 {
-		for i := range rows {
-			row := &rows[i]
-			if row.Timestamp == 0 {
-				row.Timestamp = currentTs
-			} else {
-				row.Timestamp /= tsMultiplier
-			}
-		}
-	} else if tsMultiplier < 0 {
-		tsMultiplier = -tsMultiplier
-		currentTs -= currentTs % tsMultiplier
-		for i := range rows {
-			row := &rows[i]
-			if row.Timestamp == 0 {
-				row.Timestamp = currentTs
-			} else {
-				row.Timestamp *= tsMultiplier
-			}
-		}
-	}
-
-	// Trim timestamps if required.
-	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1 {
-		for i := range rows {
-			row := &rows[i]
-			row.Timestamp -= row.Timestamp % tsTrim
-		}
-	}
-
 	return true
 }
 
@@ -121,7 +88,6 @@ var (
 )
 
 type streamContext struct {
-	Rows    Rows
 	br      *bufio.Reader
 	reqBuf  []byte
 	tailBuf []byte
@@ -136,7 +102,6 @@ func (ctx *streamContext) Error() error {
 }
 
 func (ctx *streamContext) reset() {
-	ctx.Rows.Reset()
 	ctx.br.Reset(nil)
 	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
@@ -171,3 +136,81 @@ func putStreamContext(ctx *streamContext) {
 
 var streamContextPool sync.Pool
 var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))
+
+type unmarshalWork struct {
+	rows         Rows
+	callback     func(db string, rows []Row) error
+	db           string
+	tsMultiplier int64
+	reqBuf       []byte
+}
+
+func (uw *unmarshalWork) reset() {
+	uw.rows.Reset()
+	uw.callback = nil
+	uw.db = ""
+	uw.tsMultiplier = 0
+	uw.reqBuf = uw.reqBuf[:0]
+}
+
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	uw.rows.Unmarshal(bytesutil.ToUnsafeString(uw.reqBuf))
+	rows := uw.rows.Rows
+	rowsRead.Add(len(rows))
+
+	// Adjust timestamps according to uw.tsMultiplier
+	currentTs := time.Now().UnixNano() / 1e6
+	tsMultiplier := uw.tsMultiplier
+	if tsMultiplier >= 1 {
+		for i := range rows {
+			row := &rows[i]
+			if row.Timestamp == 0 {
+				row.Timestamp = currentTs
+			} else {
+				row.Timestamp /= tsMultiplier
+			}
+		}
+	} else if tsMultiplier < 0 {
+		tsMultiplier = -tsMultiplier
+		currentTs -= currentTs % tsMultiplier
+		for i := range rows {
+			row := &rows[i]
+			if row.Timestamp == 0 {
+				row.Timestamp = currentTs
+			} else {
+				row.Timestamp *= tsMultiplier
+			}
+		}
+	}
+
+	// Trim timestamps if required.
+	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1 {
+		for i := range rows {
+			row := &rows[i]
+			row.Timestamp -= row.Timestamp % tsTrim
+		}
+	}
+
+	if err := uw.callback(uw.db, rows); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
+func getUnmarshalWork() *unmarshalWork {
+	v := unmarshalWorkPool.Get()
+	if v == nil {
+		return &unmarshalWork{}
+	}
+	return v.(*unmarshalWork)
+}
+
+func putUnmarshalWork(uw *unmarshalWork) {
+	uw.reset()
+	unmarshalWorkPool.Put(uw)
+}
+
+var unmarshalWorkPool sync.Pool

lib/protoparser/native/streamparser.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net/http"
-	"runtime"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
@@ -45,46 +44,18 @@ func ParseStream(req *http.Request, callback func(block *Block) error) error {
 	tr.MinTimestamp = encoding.UnmarshalInt64(trBuf)
 	tr.MaxTimestamp = encoding.UnmarshalInt64(trBuf[8:])
 
-	// Start GOMAXPROC workers in order to process ingested data in parallel.
-	gomaxprocs := runtime.GOMAXPROCS(-1)
-	workCh := make(chan *unmarshalWork, 8*gomaxprocs)
-	var wg sync.WaitGroup
-	defer func() {
-		close(workCh)
-		wg.Wait()
-	}()
-	wg.Add(gomaxprocs)
-	for i := 0; i < gomaxprocs; i++ {
-		go func() {
-			defer wg.Done()
-			var tmpBlock storage.Block
-			for uw := range workCh {
-				if err := uw.unmarshal(&tmpBlock, tr); err != nil {
-					parseErrors.Inc()
-					logger.Errorf("error when unmarshaling native block: %s", err)
-					putUnmarshalWork(uw)
-					continue
-				}
-				if err := callback(&uw.block); err != nil {
-					processErrors.Inc()
-					logger.Errorf("error when processing native block: %s", err)
-					putUnmarshalWork(uw)
-					continue
-				}
-				putUnmarshalWork(uw)
-			}
-		}()
-	}
-
 	// Read native blocks and feed workers with work.
 	sizeBuf := make([]byte, 4)
 	for {
 		uw := getUnmarshalWork()
+		uw.tr = tr
+		uw.callback = callback
 
 		// Read uw.metricNameBuf
 		if _, err := io.ReadFull(br, sizeBuf); err != nil {
 			if err == io.EOF {
 				// End of stream
+				putUnmarshalWork(uw)
 				return nil
 			}
 			readErrors.Inc()
@@ -122,8 +93,7 @@ func ParseStream(req *http.Request, callback func(block *Block) error) error {
 		readCalls.Inc()
 		blocksRead.Inc()
 
-		// Feed workers with work.
-		workCh <- uw
+		common.ScheduleUnmarshalWork(uw)
 	}
 }
 
@@ -152,22 +122,43 @@ var (
 
 type unmarshalWork struct {
 	tr            storage.TimeRange
+	callback      func(block *Block) error
 	metricNameBuf []byte
 	blockBuf      []byte
 	block         Block
 }
 
 func (uw *unmarshalWork) reset() {
+	uw.callback = nil
 	uw.metricNameBuf = uw.metricNameBuf[:0]
 	uw.blockBuf = uw.blockBuf[:0]
 	uw.block.reset()
 }
 
-func (uw *unmarshalWork) unmarshal(tmpBlock *storage.Block, tr storage.TimeRange) error {
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	if err := uw.unmarshal(); err != nil {
+		parseErrors.Inc()
+		logger.Errorf("error when unmarshaling native block: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	if err := uw.callback(&uw.block); err != nil {
+		processErrors.Inc()
+		logger.Errorf("error when processing native block: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
+func (uw *unmarshalWork) unmarshal() error {
 	block := &uw.block
 	if err := block.MetricName.Unmarshal(uw.metricNameBuf); err != nil {
 		return fmt.Errorf("cannot unmarshal metricName from %d bytes: %w", len(uw.metricNameBuf), err)
 	}
+	tmpBlock := blockPool.Get().(*storage.Block)
+	defer blockPool.Put(tmpBlock)
 	tail, err := tmpBlock.UnmarshalPortable(uw.blockBuf)
 	if err != nil {
 		return fmt.Errorf("cannot unmarshal native block from %d bytes: %w", len(uw.blockBuf), err)
@@ -175,11 +166,17 @@ func (uw *unmarshalWork) unmarshal(tmpBlock *storage.Block, tr storage.TimeRange
 	if len(tail) > 0 {
 		return fmt.Errorf("unexpected non-empty tail left after unmarshaling native block from %d bytes; len(tail)=%d bytes", len(uw.blockBuf), len(tail))
 	}
-	block.Timestamps, block.Values = tmpBlock.AppendRowsWithTimeRangeFilter(block.Timestamps[:0], block.Values[:0], tr)
+	block.Timestamps, block.Values = tmpBlock.AppendRowsWithTimeRangeFilter(block.Timestamps[:0], block.Values[:0], uw.tr)
 	rowsRead.Add(len(block.Timestamps))
 	return nil
 }
 
+var blockPool = &sync.Pool{
+	New: func() interface{} {
+		return &storage.Block{}
+	},
+}
+
 func getUnmarshalWork() *unmarshalWork {
 	v := unmarshalWorkPool.Get()
 	if v == nil {

lib/protoparser/opentsdb/streamparser.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -29,9 +30,10 @@ func ParseStream(r io.Reader, callback func(rows []Row) error) error {
 	ctx := getStreamContext(r)
 	defer putStreamContext(ctx)
 	for ctx.Read() {
-		if err := callback(ctx.Rows.Rows); err != nil {
-			return err
-		}
+		uw := getUnmarshalWork()
+		uw.callback = callback
+		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
 }
@@ -49,38 +51,10 @@ func (ctx *streamContext) Read() bool {
 		}
 		return false
 	}
-	ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf))
-	rowsRead.Add(len(ctx.Rows.Rows))
-
-	rows := ctx.Rows.Rows
-
-	// Fill in missing timestamps
-	currentTimestamp := int64(fasttime.UnixTimestamp())
-	for i := range rows {
-		r := &rows[i]
-		if r.Timestamp == 0 {
-			r.Timestamp = currentTimestamp
-		}
-	}
-
-	// Convert timestamps from seconds to milliseconds
-	for i := range rows {
-		rows[i].Timestamp *= 1e3
-	}
-
-	// Trim timestamps if required.
-	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1000 {
-		for i := range rows {
-			row := &rows[i]
-			row.Timestamp -= row.Timestamp % tsTrim
-		}
-	}
-
 	return true
 }
 
 type streamContext struct {
-	Rows    Rows
 	br      *bufio.Reader
 	reqBuf  []byte
 	tailBuf []byte
@@ -95,7 +69,6 @@ func (ctx *streamContext) Error() error {
 }
 
 func (ctx *streamContext) reset() {
-	ctx.Rows.Reset()
 	ctx.br.Reset(nil)
 	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
@@ -136,3 +109,66 @@ func putStreamContext(ctx *streamContext) {
 
 var streamContextPool sync.Pool
 var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))
+
+type unmarshalWork struct {
+	rows     Rows
+	callback func(rows []Row) error
+	reqBuf   []byte
+}
+
+func (uw *unmarshalWork) reset() {
+	uw.rows.Reset()
+	uw.callback = nil
+	uw.reqBuf = uw.reqBuf[:0]
+}
+
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	uw.rows.Unmarshal(bytesutil.ToUnsafeString(uw.reqBuf))
+	rows := uw.rows.Rows
+	rowsRead.Add(len(rows))
+
+	// Fill in missing timestamps
+	currentTimestamp := int64(fasttime.UnixTimestamp())
+	for i := range rows {
+		r := &rows[i]
+		if r.Timestamp == 0 {
+			r.Timestamp = currentTimestamp
+		}
+	}
+
+	// Convert timestamps from seconds to milliseconds
+	for i := range rows {
+		rows[i].Timestamp *= 1e3
+	}
+
+	// Trim timestamps if required.
+	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1000 {
+		for i := range rows {
+			row := &rows[i]
+			row.Timestamp -= row.Timestamp % tsTrim
+		}
+	}
+
+	if err := uw.callback(rows); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
+func getUnmarshalWork() *unmarshalWork {
+	v := unmarshalWorkPool.Get()
+	if v == nil {
+		return &unmarshalWork{}
+	}
+	return v.(*unmarshalWork)
+}
+
+func putUnmarshalWork(uw *unmarshalWork) {
+	uw.reset()
+	unmarshalWorkPool.Put(uw)
+}
+
+var unmarshalWorkPool sync.Pool

lib/protoparser/opentsdbhttp/parser_pool.go

@@ -4,17 +4,17 @@ import (
 	"github.com/valyala/fastjson"
 )
 
-// GetParser returns JSON parser.
+// getJSONParser returns JSON parser.
 //
-// The parser must be returned to the pool via PutParser when no longer needed.
-func GetParser() *fastjson.Parser {
+// The parser must be returned to the pool via putJSONParser when no longer needed.
+func getJSONParser() *fastjson.Parser {
 	return parserPool.Get()
 }
 
-// PutParser returns p to the pool.
+// putJSONParser returns p to the pool.
 //
 // p cannot be used after returning to the pool.
-func PutParser(p *fastjson.Parser) {
+func putJSONParser(p *fastjson.Parser) {
 	parserPool.Put(p)
 }
 

lib/protoparser/opentsdbhttp/parser_test.go

@@ -9,8 +9,8 @@ func TestRowsUnmarshalFailure(t *testing.T) {
 	f := func(s string) {
 		t.Helper()
 		var rows Rows
-		p := GetParser()
-		defer PutParser(p)
+		p := getJSONParser()
+		defer putJSONParser(p)
 		v, err := p.Parse(s)
 		if err != nil {
 			// Expected JSON parser error
@@ -84,8 +84,8 @@ func TestRowsUnmarshalSuccess(t *testing.T) {
 		t.Helper()
 		var rows Rows
 
-		p := GetParser()
-		defer PutParser(p)
+		p := getJSONParser()
+		defer putJSONParser(p)
 		v, err := p.Parse(s)
 		if err != nil {
 			t.Fatalf("cannot parse json %s: %s", s, err)

lib/protoparser/opentsdbhttp/streamparser.go

@@ -13,6 +13,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -56,59 +57,21 @@ func ParseStream(req *http.Request, callback func(rows []Row) error) error {
 		return fmt.Errorf("too big HTTP OpenTSDB request; mustn't exceed `-opentsdbhttp.maxInsertRequestSize=%d` bytes", maxInsertRequestSize.N)
 	}
 
-	// Unmarshal the request to ctx.Rows
-	p := GetParser()
-	defer PutParser(p)
-	v, err := p.ParseBytes(ctx.reqBuf.B)
-	if err != nil {
-		unmarshalErrors.Inc()
-		return fmt.Errorf("cannot parse HTTP OpenTSDB json: %w", err)
-	}
-	ctx.Rows.Unmarshal(v)
-	rowsRead.Add(len(ctx.Rows.Rows))
-
-	rows := ctx.Rows.Rows
-
-	// Fill in missing timestamps
-	currentTimestamp := int64(fasttime.UnixTimestamp())
-	for i := range rows {
-		r := &rows[i]
-		if r.Timestamp == 0 {
-			r.Timestamp = currentTimestamp
-		}
-	}
-
-	// Convert timestamps in seconds to milliseconds if needed.
-	// See http://opentsdb.net/docs/javadoc/net/opentsdb/core/Const.html#SECOND_MASK
-	for i := range rows {
-		r := &rows[i]
-		if r.Timestamp&secondMask == 0 {
-			r.Timestamp *= 1e3
-		}
-	}
-
-	// Trim timestamps if required.
-	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1 {
-		for i := range rows {
-			row := &rows[i]
-			row.Timestamp -= row.Timestamp % tsTrim
-		}
-	}
-
-	// Insert ctx.Rows to db.
-	return callback(rows)
+	uw := getUnmarshalWork()
+	uw.callback = callback
+	uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf.B...)
+	common.ScheduleUnmarshalWork(uw)
+	return nil
 }
 
 const secondMask int64 = 0x7FFFFFFF00000000
 
 type streamContext struct {
-	Rows   Rows
 	br     *bufio.Reader
 	reqBuf bytesutil.ByteBuffer
 }
 
 func (ctx *streamContext) reset() {
-	ctx.Rows.Reset()
 	ctx.br.Reset(nil)
 	ctx.reqBuf.Reset()
 }
@@ -148,3 +111,78 @@ func putStreamContext(ctx *streamContext) {
 
 var streamContextPool sync.Pool
 var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))
+
+type unmarshalWork struct {
+	rows     Rows
+	callback func(rows []Row) error
+	reqBuf   []byte
+}
+
+func (uw *unmarshalWork) reset() {
+	uw.rows.Reset()
+	uw.callback = nil
+	uw.reqBuf = uw.reqBuf[:0]
+}
+
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	p := getJSONParser()
+	defer putJSONParser(p)
+	v, err := p.ParseBytes(uw.reqBuf)
+	if err != nil {
+		unmarshalErrors.Inc()
+		logger.Errorf("cannot parse HTTP OpenTSDB json: %s", err)
+		return
+	}
+	uw.rows.Unmarshal(v)
+	rows := uw.rows.Rows
+	rowsRead.Add(len(rows))
+
+	// Fill in missing timestamps
+	currentTimestamp := int64(fasttime.UnixTimestamp())
+	for i := range rows {
+		r := &rows[i]
+		if r.Timestamp == 0 {
+			r.Timestamp = currentTimestamp
+		}
+	}
+
+	// Convert timestamps in seconds to milliseconds if needed.
+	// See http://opentsdb.net/docs/javadoc/net/opentsdb/core/Const.html#SECOND_MASK
+	for i := range rows {
+		r := &rows[i]
+		if r.Timestamp&secondMask == 0 {
+			r.Timestamp *= 1e3
+		}
+	}
+
+	// Trim timestamps if required.
+	if tsTrim := trimTimestamp.Milliseconds(); tsTrim > 1 {
+		for i := range rows {
+			row := &rows[i]
+			row.Timestamp -= row.Timestamp % tsTrim
+		}
+	}
+
+	if err := uw.callback(rows); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
+func getUnmarshalWork() *unmarshalWork {
+	v := unmarshalWorkPool.Get()
+	if v == nil {
+		return &unmarshalWork{}
+	}
+	return v.(*unmarshalWork)
+}
+
+func putUnmarshalWork(uw *unmarshalWork) {
+	uw.reset()
+	unmarshalWorkPool.Put(uw)
+}
+
+var unmarshalWorkPool sync.Pool

lib/protoparser/prometheus/streamparser.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -29,15 +30,17 @@ func ParseStream(r io.Reader, defaultTimestamp int64, isGzipped bool, callback f
 	}
 	ctx := getStreamContext(r)
 	defer putStreamContext(ctx)
-	for ctx.Read(defaultTimestamp) {
-		if err := callback(ctx.Rows.Rows); err != nil {
-			return err
-		}
+	for ctx.Read() {
+		uw := getUnmarshalWork()
+		uw.callback = callback
+		uw.defaultTimestamp = defaultTimestamp
+		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
+		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
 }
 
-func (ctx *streamContext) Read(defaultTimestamp int64) bool {
+func (ctx *streamContext) Read() bool {
 	readCalls.Inc()
 	if ctx.err != nil {
 		return false
@@ -50,26 +53,10 @@ func (ctx *streamContext) Read(defaultTimestamp int64) bool {
 		}
 		return false
 	}
-	ctx.Rows.Unmarshal(bytesutil.ToUnsafeString(ctx.reqBuf))
-	rowsRead.Add(len(ctx.Rows.Rows))
-
-	rows := ctx.Rows.Rows
-
-	// Fill missing timestamps with the current timestamp.
-	if defaultTimestamp <= 0 {
-		defaultTimestamp = int64(time.Now().UnixNano() / 1e6)
-	}
-	for i := range rows {
-		r := &rows[i]
-		if r.Timestamp == 0 {
-			r.Timestamp = defaultTimestamp
-		}
-	}
 	return true
 }
 
 type streamContext struct {
-	Rows    Rows
 	br      *bufio.Reader
 	reqBuf  []byte
 	tailBuf []byte
@@ -84,7 +71,6 @@ func (ctx *streamContext) Error() error {
 }
 
 func (ctx *streamContext) reset() {
-	ctx.Rows.Reset()
 	ctx.br.Reset(nil)
 	ctx.reqBuf = ctx.reqBuf[:0]
 	ctx.tailBuf = ctx.tailBuf[:0]
@@ -125,3 +111,58 @@ func putStreamContext(ctx *streamContext) {
 
 var streamContextPool sync.Pool
 var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))
+
+type unmarshalWork struct {
+	rows             Rows
+	callback         func(rows []Row) error
+	defaultTimestamp int64
+	reqBuf           []byte
+}
+
+func (uw *unmarshalWork) reset() {
+	uw.rows.Reset()
+	uw.callback = nil
+	uw.defaultTimestamp = 0
+	uw.reqBuf = uw.reqBuf[:0]
+}
+
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	uw.rows.Unmarshal(bytesutil.ToUnsafeString(uw.reqBuf))
+	rows := uw.rows.Rows
+	rowsRead.Add(len(rows))
+
+	// Fill missing timestamps with the current timestamp.
+	defaultTimestamp := uw.defaultTimestamp
+	if defaultTimestamp <= 0 {
+		defaultTimestamp = int64(time.Now().UnixNano() / 1e6)
+	}
+	for i := range rows {
+		r := &rows[i]
+		if r.Timestamp == 0 {
+			r.Timestamp = defaultTimestamp
+		}
+	}
+
+	if err := uw.callback(rows); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
+func getUnmarshalWork() *unmarshalWork {
+	v := unmarshalWorkPool.Get()
+	if v == nil {
+		return &unmarshalWork{}
+	}
+	return v.(*unmarshalWork)
+}
+
+func putUnmarshalWork(uw *unmarshalWork) {
+	uw.reset()
+	unmarshalWorkPool.Put(uw)
+}
+
+var unmarshalWorkPool sync.Pool

lib/protoparser/promremotewrite/streamparser.go

@@ -10,7 +10,9 @@ import (
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompb"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	"github.com/VictoriaMetrics/metrics"
 	"github.com/golang/snappy"
 )
@@ -19,49 +21,42 @@ var maxInsertRequestSize = flagutil.NewBytes("maxInsertRequestSize", 32*1024*102
 
 // ParseStream parses Prometheus remote_write message req and calls callback for the parsed timeseries.
 //
-// callback shouldn't hold timeseries after returning.
-func ParseStream(req *http.Request, callback func(timeseries []prompb.TimeSeries) error) error {
+// callback shouldn't hold tss after returning.
+func ParseStream(req *http.Request, callback func(tss []prompb.TimeSeries) error) error {
 	ctx := getPushCtx(req.Body)
 	defer putPushCtx(ctx)
 	if err := ctx.Read(); err != nil {
 		return err
 	}
-	return callback(ctx.wr.Timeseries)
+	uw := getUnmarshalWork()
+	uw.callback = callback
+	uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf.B...)
+	common.ScheduleUnmarshalWork(uw)
+	return nil
 }
 
 type pushCtx struct {
-	wr     prompb.WriteRequest
 	br     *bufio.Reader
-	reqBuf []byte
+	reqBuf bytesutil.ByteBuffer
 }
 
 func (ctx *pushCtx) reset() {
-	ctx.wr.Reset()
 	ctx.br.Reset(nil)
-	ctx.reqBuf = ctx.reqBuf[:0]
+	ctx.reqBuf.Reset()
 }
 
 func (ctx *pushCtx) Read() error {
 	readCalls.Inc()
-	var err error
-
-	ctx.reqBuf, err = readSnappy(ctx.reqBuf[:0], ctx.br)
+	lr := io.LimitReader(ctx.br, int64(maxInsertRequestSize.N)+1)
+	reqLen, err := ctx.reqBuf.ReadFrom(lr)
 	if err != nil {
 		readErrors.Inc()
-		return fmt.Errorf("cannot read prompb.WriteRequest: %w", err)
+		return fmt.Errorf("cannot read compressed request: %w", err)
 	}
-	if err = ctx.wr.Unmarshal(ctx.reqBuf); err != nil {
-		unmarshalErrors.Inc()
-		return fmt.Errorf("cannot unmarshal prompb.WriteRequest with size %d bytes: %w", len(ctx.reqBuf), err)
+	if reqLen > int64(maxInsertRequestSize.N) {
+		readErrors.Inc()
+		return fmt.Errorf("too big packed request; mustn't exceed `-maxInsertRequestSize=%d` bytes", maxInsertRequestSize.N)
 	}
-
-	rows := 0
-	tss := ctx.wr.Timeseries
-	for i := range tss {
-		rows += len(tss[i].Samples)
-	}
-	rowsRead.Add(rows)
-
 	return nil
 }
 
@@ -101,34 +96,66 @@ func putPushCtx(ctx *pushCtx) {
 var pushCtxPool sync.Pool
 var pushCtxPoolCh = make(chan *pushCtx, runtime.GOMAXPROCS(-1))
 
-func readSnappy(dst []byte, r io.Reader) ([]byte, error) {
-	lr := io.LimitReader(r, int64(maxInsertRequestSize.N)+1)
+type unmarshalWork struct {
+	wr       prompb.WriteRequest
+	callback func(tss []prompb.TimeSeries) error
+	reqBuf   []byte
+}
+
+func (uw *unmarshalWork) reset() {
+	uw.wr.Reset()
+	uw.callback = nil
+	uw.reqBuf = uw.reqBuf[:0]
+}
+
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
 	bb := bodyBufferPool.Get()
-	reqLen, err := bb.ReadFrom(lr)
+	defer bodyBufferPool.Put(bb)
+	var err error
+	bb.B, err = snappy.Decode(bb.B[:cap(bb.B)], uw.reqBuf)
 	if err != nil {
-		bodyBufferPool.Put(bb)
-		return dst, fmt.Errorf("cannot read compressed request: %w", err)
+		logger.Errorf("cannot decompress request with length %d: %s", len(uw.reqBuf), err)
+		return
 	}
-	if reqLen > int64(maxInsertRequestSize.N) {
-		return dst, fmt.Errorf("too big packed request; mustn't exceed `-maxInsertRequestSize=%d` bytes", maxInsertRequestSize.N)
+	if len(bb.B) > maxInsertRequestSize.N {
+		logger.Errorf("too big unpacked request; mustn't exceed `-maxInsertRequestSize=%d` bytes; got %d bytes", maxInsertRequestSize.N, len(bb.B))
+		return
+	}
+	if err := uw.wr.Unmarshal(bb.B); err != nil {
+		unmarshalErrors.Inc()
+		logger.Errorf("cannot unmarshal prompb.WriteRequest with size %d bytes: %s", len(bb.B), err)
+		return
 	}
 
-	buf := dst[len(dst):cap(dst)]
-	buf, err = snappy.Decode(buf, bb.B)
-	bodyBufferPool.Put(bb)
-	if err != nil {
-		err = fmt.Errorf("cannot decompress request with length %d: %w", reqLen, err)
-		return dst, err
+	rows := 0
+	tss := uw.wr.Timeseries
+	for i := range tss {
+		rows += len(tss[i].Samples)
 	}
-	if len(buf) > maxInsertRequestSize.N {
-		return dst, fmt.Errorf("too big unpacked request; mustn't exceed `-maxInsertRequestSize=%d` bytes; got %d bytes", maxInsertRequestSize.N, len(buf))
+	rowsRead.Add(rows)
+
+	if err := uw.callback(tss); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
 	}
-	if len(buf) > 0 && len(dst) < cap(dst) && &buf[0] == &dst[len(dst):cap(dst)][0] {
-		dst = dst[:len(dst)+len(buf)]
-	} else {
-		dst = append(dst, buf...)
-	}
-	return dst, nil
+	putUnmarshalWork(uw)
 }
 
 var bodyBufferPool bytesutil.ByteBufferPool
+
+func getUnmarshalWork() *unmarshalWork {
+	v := unmarshalWorkPool.Get()
+	if v == nil {
+		return &unmarshalWork{}
+	}
+	return v.(*unmarshalWork)
+}
+
+func putUnmarshalWork(uw *unmarshalWork) {
+	uw.reset()
+	unmarshalWorkPool.Put(uw)
+}
+
+var unmarshalWorkPool sync.Pool

lib/protoparser/vmimport/streamparser.go

@@ -34,42 +34,13 @@ func ParseStream(req *http.Request, callback func(rows []Row) error) error {
 		defer common.PutGzipReader(zr)
 		r = zr
 	}
-
-	// Start gomaxprocs workers for processing the parsed data in parallel.
-	gomaxprocs := runtime.GOMAXPROCS(-1)
-	workCh := make(chan *unmarshalWork, 8*gomaxprocs)
-	var wg sync.WaitGroup
-	defer func() {
-		close(workCh)
-		wg.Wait()
-	}()
-	wg.Add(gomaxprocs)
-	for i := 0; i < gomaxprocs; i++ {
-		go func() {
-			defer wg.Done()
-			for uw := range workCh {
-				uw.rows.Unmarshal(bytesutil.ToUnsafeString(uw.reqBuf))
-				rows := uw.rows.Rows
-				for i := range rows {
-					row := &rows[i]
-					rowsRead.Add(len(row.Timestamps))
-				}
-				if err := callback(rows); err != nil {
-					logger.Errorf("error when processing imported data: %s", err)
-					putUnmarshalWork(uw)
-					continue
-				}
-				putUnmarshalWork(uw)
-			}
-		}()
-	}
-
 	ctx := getStreamContext(r)
 	defer putStreamContext(ctx)
 	for ctx.Read() {
 		uw := getUnmarshalWork()
+		uw.callback = callback
 		uw.reqBuf = append(uw.reqBuf[:0], ctx.reqBuf...)
-		workCh <- uw
+		common.ScheduleUnmarshalWork(uw)
 	}
 	return ctx.Error()
 }
@@ -147,15 +118,33 @@ var streamContextPool sync.Pool
 var streamContextPoolCh = make(chan *streamContext, runtime.GOMAXPROCS(-1))
 
 type unmarshalWork struct {
-	rows   Rows
-	reqBuf []byte
+	rows     Rows
+	callback func(rows []Row) error
+	reqBuf   []byte
 }
 
 func (uw *unmarshalWork) reset() {
 	uw.rows.Reset()
+	uw.callback = nil
 	uw.reqBuf = uw.reqBuf[:0]
 }
 
+// Unmarshal implements common.UnmarshalWork
+func (uw *unmarshalWork) Unmarshal() {
+	uw.rows.Unmarshal(bytesutil.ToUnsafeString(uw.reqBuf))
+	rows := uw.rows.Rows
+	for i := range rows {
+		row := &rows[i]
+		rowsRead.Add(len(row.Timestamps))
+	}
+	if err := uw.callback(rows); err != nil {
+		logger.Errorf("error when processing imported data: %s", err)
+		putUnmarshalWork(uw)
+		return
+	}
+	putUnmarshalWork(uw)
+}
+
 func getUnmarshalWork() *unmarshalWork {
 	v := unmarshalWorkPool.Get()
 	if v == nil {