VictoriaMetrics/lib/promscrape/scrapework.go

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package promscrape
import (
"flag"
"fmt"
"math"
"math/bits"
"strconv"
"strings"
"sync"
"time"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bloomfilter"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/decimal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/leveledbytebufferpool"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/promauth"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
parser "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/proxy"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/timerpool"
"github.com/VictoriaMetrics/metrics"
xxhash "github.com/cespare/xxhash/v2"
)
var (
suppressScrapeErrors = flag.Bool("promscrape.suppressScrapeErrors", false, "Whether to suppress scrape errors logging. "+
"The last error for each target is always available at '/targets' page even if scrape errors logging is suppressed")
noStaleMarkers = flag.Bool("promscrape.noStaleMarkers", false, "Whether to disable sending Prometheus stale markers for metrics when scrape target disappears. This option may reduce memory usage if stale markers aren't needed for your setup. See also https://docs.victoriametrics.com/vmagent.html#stream-parsing-mode")
seriesLimitPerTarget = flag.Int("promscrape.seriesLimitPerTarget", 0, "Optional limit on the number of unique time series a single scrape target can expose. See https://docs.victoriametrics.com/vmagent.html#cardinality-limiter for more info")
minResponseSizeForStreamParse = flagutil.NewBytes("promscrape.minResponseSizeForStreamParse", 1e6, "The minimum target response size for automatic switching to stream parsing mode, which can reduce memory usage. See https://docs.victoriametrics.com/vmagent.html#stream-parsing-mode")
)
// ScrapeWork represents a unit of work for scraping Prometheus metrics.
//
// It must be immutable during its lifetime, since it is read from concurrently running goroutines.
type ScrapeWork struct {
// Full URL (including query args) for the scrape.
ScrapeURL string
// Interval for scraping the ScrapeURL.
ScrapeInterval time.Duration
// Timeout for scraping the ScrapeURL.
ScrapeTimeout time.Duration
// How to deal with conflicting labels.
// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config
HonorLabels bool
// How to deal with scraped timestamps.
// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config
HonorTimestamps bool
// Whether to deny redirects during requests to scrape config.
DenyRedirects bool
// OriginalLabels contains original labels before relabeling.
//
// These labels are needed for relabeling troubleshooting at /targets page.
OriginalLabels []prompbmarshal.Label
// Labels to add to the scraped metrics.
//
// The list contains at least the following labels according to https://prometheus.io/docs/prometheus/latest/configuration/configuration/#relabel_config
//
// * job
// * __address__
// * __scheme__
// * __metrics_path__
// * __scrape_interval__
// * __scrape_timeout__
// * __param_<name>
// * __meta_*
// * user-defined labels set via `relabel_configs` section in `scrape_config`
//
// See also https://prometheus.io/docs/concepts/jobs_instances/
Labels []prompbmarshal.Label
// ProxyURL HTTP proxy url
ProxyURL proxy.URL
// Auth config for ProxyUR:
ProxyAuthConfig *promauth.Config
// Auth config
AuthConfig *promauth.Config
// Optional `metric_relabel_configs`.
MetricRelabelConfigs *promrelabel.ParsedConfigs
// The maximum number of metrics to scrape after relabeling.
SampleLimit int
// Whether to disable response compression when querying ScrapeURL.
DisableCompression bool
// Whether to disable HTTP keep-alive when querying ScrapeURL.
DisableKeepAlive bool
// Whether to parse target responses in a streaming manner.
StreamParse bool
// The interval for aligning the first scrape.
ScrapeAlignInterval time.Duration
// The offset for the first scrape.
ScrapeOffset time.Duration
// Optional limit on the number of unique series the scrape target can expose.
SeriesLimit int
// The original 'job_name'
jobNameOriginal string
}
func (sw *ScrapeWork) canSwitchToStreamParseMode() bool {
// Deny switching to stream parse mode if `sample_limit` or `series_limit` options are set,
// since these limits cannot be applied in stream parsing mode.
return sw.SampleLimit <= 0 && sw.SeriesLimit <= 0
}
// key returns unique identifier for the given sw.
//
// it can be used for comparing for equality for two ScrapeWork objects.
func (sw *ScrapeWork) key() string {
// Do not take into account OriginalLabels.
key := fmt.Sprintf("ScrapeURL=%s, ScrapeInterval=%s, ScrapeTimeout=%s, HonorLabels=%v, HonorTimestamps=%v, DenyRedirects=%v, Labels=%s, "+
"ProxyURL=%s, ProxyAuthConfig=%s, AuthConfig=%s, MetricRelabelConfigs=%s, SampleLimit=%d, DisableCompression=%v, DisableKeepAlive=%v, StreamParse=%v, "+
"ScrapeAlignInterval=%s, ScrapeOffset=%s, SeriesLimit=%d",
sw.ScrapeURL, sw.ScrapeInterval, sw.ScrapeTimeout, sw.HonorLabels, sw.HonorTimestamps, sw.DenyRedirects, sw.LabelsString(),
sw.ProxyURL.String(), sw.ProxyAuthConfig.String(),
sw.AuthConfig.String(), sw.MetricRelabelConfigs.String(), sw.SampleLimit, sw.DisableCompression, sw.DisableKeepAlive, sw.StreamParse,
sw.ScrapeAlignInterval, sw.ScrapeOffset, sw.SeriesLimit)
return key
}
// Job returns job for the ScrapeWork
func (sw *ScrapeWork) Job() string {
return promrelabel.GetLabelValueByName(sw.Labels, "job")
}
// LabelsString returns labels in Prometheus format for the given sw.
func (sw *ScrapeWork) LabelsString() string {
labelsFinalized := promrelabel.FinalizeLabels(nil, sw.Labels)
return promLabelsString(labelsFinalized)
}
func promLabelsString(labels []prompbmarshal.Label) string {
// Calculate the required memory for storing serialized labels.
n := 2 // for `{...}`
for _, label := range labels {
n += len(label.Name) + len(label.Value)
n += 4 // for `="...",`
}
b := make([]byte, 0, n)
b = append(b, '{')
for i, label := range labels {
b = append(b, label.Name...)
b = append(b, '=')
b = strconv.AppendQuote(b, label.Value)
if i+1 < len(labels) {
b = append(b, ',')
}
}
b = append(b, '}')
return bytesutil.ToUnsafeString(b)
}
type scrapeWork struct {
// Config for the scrape.
Config *ScrapeWork
// ReadData is called for reading the data.
ReadData func(dst []byte) ([]byte, error)
// GetStreamReader is called if Config.StreamParse is set.
GetStreamReader func() (*streamReader, error)
// PushData is called for pushing collected data.
PushData func(wr *prompbmarshal.WriteRequest)
// ScrapeGroup is name of ScrapeGroup that
// scrapeWork belongs to
ScrapeGroup string
tmpRow parser.Row
// This flag is set to true if series_limit is exceeded.
seriesLimitExceeded bool
// labelsHashBuf is used for calculating the hash on series labels
labelsHashBuf []byte
// Optional limiter on the number of unique series per scrape target.
seriesLimiter *bloomfilter.Limiter
// prevBodyLen contains the previous response body length for the given scrape work.
// It is used as a hint in order to reduce memory usage for body buffers.
prevBodyLen int
// prevLabelsLen contains the number labels scraped during the previous scrape.
// It is used as a hint in order to reduce memory usage when parsing scrape responses.
prevLabelsLen int
// lastScrape holds the last response from scrape target.
lastScrape []byte
// lastScrapeCompressed is used for storing the compressed lastScrape between scrapes
// in stream parsing mode in order to reduce memory usage when the lastScrape size
// equals to or exceeds -promscrape.minResponseSizeForStreamParse
lastScrapeCompressed []byte
}
func (sw *scrapeWork) loadLastScrape() {
if len(sw.lastScrapeCompressed) == 0 {
// The lastScrape is already stored in sw.lastScrape
return
}
b, err := encoding.DecompressZSTD(sw.lastScrape[:0], sw.lastScrapeCompressed)
if err != nil {
logger.Panicf("BUG: cannot unpack compressed previous response: %s", err)
}
sw.lastScrape = b
}
func (sw *scrapeWork) storeLastScrape(lastScrape []byte) {
mustCompress := minResponseSizeForStreamParse.N > 0 && len(lastScrape) >= minResponseSizeForStreamParse.N
if mustCompress {
sw.lastScrapeCompressed = encoding.CompressZSTDLevel(sw.lastScrapeCompressed[:0], lastScrape, 1)
sw.lastScrape = nil
} else {
sw.lastScrape = append(sw.lastScrape[:0], lastScrape...)
sw.lastScrapeCompressed = nil
}
}
func (sw *scrapeWork) finalizeLastScrape() {
if len(sw.lastScrapeCompressed) > 0 {
// The compressed lastScrape is available in sw.lastScrapeCompressed.
// Release the memory occupied by sw.lastScrape, so it won't be occupied between scrapes.
sw.lastScrape = nil
}
if len(sw.lastScrape) > 0 {
// Release the memory occupied by sw.lastScrapeCompressed, so it won't be occupied between scrapes.
sw.lastScrapeCompressed = nil
}
}
func (sw *scrapeWork) run(stopCh <-chan struct{}) {
var randSleep uint64
scrapeInterval := sw.Config.ScrapeInterval
scrapeAlignInterval := sw.Config.ScrapeAlignInterval
scrapeOffset := sw.Config.ScrapeOffset
if scrapeOffset > 0 {
scrapeAlignInterval = scrapeInterval
}
if scrapeAlignInterval <= 0 {
// Calculate start time for the first scrape from ScrapeURL and labels.
// This should spread load when scraping many targets with different
// scrape urls and labels.
// This also makes consistent scrape times across restarts
// for a target with the same ScrapeURL and labels.
key := fmt.Sprintf("ScrapeURL=%s, Labels=%s", sw.Config.ScrapeURL, sw.Config.LabelsString())
h := uint32(xxhash.Sum64(bytesutil.ToUnsafeBytes(key)))
randSleep = uint64(float64(scrapeInterval) * (float64(h) / (1 << 32)))
sleepOffset := uint64(time.Now().UnixNano()) % uint64(scrapeInterval)
if randSleep < sleepOffset {
randSleep += uint64(scrapeInterval)
}
randSleep -= sleepOffset
} else {
d := uint64(scrapeAlignInterval)
randSleep = d - uint64(time.Now().UnixNano())%d
if scrapeOffset > 0 {
randSleep += uint64(scrapeOffset)
}
randSleep %= uint64(scrapeInterval)
}
timer := timerpool.Get(time.Duration(randSleep))
var timestamp int64
var ticker *time.Ticker
select {
case <-stopCh:
timerpool.Put(timer)
return
case <-timer.C:
timerpool.Put(timer)
ticker = time.NewTicker(scrapeInterval)
timestamp = time.Now().UnixNano() / 1e6
sw.scrapeAndLogError(timestamp, timestamp)
}
defer ticker.Stop()
for {
timestamp += scrapeInterval.Milliseconds()
select {
case <-stopCh:
t := time.Now().UnixNano() / 1e6
sw.sendStaleSeries("", t, true)
if sw.seriesLimiter != nil {
sw.seriesLimiter.MustStop()
}
return
case tt := <-ticker.C:
t := tt.UnixNano() / 1e6
if d := math.Abs(float64(t - timestamp)); d > 0 && d/float64(scrapeInterval.Milliseconds()) > 0.1 {
// Too big jitter. Adjust timestamp
timestamp = t
}
sw.scrapeAndLogError(timestamp, t)
}
}
}
func (sw *scrapeWork) logError(s string) {
if !*suppressScrapeErrors {
logger.ErrorfSkipframes(1, "error when scraping %q from job %q with labels %s: %s; "+
"scrape errors can be disabled by -promscrape.suppressScrapeErrors command-line flag",
sw.Config.ScrapeURL, sw.Config.Job(), sw.Config.LabelsString(), s)
}
}
func (sw *scrapeWork) scrapeAndLogError(scrapeTimestamp, realTimestamp int64) {
if err := sw.scrapeInternal(scrapeTimestamp, realTimestamp); err != nil && !*suppressScrapeErrors {
logger.Errorf("error when scraping %q from job %q with labels %s: %s", sw.Config.ScrapeURL, sw.Config.Job(), sw.Config.LabelsString(), err)
}
}
var (
scrapeDuration = metrics.NewHistogram("vm_promscrape_scrape_duration_seconds")
scrapeResponseSize = metrics.NewHistogram("vm_promscrape_scrape_response_size_bytes")
scrapedSamples = metrics.NewHistogram("vm_promscrape_scraped_samples")
scrapesSkippedBySampleLimit = metrics.NewCounter("vm_promscrape_scrapes_skipped_by_sample_limit_total")
scrapesFailed = metrics.NewCounter("vm_promscrape_scrapes_failed_total")
pushDataDuration = metrics.NewHistogram("vm_promscrape_push_data_duration_seconds")
)
func (sw *scrapeWork) mustSwitchToStreamParseMode(responseSize int) bool {
if minResponseSizeForStreamParse.N <= 0 {
return false
}
return sw.Config.canSwitchToStreamParseMode() && responseSize >= minResponseSizeForStreamParse.N
}
func (sw *scrapeWork) scrapeInternal(scrapeTimestamp, realTimestamp int64) error {
if *streamParse || sw.Config.StreamParse || sw.mustSwitchToStreamParseMode(sw.prevBodyLen) {
// Read data from scrape targets in streaming manner.
// This case is optimized for targets exposing more than ten thousand of metrics per target.
return sw.scrapeStream(scrapeTimestamp, realTimestamp)
}
// Common case: read all the data from scrape target to memory (body) and then process it.
// This case should work more optimally than stream parse code for common case when scrape target exposes
2020-11-26 12:33:46 +01:00
// up to a few thousand metrics.
body := leveledbytebufferpool.Get(sw.prevBodyLen)
var err error
body.B, err = sw.ReadData(body.B[:0])
endTimestamp := time.Now().UnixNano() / 1e6
duration := float64(endTimestamp-realTimestamp) / 1e3
scrapeDuration.Update(duration)
scrapeResponseSize.Update(float64(len(body.B)))
up := 1
wc := writeRequestCtxPool.Get(sw.prevLabelsLen)
sw.loadLastScrape()
bodyString := bytesutil.ToUnsafeString(body.B)
lastScrape := bytesutil.ToUnsafeString(sw.lastScrape)
areIdenticalSeries := parser.AreIdenticalSeriesFast(lastScrape, bodyString)
if err != nil {
up = 0
scrapesFailed.Inc()
} else {
wc.rows.UnmarshalWithErrLogger(bodyString, sw.logError)
}
srcRows := wc.rows.Rows
samplesScraped := len(srcRows)
scrapedSamples.Update(float64(samplesScraped))
for i := range srcRows {
sw.addRowToTimeseries(wc, &srcRows[i], scrapeTimestamp, true)
}
samplesPostRelabeling := len(wc.writeRequest.Timeseries)
if sw.Config.SampleLimit > 0 && samplesPostRelabeling > sw.Config.SampleLimit {
wc.resetNoRows()
up = 0
scrapesSkippedBySampleLimit.Inc()
err = fmt.Errorf("the response from %q exceeds sample_limit=%d; "+
"either reduce the sample count for the target or increase sample_limit", sw.Config.ScrapeURL, sw.Config.SampleLimit)
}
if up == 0 {
bodyString = ""
}
seriesAdded := 0
if !areIdenticalSeries {
// The returned value for seriesAdded may be bigger than the real number of added series
// if some series were removed during relabeling.
// This is a trade-off between performance and accuracy.
seriesAdded = sw.getSeriesAdded(bodyString)
}
if sw.seriesLimitExceeded || !areIdenticalSeries {
if sw.applySeriesLimit(wc) {
sw.seriesLimitExceeded = true
}
}
sw.addAutoTimeseries(wc, "up", float64(up), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_duration_seconds", duration, scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_samples_scraped", float64(samplesScraped), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_samples_post_metric_relabeling", float64(samplesPostRelabeling), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_series_added", float64(seriesAdded), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_timeout_seconds", sw.Config.ScrapeTimeout.Seconds(), scrapeTimestamp)
sw.pushData(&wc.writeRequest)
sw.prevLabelsLen = len(wc.labels)
sw.prevBodyLen = len(bodyString)
wc.reset()
mustSwitchToStreamParse := sw.mustSwitchToStreamParseMode(len(bodyString))
if !mustSwitchToStreamParse {
// Return wc to the pool if the parsed response size was smaller than -promscrape.minResponseSizeForStreamParse
// This should reduce memory usage when scraping targets with big responses.
writeRequestCtxPool.Put(wc)
}
// body must be released only after wc is released, since wc refers to body.
if !areIdenticalSeries {
sw.sendStaleSeries(bodyString, scrapeTimestamp, false)
sw.storeLastScrape(body.B)
}
sw.finalizeLastScrape()
if !mustSwitchToStreamParse {
// Return wc to the pool only if its size is smaller than -promscrape.minResponseSizeForStreamParse
// This should reduce memory usage when scraping targets which return big responses.
leveledbytebufferpool.Put(body)
}
tsmGlobal.Update(sw.Config, sw.ScrapeGroup, up == 1, realTimestamp, int64(duration*1000), samplesScraped, err)
return err
}
func (sw *scrapeWork) pushData(wr *prompbmarshal.WriteRequest) {
startTime := time.Now()
sw.PushData(wr)
pushDataDuration.UpdateDuration(startTime)
}
type streamBodyReader struct {
sr *streamReader
body []byte
}
func (sbr *streamBodyReader) Read(b []byte) (int, error) {
n, err := sbr.sr.Read(b)
sbr.body = append(sbr.body, b[:n]...)
return n, err
}
func (sw *scrapeWork) scrapeStream(scrapeTimestamp, realTimestamp int64) error {
samplesScraped := 0
samplesPostRelabeling := 0
wc := writeRequestCtxPool.Get(sw.prevLabelsLen)
// Do not pool sbr and do not pre-allocate sbr.body in order to reduce memory usage when scraping big responses.
sbr := &streamBodyReader{}
sr, err := sw.GetStreamReader()
if err != nil {
err = fmt.Errorf("cannot read data: %s", err)
} else {
var mu sync.Mutex
sbr.sr = sr
err = parser.ParseStream(sbr, scrapeTimestamp, false, func(rows []parser.Row) error {
mu.Lock()
defer mu.Unlock()
samplesScraped += len(rows)
for i := range rows {
sw.addRowToTimeseries(wc, &rows[i], scrapeTimestamp, true)
}
// Push the collected rows to sw before returning from the callback, since they cannot be held
// after returning from the callback - this will result in data race.
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/825#issuecomment-723198247
samplesPostRelabeling += len(wc.writeRequest.Timeseries)
if sw.Config.SampleLimit > 0 && samplesPostRelabeling > sw.Config.SampleLimit {
wc.resetNoRows()
scrapesSkippedBySampleLimit.Inc()
return fmt.Errorf("the response from %q exceeds sample_limit=%d; "+
"either reduce the sample count for the target or increase sample_limit", sw.Config.ScrapeURL, sw.Config.SampleLimit)
}
sw.pushData(&wc.writeRequest)
wc.resetNoRows()
return nil
}, sw.logError)
sr.MustClose()
}
sw.loadLastScrape()
bodyString := bytesutil.ToUnsafeString(sbr.body)
lastScrape := bytesutil.ToUnsafeString(sw.lastScrape)
areIdenticalSeries := parser.AreIdenticalSeriesFast(lastScrape, bodyString)
scrapedSamples.Update(float64(samplesScraped))
endTimestamp := time.Now().UnixNano() / 1e6
duration := float64(endTimestamp-realTimestamp) / 1e3
scrapeDuration.Update(duration)
scrapeResponseSize.Update(float64(len(bodyString)))
up := 1
if err != nil {
if samplesScraped == 0 {
up = 0
}
scrapesFailed.Inc()
}
seriesAdded := 0
if !areIdenticalSeries {
// The returned value for seriesAdded may be bigger than the real number of added series
// if some series were removed during relabeling.
// This is a trade-off between performance and accuracy.
seriesAdded = sw.getSeriesAdded(bodyString)
}
sw.addAutoTimeseries(wc, "up", float64(up), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_duration_seconds", duration, scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_samples_scraped", float64(samplesScraped), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_samples_post_metric_relabeling", float64(samplesPostRelabeling), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_series_added", float64(seriesAdded), scrapeTimestamp)
sw.addAutoTimeseries(wc, "scrape_timeout_seconds", sw.Config.ScrapeTimeout.Seconds(), scrapeTimestamp)
sw.pushData(&wc.writeRequest)
sw.prevLabelsLen = len(wc.labels)
sw.prevBodyLen = len(bodyString)
wc.reset()
writeRequestCtxPool.Put(wc)
if !areIdenticalSeries {
sw.sendStaleSeries(bodyString, scrapeTimestamp, false)
sw.storeLastScrape(sbr.body)
}
sw.finalizeLastScrape()
tsmGlobal.Update(sw.Config, sw.ScrapeGroup, up == 1, realTimestamp, int64(duration*1000), samplesScraped, err)
// Do not track active series in streaming mode, since this may need too big amounts of memory
// when the target exports too big number of metrics.
return err
}
// leveledWriteRequestCtxPool allows reducing memory usage when writeRequesCtx
// structs contain mixed number of labels.
//
// Its logic has been copied from leveledbytebufferpool.
type leveledWriteRequestCtxPool struct {
pools [13]sync.Pool
}
func (lwp *leveledWriteRequestCtxPool) Get(labelsCapacity int) *writeRequestCtx {
id, capacityNeeded := lwp.getPoolIDAndCapacity(labelsCapacity)
for i := 0; i < 2; i++ {
if id < 0 || id >= len(lwp.pools) {
break
}
if v := lwp.pools[id].Get(); v != nil {
return v.(*writeRequestCtx)
}
id++
}
return &writeRequestCtx{
labels: make([]prompbmarshal.Label, 0, capacityNeeded),
}
}
func (lwp *leveledWriteRequestCtxPool) Put(wc *writeRequestCtx) {
capacity := cap(wc.labels)
id, poolCapacity := lwp.getPoolIDAndCapacity(capacity)
if capacity <= poolCapacity {
wc.reset()
lwp.pools[id].Put(wc)
}
}
func (lwp *leveledWriteRequestCtxPool) getPoolIDAndCapacity(size int) (int, int) {
size--
if size < 0 {
size = 0
}
size >>= 3
id := bits.Len(uint(size))
if id >= len(lwp.pools) {
id = len(lwp.pools) - 1
}
return id, (1 << (id + 3))
}
type writeRequestCtx struct {
rows parser.Rows
writeRequest prompbmarshal.WriteRequest
labels []prompbmarshal.Label
samples []prompbmarshal.Sample
}
func (wc *writeRequestCtx) reset() {
wc.rows.Reset()
wc.resetNoRows()
}
func (wc *writeRequestCtx) resetNoRows() {
prompbmarshal.ResetWriteRequest(&wc.writeRequest)
wc.labels = wc.labels[:0]
wc.samples = wc.samples[:0]
}
var writeRequestCtxPool leveledWriteRequestCtxPool
func (sw *scrapeWork) getSeriesAdded(currScrape string) int {
if currScrape == "" {
return 0
}
lastScrape := bytesutil.ToUnsafeString(sw.lastScrape)
bodyString := parser.GetRowsDiff(currScrape, lastScrape)
return strings.Count(bodyString, "\n")
}
func (sw *scrapeWork) applySeriesLimit(wc *writeRequestCtx) bool {
seriesLimit := *seriesLimitPerTarget
if sw.Config.SeriesLimit > 0 {
seriesLimit = sw.Config.SeriesLimit
}
if sw.seriesLimiter == nil && seriesLimit > 0 {
sw.seriesLimiter = bloomfilter.NewLimiter(seriesLimit, 24*time.Hour)
}
hsl := sw.seriesLimiter
if hsl == nil {
return false
}
dstSeries := wc.writeRequest.Timeseries[:0]
job := sw.Config.Job()
limitExceeded := false
for _, ts := range wc.writeRequest.Timeseries {
h := sw.getLabelsHash(ts.Labels)
if !hsl.Add(h) {
// The limit on the number of hourly unique series per scrape target has been exceeded.
// Drop the metric.
metrics.GetOrCreateCounter(fmt.Sprintf(`promscrape_series_limit_rows_dropped_total{scrape_job_original=%q,scrape_job=%q,scrape_target=%q}`,
sw.Config.jobNameOriginal, job, sw.Config.ScrapeURL)).Inc()
limitExceeded = true
continue
}
dstSeries = append(dstSeries, ts)
}
wc.writeRequest.Timeseries = dstSeries
return limitExceeded
}
func (sw *scrapeWork) sendStaleSeries(currScrape string, timestamp int64, addAutoSeries bool) {
if *noStaleMarkers {
return
}
lastScrape := bytesutil.ToUnsafeString(sw.lastScrape)
bodyString := lastScrape
if currScrape != "" {
bodyString = parser.GetRowsDiff(lastScrape, currScrape)
}
wc := &writeRequestCtx{}
if bodyString != "" {
wc.rows.Unmarshal(bodyString)
srcRows := wc.rows.Rows
for i := range srcRows {
sw.addRowToTimeseries(wc, &srcRows[i], timestamp, true)
}
}
if addAutoSeries {
sw.addAutoTimeseries(wc, "up", 0, timestamp)
sw.addAutoTimeseries(wc, "scrape_duration_seconds", 0, timestamp)
sw.addAutoTimeseries(wc, "scrape_samples_scraped", 0, timestamp)
sw.addAutoTimeseries(wc, "scrape_samples_post_metric_relabeling", 0, timestamp)
sw.addAutoTimeseries(wc, "scrape_series_added", 0, timestamp)
}
series := wc.writeRequest.Timeseries
if len(series) == 0 {
return
}
// Substitute all the values with Prometheus stale markers.
for _, tss := range series {
samples := tss.Samples
for i := range samples {
samples[i].Value = decimal.StaleNaN
}
}
sw.pushData(&wc.writeRequest)
}
func (sw *scrapeWork) getLabelsHash(labels []prompbmarshal.Label) uint64 {
// It is OK if there will be hash collisions for distinct sets of labels,
// since the accuracy for `scrape_series_added` metric may be lower than 100%.
b := sw.labelsHashBuf[:0]
for _, label := range labels {
b = append(b, label.Name...)
b = append(b, label.Value...)
}
sw.labelsHashBuf = b
return xxhash.Sum64(b)
}
// addAutoTimeseries adds automatically generated time series with the given name, value and timestamp.
//
// See https://prometheus.io/docs/concepts/jobs_instances/#automatically-generated-labels-and-time-series
func (sw *scrapeWork) addAutoTimeseries(wc *writeRequestCtx, name string, value float64, timestamp int64) {
sw.tmpRow.Metric = name
sw.tmpRow.Tags = nil
sw.tmpRow.Value = value
sw.tmpRow.Timestamp = timestamp
sw.addRowToTimeseries(wc, &sw.tmpRow, timestamp, false)
}
func (sw *scrapeWork) addRowToTimeseries(wc *writeRequestCtx, r *parser.Row, timestamp int64, needRelabel bool) {
labelsLen := len(wc.labels)
wc.labels = appendLabels(wc.labels, r.Metric, r.Tags, sw.Config.Labels, sw.Config.HonorLabels)
if needRelabel {
wc.labels = sw.Config.MetricRelabelConfigs.Apply(wc.labels, labelsLen, true)
} else {
wc.labels = promrelabel.FinalizeLabels(wc.labels[:labelsLen], wc.labels[labelsLen:])
promrelabel.SortLabels(wc.labels[labelsLen:])
}
if len(wc.labels) == labelsLen {
// Skip row without labels.
return
}
sampleTimestamp := r.Timestamp
if !sw.Config.HonorTimestamps || sampleTimestamp == 0 {
sampleTimestamp = timestamp
}
wc.samples = append(wc.samples, prompbmarshal.Sample{
Value: r.Value,
Timestamp: sampleTimestamp,
})
wr := &wc.writeRequest
wr.Timeseries = append(wr.Timeseries, prompbmarshal.TimeSeries{
Labels: wc.labels[labelsLen:],
Samples: wc.samples[len(wc.samples)-1:],
})
}
func appendLabels(dst []prompbmarshal.Label, metric string, src []parser.Tag, extraLabels []prompbmarshal.Label, honorLabels bool) []prompbmarshal.Label {
dstLen := len(dst)
dst = append(dst, prompbmarshal.Label{
Name: "__name__",
Value: metric,
})
for i := range src {
tag := &src[i]
dst = append(dst, prompbmarshal.Label{
Name: tag.Key,
Value: tag.Value,
})
}
dst = append(dst, extraLabels...)
labels := dst[dstLen:]
if len(labels) <= 1 {
// Fast path - only a single label.
return dst
}
// de-duplicate labels
dstLabels := labels[:0]
for i := range labels {
label := &labels[i]
prevLabel := promrelabel.GetLabelByName(dstLabels, label.Name)
if prevLabel == nil {
dstLabels = append(dstLabels, *label)
continue
}
if honorLabels {
// Skip the extra label with the same name.
continue
}
// Rename the prevLabel to "exported_" + label.Name.
// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config
exportedName := "exported_" + label.Name
if promrelabel.GetLabelByName(dstLabels, exportedName) != nil {
// Override duplicate with the current label.
*prevLabel = *label
continue
}
prevLabel.Name = exportedName
dstLabels = append(dstLabels, *label)
}
return dst[:dstLen+len(dstLabels)]
}