prometheus/retrieval/scrape.go

1009 lines
26 KiB
Go

// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package retrieval
import (
"bufio"
"bytes"
"compress/gzip"
"fmt"
"io"
"math"
"net/http"
"sync"
"time"
"unsafe"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/log"
"github.com/prometheus/common/version"
"golang.org/x/net/context"
"golang.org/x/net/context/ctxhttp"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/pkg/labels"
"github.com/prometheus/prometheus/pkg/textparse"
"github.com/prometheus/prometheus/pkg/timestamp"
"github.com/prometheus/prometheus/pkg/value"
"github.com/prometheus/prometheus/storage"
"github.com/prometheus/prometheus/util/httputil"
)
const (
scrapeHealthMetricName = "up"
scrapeDurationMetricName = "scrape_duration_seconds"
scrapeSamplesMetricName = "scrape_samples_scraped"
samplesPostRelabelMetricName = "scrape_samples_post_metric_relabeling"
)
var (
targetIntervalLength = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "prometheus_target_interval_length_seconds",
Help: "Actual intervals between scrapes.",
Objectives: map[float64]float64{0.01: 0.001, 0.05: 0.005, 0.5: 0.05, 0.90: 0.01, 0.99: 0.001},
},
[]string{"interval"},
)
targetReloadIntervalLength = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "prometheus_target_reload_length_seconds",
Help: "Actual interval to reload the scrape pool with a given configuration.",
Objectives: map[float64]float64{0.01: 0.001, 0.05: 0.005, 0.5: 0.05, 0.90: 0.01, 0.99: 0.001},
},
[]string{"interval"},
)
targetSyncIntervalLength = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "prometheus_target_sync_length_seconds",
Help: "Actual interval to sync the scrape pool.",
Objectives: map[float64]float64{0.01: 0.001, 0.05: 0.005, 0.5: 0.05, 0.90: 0.01, 0.99: 0.001},
},
[]string{"scrape_job"},
)
targetScrapePoolSyncsCounter = prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "prometheus_target_scrape_pool_sync_total",
Help: "Total number of syncs that were executed on a scrape pool.",
},
[]string{"scrape_job"},
)
targetScrapeSampleLimit = prometheus.NewCounter(
prometheus.CounterOpts{
Name: "prometheus_target_scrapes_exceeded_sample_limit_total",
Help: "Total number of scrapes that hit the sample limit and were rejected.",
},
)
targetScrapeSampleDuplicate = prometheus.NewCounter(
prometheus.CounterOpts{
Name: "prometheus_target_scrapes_sample_duplicate_timestamp_total",
Help: "Total number of samples rejected due to duplicate timestamps but different values",
},
)
targetScrapeSampleOutOfOrder = prometheus.NewCounter(
prometheus.CounterOpts{
Name: "prometheus_target_scrapes_sample_out_of_order_total",
Help: "Total number of samples rejected due to not being out of the expected order",
},
)
targetScrapeSampleOutOfBounds = prometheus.NewCounter(
prometheus.CounterOpts{
Name: "prometheus_target_scrapes_sample_out_of_bounds_total",
Help: "Total number of samples rejected due to timestamp falling outside of the time bounds",
},
)
)
func init() {
prometheus.MustRegister(targetIntervalLength)
prometheus.MustRegister(targetReloadIntervalLength)
prometheus.MustRegister(targetSyncIntervalLength)
prometheus.MustRegister(targetScrapePoolSyncsCounter)
prometheus.MustRegister(targetScrapeSampleLimit)
prometheus.MustRegister(targetScrapeSampleDuplicate)
prometheus.MustRegister(targetScrapeSampleOutOfOrder)
prometheus.MustRegister(targetScrapeSampleOutOfBounds)
}
// scrapePool manages scrapes for sets of targets.
type scrapePool struct {
appendable Appendable
ctx context.Context
mtx sync.RWMutex
config *config.ScrapeConfig
client *http.Client
// Targets and loops must always be synchronized to have the same
// set of hashes.
targets map[uint64]*Target
loops map[uint64]loop
// Constructor for new scrape loops. This is settable for testing convenience.
newLoop func(context.Context, scraper, func() storage.Appender, func() storage.Appender, log.Logger) loop
logger log.Logger
maxAheadTime time.Duration
}
func newScrapePool(ctx context.Context, cfg *config.ScrapeConfig, app Appendable, logger log.Logger) *scrapePool {
client, err := httputil.NewClientFromConfig(cfg.HTTPClientConfig)
if err != nil {
// Any errors that could occur here should be caught during config validation.
logger.Errorf("Error creating HTTP client for job %q: %s", cfg.JobName, err)
}
newLoop := func(
ctx context.Context,
s scraper,
app, reportApp func() storage.Appender,
l log.Logger,
) loop {
return newScrapeLoop(ctx, s, app, reportApp, l)
}
return &scrapePool{
appendable: app,
config: cfg,
ctx: ctx,
client: client,
targets: map[uint64]*Target{},
loops: map[uint64]loop{},
newLoop: newLoop,
logger: logger,
maxAheadTime: 10 * time.Minute,
}
}
// stop terminates all scrape loops and returns after they all terminated.
func (sp *scrapePool) stop() {
var wg sync.WaitGroup
sp.mtx.Lock()
defer sp.mtx.Unlock()
for fp, l := range sp.loops {
wg.Add(1)
go func(l loop) {
l.stop()
wg.Done()
}(l)
delete(sp.loops, fp)
delete(sp.targets, fp)
}
wg.Wait()
}
// reload the scrape pool with the given scrape configuration. The target state is preserved
// but all scrape loops are restarted with the new scrape configuration.
// This method returns after all scrape loops that were stopped have stopped scraping.
func (sp *scrapePool) reload(cfg *config.ScrapeConfig) {
start := time.Now()
sp.mtx.Lock()
defer sp.mtx.Unlock()
client, err := httputil.NewClientFromConfig(cfg.HTTPClientConfig)
if err != nil {
// Any errors that could occur here should be caught during config validation.
sp.logger.Errorf("Error creating HTTP client for job %q: %s", cfg.JobName, err)
}
sp.config = cfg
sp.client = client
var (
wg sync.WaitGroup
interval = time.Duration(sp.config.ScrapeInterval)
timeout = time.Duration(sp.config.ScrapeTimeout)
)
for fp, oldLoop := range sp.loops {
var (
t = sp.targets[fp]
s = &targetScraper{Target: t, client: sp.client, timeout: timeout}
newLoop = sp.newLoop(sp.ctx, s,
func() storage.Appender {
return sp.sampleAppender(t)
},
func() storage.Appender {
return sp.reportAppender(t)
},
sp.logger.With("target", t.labels.String()),
)
)
wg.Add(1)
go func(oldLoop, newLoop loop) {
oldLoop.stop()
wg.Done()
go newLoop.run(interval, timeout, nil)
}(oldLoop, newLoop)
sp.loops[fp] = newLoop
}
wg.Wait()
targetReloadIntervalLength.WithLabelValues(interval.String()).Observe(
time.Since(start).Seconds(),
)
}
// Sync converts target groups into actual scrape targets and synchronizes
// the currently running scraper with the resulting set.
func (sp *scrapePool) Sync(tgs []*config.TargetGroup) {
start := time.Now()
var all []*Target
for _, tg := range tgs {
targets, err := targetsFromGroup(tg, sp.config)
if err != nil {
sp.logger.With("err", err).Error("creating targets failed")
continue
}
all = append(all, targets...)
}
sp.sync(all)
targetSyncIntervalLength.WithLabelValues(sp.config.JobName).Observe(
time.Since(start).Seconds(),
)
targetScrapePoolSyncsCounter.WithLabelValues(sp.config.JobName).Inc()
}
// sync takes a list of potentially duplicated targets, deduplicates them, starts
// scrape loops for new targets, and stops scrape loops for disappeared targets.
// It returns after all stopped scrape loops terminated.
func (sp *scrapePool) sync(targets []*Target) {
sp.mtx.Lock()
defer sp.mtx.Unlock()
var (
uniqueTargets = map[uint64]struct{}{}
interval = time.Duration(sp.config.ScrapeInterval)
timeout = time.Duration(sp.config.ScrapeTimeout)
)
for _, t := range targets {
t := t
hash := t.hash()
uniqueTargets[hash] = struct{}{}
if _, ok := sp.targets[hash]; !ok {
s := &targetScraper{Target: t, client: sp.client, timeout: timeout}
l := sp.newLoop(sp.ctx, s,
func() storage.Appender {
return sp.sampleAppender(t)
},
func() storage.Appender {
return sp.reportAppender(t)
},
sp.logger.With("target", t.labels.String()),
)
sp.targets[hash] = t
sp.loops[hash] = l
go l.run(interval, timeout, nil)
}
}
var wg sync.WaitGroup
// Stop and remove old targets and scraper loops.
for hash := range sp.targets {
if _, ok := uniqueTargets[hash]; !ok {
wg.Add(1)
go func(l loop) {
l.stop()
wg.Done()
}(sp.loops[hash])
delete(sp.loops, hash)
delete(sp.targets, hash)
}
}
// Wait for all potentially stopped scrapers to terminate.
// This covers the case of flapping targets. If the server is under high load, a new scraper
// may be active and tries to insert. The old scraper that didn't terminate yet could still
// be inserting a previous sample set.
wg.Wait()
}
// sampleAppender returns an appender for ingested samples from the target.
func (sp *scrapePool) sampleAppender(target *Target) storage.Appender {
app, err := sp.appendable.Appender()
if err != nil {
panic(err)
}
if sp.maxAheadTime > 0 {
app = &timeLimitAppender{
Appender: app,
maxTime: timestamp.FromTime(time.Now().Add(sp.maxAheadTime)),
}
}
// The limit is applied after metrics are potentially dropped via relabeling.
if sp.config.SampleLimit > 0 {
app = &limitAppender{
Appender: app,
limit: int(sp.config.SampleLimit),
}
}
// The relabelAppender has to be inside the label-modifying appenders
// so the relabeling rules are applied to the correct label set.
if mrc := sp.config.MetricRelabelConfigs; len(mrc) > 0 {
app = relabelAppender{
Appender: app,
relabelings: mrc,
}
}
if sp.config.HonorLabels {
app = honorLabelsAppender{
Appender: app,
labels: target.Labels(),
}
} else {
app = ruleLabelsAppender{
Appender: app,
labels: target.Labels(),
}
}
return app
}
// reportAppender returns an appender for reporting samples for the target.
func (sp *scrapePool) reportAppender(target *Target) storage.Appender {
app, err := sp.appendable.Appender()
if err != nil {
panic(err)
}
return ruleLabelsAppender{
Appender: app,
labels: target.Labels(),
}
}
// A scraper retrieves samples and accepts a status report at the end.
type scraper interface {
scrape(ctx context.Context, w io.Writer) error
report(start time.Time, dur time.Duration, err error)
offset(interval time.Duration) time.Duration
}
// targetScraper implements the scraper interface for a target.
type targetScraper struct {
*Target
client *http.Client
req *http.Request
timeout time.Duration
gzipr *gzip.Reader
buf *bufio.Reader
}
const acceptHeader = `application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited;q=0.7,text/plain;version=0.0.4;q=0.3,*/*;q=0.1`
var userAgentHeader = fmt.Sprintf("Prometheus/%s", version.Version)
func (s *targetScraper) scrape(ctx context.Context, w io.Writer) error {
if s.req == nil {
req, err := http.NewRequest("GET", s.URL().String(), nil)
if err != nil {
return err
}
// Disable accept header to always negotiate for text format.
// req.Header.Add("Accept", acceptHeader)
req.Header.Add("Accept-Encoding", "gzip")
req.Header.Set("User-Agent", userAgentHeader)
req.Header.Set("X-Prometheus-Scrape-Timeout-Seconds", fmt.Sprintf("%f", s.timeout.Seconds()))
s.req = req
}
resp, err := ctxhttp.Do(ctx, s.client, s.req)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return fmt.Errorf("server returned HTTP status %s", resp.Status)
}
if resp.Header.Get("Content-Encoding") != "gzip" {
_, err = io.Copy(w, resp.Body)
return err
}
if s.gzipr == nil {
s.buf = bufio.NewReader(resp.Body)
s.gzipr, err = gzip.NewReader(s.buf)
if err != nil {
return err
}
} else {
s.buf.Reset(resp.Body)
s.gzipr.Reset(s.buf)
}
_, err = io.Copy(w, s.gzipr)
s.gzipr.Close()
return err
}
// A loop can run and be stopped again. It must not be reused after it was stopped.
type loop interface {
run(interval, timeout time.Duration, errc chan<- error)
stop()
}
type lsetCacheEntry struct {
metric string
lset labels.Labels
hash uint64
}
type refEntry struct {
ref string
lastIter uint64
}
type scrapeLoop struct {
scraper scraper
l log.Logger
cache *scrapeCache
appender func() storage.Appender
reportAppender func() storage.Appender
ctx context.Context
scrapeCtx context.Context
cancel func()
stopped chan struct{}
}
// scrapeCache tracks mappings of exposed metric strings to label sets and
// storage references. Additionally, it tracks staleness of series between
// scrapes.
type scrapeCache struct {
iter uint64 // Current scrape iteration.
refs map[string]*refEntry // Parsed string to ref.
lsets map[string]*lsetCacheEntry // Ref to labelset and string.
// seriesCur and seriesPrev store the labels of series that were seen
// in the current and previous scrape.
// We hold two maps and swap them out to save allocations.
seriesCur map[uint64]labels.Labels
seriesPrev map[uint64]labels.Labels
}
func newScrapeCache() *scrapeCache {
return &scrapeCache{
refs: map[string]*refEntry{},
lsets: map[string]*lsetCacheEntry{},
seriesCur: map[uint64]labels.Labels{},
seriesPrev: map[uint64]labels.Labels{},
}
}
func (c *scrapeCache) iterDone() {
// refCache and lsetCache may grow over time through series churn
// or multiple string representations of the same metric. Clean up entries
// that haven't appeared in the last scrape.
for s, e := range c.refs {
if e.lastIter < c.iter {
delete(c.refs, s)
delete(c.lsets, e.ref)
}
}
// Swap current and previous series.
c.seriesPrev, c.seriesCur = c.seriesCur, c.seriesPrev
// We have to delete every single key in the map.
for k := range c.seriesCur {
delete(c.seriesCur, k)
}
c.iter++
}
func (c *scrapeCache) getRef(met string) (string, bool) {
e, ok := c.refs[met]
if !ok {
return "", false
}
e.lastIter = c.iter
return e.ref, true
}
func (c *scrapeCache) addRef(met, ref string, lset labels.Labels, hash uint64) {
if ref == "" {
return
}
// Clean up the label set cache before overwriting the ref for a previously seen
// metric representation. It won't be caught by the cleanup in iterDone otherwise.
if e, ok := c.refs[met]; ok {
delete(c.lsets, e.ref)
}
c.refs[met] = &refEntry{ref: ref, lastIter: c.iter}
// met is the raw string the metric was ingested as. The label set is not ordered
// and thus it's not suitable to uniquely identify cache entries.
// We store a hash over the label set instead.
c.lsets[ref] = &lsetCacheEntry{metric: met, lset: lset, hash: hash}
}
func (c *scrapeCache) trackStaleness(hash uint64, lset labels.Labels) {
c.seriesCur[hash] = lset
}
func (c *scrapeCache) forEachStale(f func(labels.Labels) bool) {
for h, lset := range c.seriesPrev {
if _, ok := c.seriesCur[h]; !ok {
if !f(lset) {
break
}
}
}
}
func newScrapeLoop(
ctx context.Context,
sc scraper,
app, reportApp func() storage.Appender,
l log.Logger,
) *scrapeLoop {
if l == nil {
l = log.Base()
}
sl := &scrapeLoop{
scraper: sc,
appender: app,
cache: newScrapeCache(),
reportAppender: reportApp,
stopped: make(chan struct{}),
ctx: ctx,
l: l,
}
sl.scrapeCtx, sl.cancel = context.WithCancel(ctx)
return sl
}
func (sl *scrapeLoop) run(interval, timeout time.Duration, errc chan<- error) {
select {
case <-time.After(sl.scraper.offset(interval)):
// Continue after a scraping offset.
case <-sl.scrapeCtx.Done():
close(sl.stopped)
return
}
var last time.Time
ticker := time.NewTicker(interval)
defer ticker.Stop()
buf := bytes.NewBuffer(make([]byte, 0, 16000))
mainLoop:
for {
buf.Reset()
select {
case <-sl.ctx.Done():
close(sl.stopped)
return
case <-sl.scrapeCtx.Done():
break mainLoop
default:
}
var (
start = time.Now()
scrapeCtx, cancel = context.WithTimeout(sl.ctx, timeout)
)
// Only record after the first scrape.
if !last.IsZero() {
targetIntervalLength.WithLabelValues(interval.String()).Observe(
time.Since(last).Seconds(),
)
}
scrapeErr := sl.scraper.scrape(scrapeCtx, buf)
cancel()
var b []byte
if scrapeErr == nil {
b = buf.Bytes()
} else if errc != nil {
errc <- scrapeErr
}
// A failed scrape is the same as an empty scrape,
// we still call sl.append to trigger stale markers.
total, added, appErr := sl.append(b, start)
if appErr != nil {
sl.l.With("err", appErr).Warn("append failed")
// The append failed, probably due to a parse error or sample limit.
// Call sl.append again with an empty scrape to trigger stale markers.
if _, _, err := sl.append([]byte{}, start); err != nil {
sl.l.With("err", err).Error("append failed")
}
}
if scrapeErr == nil {
scrapeErr = appErr
}
sl.report(start, time.Since(start), total, added, scrapeErr)
last = start
select {
case <-sl.ctx.Done():
close(sl.stopped)
return
case <-sl.scrapeCtx.Done():
break mainLoop
case <-ticker.C:
}
}
close(sl.stopped)
sl.endOfRunStaleness(last, ticker, interval)
}
func (sl *scrapeLoop) endOfRunStaleness(last time.Time, ticker *time.Ticker, interval time.Duration) {
// Scraping has stopped. We want to write stale markers but
// the target may be recreated, so we wait just over 2 scrape intervals
// before creating them.
// If the context is cancelled, we presume the server is shutting down
// and will restart where is was. We do not attempt to write stale markers
// in this case.
if last.IsZero() {
// There never was a scrape, so there will be no stale markers.
return
}
// Wait for when the next scrape would have been, record its timestamp.
var staleTime time.Time
select {
case <-sl.ctx.Done():
return
case <-ticker.C:
staleTime = time.Now()
}
// Wait for when the next scrape would have been, if the target was recreated
// samples should have been ingested by now.
select {
case <-sl.ctx.Done():
return
case <-ticker.C:
}
// Wait for an extra 10% of the interval, just to be safe.
select {
case <-sl.ctx.Done():
return
case <-time.After(interval / 10):
}
// Call sl.append again with an empty scrape to trigger stale markers.
// If the target has since been recreated and scraped, the
// stale markers will be out of order and ignored.
if _, _, err := sl.append([]byte{}, staleTime); err != nil {
sl.l.With("err", err).Error("stale append failed")
}
if err := sl.reportStale(staleTime); err != nil {
sl.l.With("err", err).Error("stale report failed")
}
}
// Stop the scraping. May still write data and stale markers after it has
// returned. Cancel the context to stop all writes.
func (sl *scrapeLoop) stop() {
sl.cancel()
<-sl.stopped
}
type sample struct {
metric labels.Labels
t int64
v float64
}
type samples []sample
func (s samples) Len() int { return len(s) }
func (s samples) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
func (s samples) Less(i, j int) bool {
d := labels.Compare(s[i].metric, s[j].metric)
if d < 0 {
return true
} else if d > 0 {
return false
}
return s[i].t < s[j].t
}
func (sl *scrapeLoop) append(b []byte, ts time.Time) (total, added int, err error) {
var (
app = sl.appender()
p = textparse.New(b)
defTime = timestamp.FromTime(ts)
numOutOfOrder = 0
numDuplicates = 0
numOutOfBounds = 0
)
var sampleLimitErr error
loop:
for p.Next() {
total++
t := defTime
met, tp, v := p.At()
if tp != nil {
t = *tp
}
ref, ok := sl.cache.getRef(yoloString(met))
if ok {
lset := sl.cache.lsets[ref].lset
switch err = app.AddFast(lset, ref, t, v); err {
case nil:
if tp == nil {
e := sl.cache.lsets[ref]
sl.cache.trackStaleness(e.hash, e.lset)
}
case storage.ErrNotFound:
ok = false
case errSeriesDropped:
err = nil
continue
case storage.ErrOutOfOrderSample:
numOutOfOrder++
sl.l.With("timeseries", string(met)).Debug("Out of order sample")
targetScrapeSampleOutOfOrder.Inc()
continue
case storage.ErrDuplicateSampleForTimestamp:
numDuplicates++
sl.l.With("timeseries", string(met)).Debug("Duplicate sample for timestamp")
targetScrapeSampleDuplicate.Inc()
continue
case storage.ErrOutOfBounds:
numOutOfBounds++
sl.l.With("timeseries", string(met)).Debug("Out of bounds metric")
targetScrapeSampleOutOfBounds.Inc()
continue
case errSampleLimit:
// Keep on parsing output if we hit the limit, so we report the correct
// total number of samples scraped.
sampleLimitErr = err
added++
continue
default:
break loop
}
}
if !ok {
var (
lset labels.Labels
mets string
hash uint64
)
if e, ok := sl.cache.lsets[ref]; ok {
mets = e.metric
lset = e.lset
hash = e.hash
} else {
mets = p.Metric(&lset)
hash = lset.Hash()
}
var ref string
ref, err = app.Add(lset, t, v)
// TODO(fabxc): also add a dropped-cache?
switch err {
case nil:
case errSeriesDropped:
err = nil
continue
case storage.ErrOutOfOrderSample:
err = nil
numOutOfOrder++
sl.l.With("timeseries", string(met)).Debug("Out of order sample")
targetScrapeSampleOutOfOrder.Inc()
continue
case storage.ErrDuplicateSampleForTimestamp:
err = nil
numDuplicates++
sl.l.With("timeseries", string(met)).Debug("Duplicate sample for timestamp")
targetScrapeSampleDuplicate.Inc()
continue
case storage.ErrOutOfBounds:
err = nil
numOutOfBounds++
sl.l.With("timeseries", string(met)).Debug("Out of bounds metric")
targetScrapeSampleOutOfBounds.Inc()
continue
case errSampleLimit:
sampleLimitErr = err
added++
continue
default:
break loop
}
if tp == nil {
// Bypass staleness logic if there is an explicit timestamp.
sl.cache.trackStaleness(hash, lset)
}
sl.cache.addRef(mets, ref, lset, hash)
}
added++
}
if err == nil {
err = p.Err()
}
if err == nil && sampleLimitErr != nil {
targetScrapeSampleLimit.Inc()
err = sampleLimitErr
}
if numOutOfOrder > 0 {
sl.l.With("numDropped", numOutOfOrder).Warn("Error on ingesting out-of-order samples")
}
if numDuplicates > 0 {
sl.l.With("numDropped", numDuplicates).Warn("Error on ingesting samples with different value but same timestamp")
}
if numOutOfBounds > 0 {
sl.l.With("numOutOfBounds", numOutOfBounds).Warn("Error on ingesting samples that are too old or are too far into the future")
}
if err == nil {
sl.cache.forEachStale(func(lset labels.Labels) bool {
// Series no longer exposed, mark it stale.
_, err = app.Add(lset, defTime, math.Float64frombits(value.StaleNaN))
switch err {
case errSeriesDropped:
err = nil
case storage.ErrOutOfOrderSample, storage.ErrDuplicateSampleForTimestamp:
// Do not count these in logging, as this is expected if a target
// goes away and comes back again with a new scrape loop.
err = nil
}
return err == nil
})
}
if err != nil {
app.Rollback()
return total, added, err
}
if err := app.Commit(); err != nil {
return total, added, err
}
sl.cache.iterDone()
return total, added, nil
}
func yoloString(b []byte) string {
return *((*string)(unsafe.Pointer(&b)))
}
func (sl *scrapeLoop) report(start time.Time, duration time.Duration, scraped, appended int, err error) error {
sl.scraper.report(start, duration, err)
ts := timestamp.FromTime(start)
var health float64
if err == nil {
health = 1
}
app := sl.reportAppender()
if err := sl.addReportSample(app, scrapeHealthMetricName, ts, health); err != nil {
app.Rollback()
return err
}
if err := sl.addReportSample(app, scrapeDurationMetricName, ts, duration.Seconds()); err != nil {
app.Rollback()
return err
}
if err := sl.addReportSample(app, scrapeSamplesMetricName, ts, float64(scraped)); err != nil {
app.Rollback()
return err
}
if err := sl.addReportSample(app, samplesPostRelabelMetricName, ts, float64(appended)); err != nil {
app.Rollback()
return err
}
return app.Commit()
}
func (sl *scrapeLoop) reportStale(start time.Time) error {
ts := timestamp.FromTime(start)
app := sl.reportAppender()
stale := math.Float64frombits(value.StaleNaN)
if err := sl.addReportSample(app, scrapeHealthMetricName, ts, stale); err != nil {
app.Rollback()
return err
}
if err := sl.addReportSample(app, scrapeDurationMetricName, ts, stale); err != nil {
app.Rollback()
return err
}
if err := sl.addReportSample(app, scrapeSamplesMetricName, ts, stale); err != nil {
app.Rollback()
return err
}
if err := sl.addReportSample(app, samplesPostRelabelMetricName, ts, stale); err != nil {
app.Rollback()
return err
}
return app.Commit()
}
func (sl *scrapeLoop) addReportSample(app storage.Appender, s string, t int64, v float64) error {
// Suffix s with the invalid \xff unicode rune to avoid collisions
// with scraped metrics.
s2 := s + "\xff"
ref, ok := sl.cache.getRef(s2)
if ok {
lset := sl.cache.lsets[ref].lset
err := app.AddFast(lset, ref, t, v)
switch err {
case nil:
return nil
case storage.ErrNotFound:
// Try an Add.
case storage.ErrOutOfOrderSample, storage.ErrDuplicateSampleForTimestamp:
// Do not log here, as this is expected if a target goes away and comes back
// again with a new scrape loop.
return nil
default:
return err
}
}
lset := labels.Labels{
labels.Label{Name: labels.MetricName, Value: s},
}
ref, err := app.Add(lset, t, v)
switch err {
case nil:
sl.cache.addRef(s2, ref, lset, lset.Hash())
return nil
case storage.ErrOutOfOrderSample, storage.ErrDuplicateSampleForTimestamp:
return nil
default:
return err
}
}