VictoriaMetrics/app/vmagent/remotewrite/pendingseries.go
Aliaksandr Valialkin 3449d563bd
all: add up to 10% random jitter to the interval between periodic tasks performed by various components
This should smooth CPU and RAM usage spikes related to these periodic tasks,
by reducing the probability that multiple concurrent periodic tasks are performed at the same time.
2024-01-22 18:40:32 +02:00

300 lines
9 KiB
Go

package remotewrite
import (
"flag"
"sync"
"sync/atomic"
"time"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/decimal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding/zstd"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/persistentqueue"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/timeutil"
"github.com/VictoriaMetrics/metrics"
"github.com/golang/snappy"
)
var (
flushInterval = flag.Duration("remoteWrite.flushInterval", time.Second, "Interval for flushing the data to remote storage. "+
"This option takes effect only when less than 10K data points per second are pushed to -remoteWrite.url")
maxUnpackedBlockSize = flagutil.NewBytes("remoteWrite.maxBlockSize", 8*1024*1024, "The maximum block size to send to remote storage. Bigger blocks may improve performance at the cost of the increased memory usage. See also -remoteWrite.maxRowsPerBlock")
maxRowsPerBlock = flag.Int("remoteWrite.maxRowsPerBlock", 10000, "The maximum number of samples to send in each block to remote storage. Higher number may improve performance at the cost of the increased memory usage. See also -remoteWrite.maxBlockSize")
vmProtoCompressLevel = flag.Int("remoteWrite.vmProtoCompressLevel", 0, "The compression level for VictoriaMetrics remote write protocol. "+
"Higher values reduce network traffic at the cost of higher CPU usage. Negative values reduce CPU usage at the cost of increased network traffic. "+
"See https://docs.victoriametrics.com/vmagent.html#victoriametrics-remote-write-protocol")
)
type pendingSeries struct {
mu sync.Mutex
wr writeRequest
stopCh chan struct{}
periodicFlusherWG sync.WaitGroup
}
func newPendingSeries(fq *persistentqueue.FastQueue, isVMRemoteWrite bool, significantFigures, roundDigits int) *pendingSeries {
var ps pendingSeries
ps.wr.fq = fq
ps.wr.isVMRemoteWrite = isVMRemoteWrite
ps.wr.significantFigures = significantFigures
ps.wr.roundDigits = roundDigits
ps.stopCh = make(chan struct{})
ps.periodicFlusherWG.Add(1)
go func() {
defer ps.periodicFlusherWG.Done()
ps.periodicFlusher()
}()
return &ps
}
func (ps *pendingSeries) MustStop() {
close(ps.stopCh)
ps.periodicFlusherWG.Wait()
}
func (ps *pendingSeries) TryPush(tss []prompbmarshal.TimeSeries) bool {
ps.mu.Lock()
ok := ps.wr.tryPush(tss)
ps.mu.Unlock()
return ok
}
func (ps *pendingSeries) periodicFlusher() {
flushSeconds := int64(flushInterval.Seconds())
if flushSeconds <= 0 {
flushSeconds = 1
}
d := timeutil.AddJitterToDuration(*flushInterval)
ticker := time.NewTicker(d)
defer ticker.Stop()
for {
select {
case <-ps.stopCh:
ps.mu.Lock()
ps.wr.mustFlushOnStop()
ps.mu.Unlock()
return
case <-ticker.C:
if fasttime.UnixTimestamp()-atomic.LoadUint64(&ps.wr.lastFlushTime) < uint64(flushSeconds) {
continue
}
}
ps.mu.Lock()
_ = ps.wr.tryFlush()
ps.mu.Unlock()
}
}
type writeRequest struct {
// Move lastFlushTime to the top of the struct in order to guarantee atomic access on 32-bit architectures.
lastFlushTime uint64
// The queue to send blocks to.
fq *persistentqueue.FastQueue
// Whether to encode the write request with VictoriaMetrics remote write protocol.
isVMRemoteWrite bool
// How many significant figures must be left before sending the writeRequest to fq.
significantFigures int
// How many decimal digits after point must be left before sending the writeRequest to fq.
roundDigits int
wr prompbmarshal.WriteRequest
tss []prompbmarshal.TimeSeries
labels []prompbmarshal.Label
samples []prompbmarshal.Sample
buf []byte
}
func (wr *writeRequest) reset() {
// Do not reset lastFlushTime, fq, isVMRemoteWrite, significantFigures and roundDigits, since they are re-used.
wr.wr.Timeseries = nil
for i := range wr.tss {
ts := &wr.tss[i]
ts.Labels = nil
ts.Samples = nil
}
wr.tss = wr.tss[:0]
promrelabel.CleanLabels(wr.labels)
wr.labels = wr.labels[:0]
wr.samples = wr.samples[:0]
wr.buf = wr.buf[:0]
}
// mustFlushOnStop force pushes wr data into wr.fq
//
// This is needed in order to properly save in-memory data to persistent queue on graceful shutdown.
func (wr *writeRequest) mustFlushOnStop() {
wr.wr.Timeseries = wr.tss
if !tryPushWriteRequest(&wr.wr, wr.mustWriteBlock, wr.isVMRemoteWrite) {
logger.Panicf("BUG: final flush must always return true")
}
wr.reset()
}
func (wr *writeRequest) mustWriteBlock(block []byte) bool {
wr.fq.MustWriteBlockIgnoreDisabledPQ(block)
return true
}
func (wr *writeRequest) tryFlush() bool {
wr.wr.Timeseries = wr.tss
atomic.StoreUint64(&wr.lastFlushTime, fasttime.UnixTimestamp())
if !tryPushWriteRequest(&wr.wr, wr.fq.TryWriteBlock, wr.isVMRemoteWrite) {
return false
}
wr.reset()
return true
}
func adjustSampleValues(samples []prompbmarshal.Sample, significantFigures, roundDigits int) {
if n := significantFigures; n > 0 {
for i := range samples {
s := &samples[i]
s.Value = decimal.RoundToSignificantFigures(s.Value, n)
}
}
if n := roundDigits; n < 100 {
for i := range samples {
s := &samples[i]
s.Value = decimal.RoundToDecimalDigits(s.Value, n)
}
}
}
func (wr *writeRequest) tryPush(src []prompbmarshal.TimeSeries) bool {
tssDst := wr.tss
maxSamplesPerBlock := *maxRowsPerBlock
// Allow up to 10x of labels per each block on average.
maxLabelsPerBlock := 10 * maxSamplesPerBlock
for i := range src {
if len(wr.samples) >= maxSamplesPerBlock || len(wr.labels) >= maxLabelsPerBlock {
wr.tss = tssDst
if !wr.tryFlush() {
return false
}
tssDst = wr.tss
}
tsSrc := &src[i]
adjustSampleValues(tsSrc.Samples, wr.significantFigures, wr.roundDigits)
tssDst = append(tssDst, prompbmarshal.TimeSeries{})
wr.copyTimeSeries(&tssDst[len(tssDst)-1], tsSrc)
}
wr.tss = tssDst
return true
}
func (wr *writeRequest) copyTimeSeries(dst, src *prompbmarshal.TimeSeries) {
labelsDst := wr.labels
labelsLen := len(wr.labels)
samplesDst := wr.samples
buf := wr.buf
for i := range src.Labels {
labelsDst = append(labelsDst, prompbmarshal.Label{})
dstLabel := &labelsDst[len(labelsDst)-1]
srcLabel := &src.Labels[i]
buf = append(buf, srcLabel.Name...)
dstLabel.Name = bytesutil.ToUnsafeString(buf[len(buf)-len(srcLabel.Name):])
buf = append(buf, srcLabel.Value...)
dstLabel.Value = bytesutil.ToUnsafeString(buf[len(buf)-len(srcLabel.Value):])
}
dst.Labels = labelsDst[labelsLen:]
samplesDst = append(samplesDst, src.Samples...)
dst.Samples = samplesDst[len(samplesDst)-len(src.Samples):]
wr.samples = samplesDst
wr.labels = labelsDst
wr.buf = buf
}
func tryPushWriteRequest(wr *prompbmarshal.WriteRequest, tryPushBlock func(block []byte) bool, isVMRemoteWrite bool) bool {
if len(wr.Timeseries) == 0 {
// Nothing to push
return true
}
bb := writeRequestBufPool.Get()
bb.B = wr.MarshalProtobuf(bb.B[:0])
if len(bb.B) <= maxUnpackedBlockSize.IntN() {
zb := snappyBufPool.Get()
if isVMRemoteWrite {
zb.B = zstd.CompressLevel(zb.B[:0], bb.B, *vmProtoCompressLevel)
} else {
zb.B = snappy.Encode(zb.B[:cap(zb.B)], bb.B)
}
writeRequestBufPool.Put(bb)
if len(zb.B) <= persistentqueue.MaxBlockSize {
if !tryPushBlock(zb.B) {
return false
}
blockSizeRows.Update(float64(len(wr.Timeseries)))
blockSizeBytes.Update(float64(len(zb.B)))
snappyBufPool.Put(zb)
return true
}
snappyBufPool.Put(zb)
} else {
writeRequestBufPool.Put(bb)
}
// Too big block. Recursively split it into smaller parts if possible.
if len(wr.Timeseries) == 1 {
// A single time series left. Recursively split its samples into smaller parts if possible.
samples := wr.Timeseries[0].Samples
if len(samples) == 1 {
logger.Warnf("dropping a sample for metric with too long labels exceeding -remoteWrite.maxBlockSize=%d bytes", maxUnpackedBlockSize.N)
return true
}
n := len(samples) / 2
wr.Timeseries[0].Samples = samples[:n]
if !tryPushWriteRequest(wr, tryPushBlock, isVMRemoteWrite) {
wr.Timeseries[0].Samples = samples
return false
}
wr.Timeseries[0].Samples = samples[n:]
if !tryPushWriteRequest(wr, tryPushBlock, isVMRemoteWrite) {
wr.Timeseries[0].Samples = samples
return false
}
wr.Timeseries[0].Samples = samples
return true
}
timeseries := wr.Timeseries
n := len(timeseries) / 2
wr.Timeseries = timeseries[:n]
if !tryPushWriteRequest(wr, tryPushBlock, isVMRemoteWrite) {
wr.Timeseries = timeseries
return false
}
wr.Timeseries = timeseries[n:]
if !tryPushWriteRequest(wr, tryPushBlock, isVMRemoteWrite) {
wr.Timeseries = timeseries
return false
}
wr.Timeseries = timeseries
return true
}
var (
blockSizeBytes = metrics.NewHistogram(`vmagent_remotewrite_block_size_bytes`)
blockSizeRows = metrics.NewHistogram(`vmagent_remotewrite_block_size_rows`)
)
var writeRequestBufPool bytesutil.ByteBufferPool
var snappyBufPool bytesutil.ByteBufferPool