mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
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66eb013b54
* lib/promscrape: do not store last scrape response when stale markers are disabled * update changelog
1020 lines
38 KiB
Go
1020 lines
38 KiB
Go
package promscrape
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import (
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"bytes"
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"flag"
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"fmt"
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"io"
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"math"
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"math/bits"
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"strings"
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"sync"
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"time"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/auth"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/bloomfilter"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/cgroup"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/decimal"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/leveledbytebufferpool"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/promauth"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/promrelabel"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/promutils"
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parser "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus/stream"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/proxy"
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"github.com/VictoriaMetrics/VictoriaMetrics/lib/timerpool"
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"github.com/VictoriaMetrics/metrics"
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"github.com/cespare/xxhash/v2"
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)
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var (
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suppressScrapeErrors = flag.Bool("promscrape.suppressScrapeErrors", false, "Whether to suppress scrape errors logging. "+
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"The last error for each target is always available at '/targets' page even if scrape errors logging is suppressed. "+
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"See also -promscrape.suppressScrapeErrorsDelay")
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suppressScrapeErrorsDelay = flag.Duration("promscrape.suppressScrapeErrorsDelay", 0, "The delay for suppressing repeated scrape errors logging per each scrape targets. "+
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"This may be used for reducing the number of log lines related to scrape errors. See also -promscrape.suppressScrapeErrors")
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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")
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)
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// ScrapeWork represents a unit of work for scraping Prometheus metrics.
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//
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// It must be immutable during its lifetime, since it is read from concurrently running goroutines.
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type ScrapeWork struct {
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// Full URL (including query args) for the scrape.
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ScrapeURL string
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// Interval for scraping the ScrapeURL.
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ScrapeInterval time.Duration
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// Timeout for scraping the ScrapeURL.
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ScrapeTimeout time.Duration
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// How to deal with conflicting labels.
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// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config
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HonorLabels bool
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// How to deal with scraped timestamps.
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// See https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config
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HonorTimestamps bool
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// Whether to deny redirects during requests to scrape config.
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DenyRedirects bool
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// Do not support enable_http2 option because of the following reasons:
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//
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// - http2 is used very rarely comparing to http for Prometheus metrics exposition and service discovery
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// - http2 is much harder to debug than http
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// - http2 has very bad security record because of its complexity - see https://portswigger.net/research/http2
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//
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// VictoriaMetrics components are compiled with nethttpomithttp2 tag because of these issues.
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//
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// EnableHTTP2 bool
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// OriginalLabels contains original labels before relabeling.
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//
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// These labels are needed for relabeling troubleshooting at /targets page.
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//
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// OriginalLabels are sorted by name.
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OriginalLabels *promutils.Labels
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// Labels to add to the scraped metrics.
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//
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// The list contains at least the following labels according to https://www.robustperception.io/life-of-a-label/
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//
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// * job
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// * instance
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// * user-defined labels set via `relabel_configs` section in `scrape_config`
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//
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// See also https://prometheus.io/docs/concepts/jobs_instances/
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//
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// Labels are sorted by name.
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Labels *promutils.Labels
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// ExternalLabels contains labels from global->external_labels section of -promscrape.config
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//
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// These labels are added to scraped metrics after the relabeling.
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// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3137
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//
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// ExternalLabels are sorted by name.
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ExternalLabels *promutils.Labels
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// ProxyURL HTTP proxy url
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ProxyURL *proxy.URL
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// Auth config for ProxyUR:
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ProxyAuthConfig *promauth.Config
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// Auth config
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AuthConfig *promauth.Config
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// Optional `relabel_configs`.
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RelabelConfigs *promrelabel.ParsedConfigs
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// Optional `metric_relabel_configs`.
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MetricRelabelConfigs *promrelabel.ParsedConfigs
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// The maximum number of metrics to scrape after relabeling.
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SampleLimit int
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// Whether to disable response compression when querying ScrapeURL.
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DisableCompression bool
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// Whether to disable HTTP keep-alive when querying ScrapeURL.
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DisableKeepAlive bool
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// Whether to parse target responses in a streaming manner.
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StreamParse bool
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// The interval for aligning the first scrape.
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ScrapeAlignInterval time.Duration
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// The offset for the first scrape.
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ScrapeOffset time.Duration
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// Optional limit on the number of unique series the scrape target can expose.
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SeriesLimit int
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// Whether to process stale markers for the given target.
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// See https://docs.victoriametrics.com/vmagent.html#prometheus-staleness-markers
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NoStaleMarkers bool
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// The Tenant Info
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AuthToken *auth.Token
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// The original 'job_name'
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jobNameOriginal string
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}
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func (sw *ScrapeWork) canSwitchToStreamParseMode() bool {
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// Deny switching to stream parse mode if `sample_limit` or `series_limit` options are set,
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// since these limits cannot be applied in stream parsing mode.
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return sw.SampleLimit <= 0 && sw.SeriesLimit <= 0
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}
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// key returns unique identifier for the given sw.
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//
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// It can be used for comparing for equality for two ScrapeWork objects.
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func (sw *ScrapeWork) key() string {
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// Do not take into account OriginalLabels, since they can be changed with relabeling.
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// Do not take into account RelabelConfigs, since it is already applied to Labels.
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// Take into account JobNameOriginal in order to capture the case when the original job_name is changed via relabeling.
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key := fmt.Sprintf("JobNameOriginal=%s, ScrapeURL=%s, ScrapeInterval=%s, ScrapeTimeout=%s, HonorLabels=%v, HonorTimestamps=%v, DenyRedirects=%v, Labels=%s, "+
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"ExternalLabels=%s, "+
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"ProxyURL=%s, ProxyAuthConfig=%s, AuthConfig=%s, MetricRelabelConfigs=%q, "+
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"SampleLimit=%d, DisableCompression=%v, DisableKeepAlive=%v, StreamParse=%v, "+
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"ScrapeAlignInterval=%s, ScrapeOffset=%s, SeriesLimit=%d, NoStaleMarkers=%v",
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sw.jobNameOriginal, sw.ScrapeURL, sw.ScrapeInterval, sw.ScrapeTimeout, sw.HonorLabels, sw.HonorTimestamps, sw.DenyRedirects, sw.Labels.String(),
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sw.ExternalLabels.String(),
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sw.ProxyURL.String(), sw.ProxyAuthConfig.String(), sw.AuthConfig.String(), sw.MetricRelabelConfigs.String(),
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sw.SampleLimit, sw.DisableCompression, sw.DisableKeepAlive, sw.StreamParse,
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sw.ScrapeAlignInterval, sw.ScrapeOffset, sw.SeriesLimit, sw.NoStaleMarkers)
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return key
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}
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// Job returns job for the ScrapeWork
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func (sw *ScrapeWork) Job() string {
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return sw.Labels.Get("job")
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}
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type scrapeWork struct {
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// Config for the scrape.
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Config *ScrapeWork
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// ReadData is called for reading the data.
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ReadData func(dst []byte) ([]byte, error)
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// GetStreamReader is called if Config.StreamParse is set.
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GetStreamReader func() (*streamReader, error)
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// PushData is called for pushing collected data.
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PushData func(at *auth.Token, wr *prompbmarshal.WriteRequest)
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// ScrapeGroup is name of ScrapeGroup that
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// scrapeWork belongs to
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ScrapeGroup string
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tmpRow parser.Row
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// This flag is set to true if series_limit is exceeded.
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seriesLimitExceeded bool
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// labelsHashBuf is used for calculating the hash on series labels
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labelsHashBuf []byte
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// Optional limiter on the number of unique series per scrape target.
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seriesLimiter *bloomfilter.Limiter
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// prevBodyLen contains the previous response body length for the given scrape work.
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// It is used as a hint in order to reduce memory usage for body buffers.
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prevBodyLen int
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// prevLabelsLen contains the number labels scraped during the previous scrape.
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// It is used as a hint in order to reduce memory usage when parsing scrape responses.
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prevLabelsLen int
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// lastScrape holds the last response from scrape target.
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// It is used for staleness tracking and for populating scrape_series_added metric.
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// The lastScrape isn't populated if -promscrape.noStaleMarkers is set. This reduces memory usage.
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lastScrape []byte
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// lastScrapeCompressed is used for storing the compressed lastScrape between scrapes
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// in stream parsing mode in order to reduce memory usage when the lastScrape size
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// equals to or exceeds -promscrape.minResponseSizeForStreamParse
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lastScrapeCompressed []byte
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// nextErrorLogTime is the timestamp in millisecond when the next scrape error should be logged.
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nextErrorLogTime int64
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// failureRequestsCount is the number of suppressed scrape errors during the last suppressScrapeErrorsDelay
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failureRequestsCount int
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// successRequestsCount is the number of success requests during the last suppressScrapeErrorsDelay
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successRequestsCount int
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}
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func (sw *scrapeWork) loadLastScrape() string {
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if len(sw.lastScrapeCompressed) > 0 {
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b, err := encoding.DecompressZSTD(sw.lastScrape[:0], sw.lastScrapeCompressed)
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if err != nil {
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logger.Panicf("BUG: cannot unpack compressed previous response: %s", err)
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}
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sw.lastScrape = b
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}
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return bytesutil.ToUnsafeString(sw.lastScrape)
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}
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func (sw *scrapeWork) storeLastScrape(lastScrape []byte) {
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mustCompress := minResponseSizeForStreamParse.N > 0 && len(lastScrape) >= minResponseSizeForStreamParse.IntN()
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if mustCompress {
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sw.lastScrapeCompressed = encoding.CompressZSTDLevel(sw.lastScrapeCompressed[:0], lastScrape, 1)
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sw.lastScrape = nil
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} else {
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sw.lastScrape = append(sw.lastScrape[:0], lastScrape...)
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sw.lastScrapeCompressed = nil
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}
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}
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func (sw *scrapeWork) finalizeLastScrape() {
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if len(sw.lastScrapeCompressed) > 0 {
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// The compressed lastScrape is available in sw.lastScrapeCompressed.
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// Release the memory occupied by sw.lastScrape, so it won't be occupied between scrapes.
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sw.lastScrape = nil
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}
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if len(sw.lastScrape) > 0 {
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// Release the memory occupied by sw.lastScrapeCompressed, so it won't be occupied between scrapes.
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sw.lastScrapeCompressed = nil
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}
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}
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func (sw *scrapeWork) run(stopCh <-chan struct{}, globalStopCh <-chan struct{}) {
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var randSleep uint64
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scrapeInterval := sw.Config.ScrapeInterval
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scrapeAlignInterval := sw.Config.ScrapeAlignInterval
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scrapeOffset := sw.Config.ScrapeOffset
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if scrapeOffset > 0 {
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scrapeAlignInterval = scrapeInterval
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}
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if scrapeAlignInterval <= 0 {
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// Calculate start time for the first scrape from ScrapeURL and labels.
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// This should spread load when scraping many targets with different
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// scrape urls and labels.
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// This also makes consistent scrape times across restarts
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// for a target with the same ScrapeURL and labels.
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//
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// Include clusterName to the key in order to guarantee that the same
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// scrape target is scraped at different offsets per each cluster.
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// This guarantees that the deduplication consistently leaves samples received from the same vmagent.
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// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2679
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//
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// Include clusterMemberID to the key in order to guarantee that each member in vmagent cluster
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// scrapes replicated targets at different time offsets. This guarantees that the deduplication consistently leaves samples
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// received from the same vmagent replica.
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// See https://docs.victoriametrics.com/vmagent.html#scraping-big-number-of-targets
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key := fmt.Sprintf("clusterName=%s, clusterMemberID=%d, ScrapeURL=%s, Labels=%s", *clusterName, clusterMemberID, sw.Config.ScrapeURL, sw.Config.Labels.String())
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h := xxhash.Sum64(bytesutil.ToUnsafeBytes(key))
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randSleep = uint64(float64(scrapeInterval) * (float64(h) / (1 << 64)))
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sleepOffset := uint64(time.Now().UnixNano()) % uint64(scrapeInterval)
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if randSleep < sleepOffset {
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randSleep += uint64(scrapeInterval)
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}
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randSleep -= sleepOffset
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} else {
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d := uint64(scrapeAlignInterval)
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randSleep = d - uint64(time.Now().UnixNano())%d
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if scrapeOffset > 0 {
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randSleep += uint64(scrapeOffset)
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}
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randSleep %= uint64(scrapeInterval)
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}
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timer := timerpool.Get(time.Duration(randSleep))
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var timestamp int64
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var ticker *time.Ticker
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select {
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case <-stopCh:
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timerpool.Put(timer)
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return
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case <-timer.C:
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timerpool.Put(timer)
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ticker = time.NewTicker(scrapeInterval)
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timestamp = time.Now().UnixNano() / 1e6
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sw.scrapeAndLogError(timestamp, timestamp)
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}
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defer ticker.Stop()
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for {
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timestamp += scrapeInterval.Milliseconds()
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select {
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case <-stopCh:
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t := time.Now().UnixNano() / 1e6
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lastScrape := sw.loadLastScrape()
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select {
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case <-globalStopCh:
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// Do not send staleness markers on graceful shutdown as Prometheus does.
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// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2013#issuecomment-1006994079
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default:
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if !sw.Config.NoStaleMarkers {
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// Send staleness markers to all the metrics scraped last time from the target
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// when the given target disappears as Prometheus does.
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// Use the current real timestamp for staleness markers, so queries
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// stop returning data just after the time the target disappears.
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sw.sendStaleSeries(lastScrape, "", t, true)
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}
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}
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if sw.seriesLimiter != nil {
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sw.seriesLimiter.MustStop()
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sw.seriesLimiter = nil
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}
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return
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case tt := <-ticker.C:
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t := tt.UnixNano() / 1e6
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if d := math.Abs(float64(t - timestamp)); d > 0 && d/float64(scrapeInterval.Milliseconds()) > 0.1 {
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// Too big jitter. Adjust timestamp
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timestamp = t
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}
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sw.scrapeAndLogError(timestamp, t)
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}
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}
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}
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func (sw *scrapeWork) logError(s string) {
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if !*suppressScrapeErrors {
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logger.ErrorfSkipframes(1, "error when scraping %q from job %q with labels %s: %s; "+
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"scrape errors can be disabled by -promscrape.suppressScrapeErrors command-line flag",
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sw.Config.ScrapeURL, sw.Config.Job(), sw.Config.Labels.String(), s)
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}
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}
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func (sw *scrapeWork) scrapeAndLogError(scrapeTimestamp, realTimestamp int64) {
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err := sw.scrapeInternal(scrapeTimestamp, realTimestamp)
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if *suppressScrapeErrors {
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return
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}
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if err == nil {
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sw.successRequestsCount++
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return
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}
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sw.failureRequestsCount++
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if sw.nextErrorLogTime == 0 {
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sw.nextErrorLogTime = realTimestamp + suppressScrapeErrorsDelay.Milliseconds()
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}
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if realTimestamp < sw.nextErrorLogTime {
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return
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}
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totalRequests := sw.failureRequestsCount + sw.successRequestsCount
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logger.Warnf("cannot scrape target %q (%s) %d out of %d times during -promscrape.suppressScrapeErrorsDelay=%s; the last error: %s",
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sw.Config.ScrapeURL, sw.Config.Labels.String(), sw.failureRequestsCount, totalRequests, *suppressScrapeErrorsDelay, err)
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sw.nextErrorLogTime = realTimestamp + suppressScrapeErrorsDelay.Milliseconds()
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sw.failureRequestsCount = 0
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sw.successRequestsCount = 0
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}
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var (
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scrapeDuration = metrics.NewHistogram("vm_promscrape_scrape_duration_seconds")
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scrapeResponseSize = metrics.NewHistogram("vm_promscrape_scrape_response_size_bytes")
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scrapedSamples = metrics.NewHistogram("vm_promscrape_scraped_samples")
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scrapesSkippedBySampleLimit = metrics.NewCounter("vm_promscrape_scrapes_skipped_by_sample_limit_total")
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scrapesFailed = metrics.NewCounter("vm_promscrape_scrapes_failed_total")
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pushDataDuration = metrics.NewHistogram("vm_promscrape_push_data_duration_seconds")
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)
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func (sw *scrapeWork) mustSwitchToStreamParseMode(responseSize int) bool {
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if minResponseSizeForStreamParse.N <= 0 {
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return false
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}
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return sw.Config.canSwitchToStreamParseMode() && responseSize >= minResponseSizeForStreamParse.IntN()
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}
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// getTargetResponse() fetches response from sw target in the same way as when scraping the target.
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func (sw *scrapeWork) getTargetResponse() ([]byte, error) {
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// use stream reader when stream mode enabled
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if *streamParse || sw.Config.StreamParse || sw.mustSwitchToStreamParseMode(sw.prevBodyLen) {
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// Read the response in stream mode.
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sr, err := sw.GetStreamReader()
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if err != nil {
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return nil, err
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}
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data, err := io.ReadAll(sr)
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sr.MustClose()
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return data, err
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}
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// Read the response in usual mode.
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return sw.ReadData(nil)
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}
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func (sw *scrapeWork) scrapeInternal(scrapeTimestamp, realTimestamp int64) error {
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if *streamParse || sw.Config.StreamParse || sw.mustSwitchToStreamParseMode(sw.prevBodyLen) {
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// Read data from scrape targets in streaming manner.
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// This case is optimized for targets exposing more than ten thousand of metrics per target.
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return sw.scrapeStream(scrapeTimestamp, realTimestamp)
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}
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// Common case: read all the data from scrape target to memory (body) and then process it.
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// This case should work more optimally than stream parse code for common case when scrape target exposes
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// up to a few thousand metrics.
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body := leveledbytebufferpool.Get(sw.prevBodyLen)
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var err error
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body.B, err = sw.ReadData(body.B[:0])
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releaseBody, err := sw.processScrapedData(scrapeTimestamp, realTimestamp, body, err)
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if releaseBody {
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leveledbytebufferpool.Put(body)
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}
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return err
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}
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var processScrapedDataConcurrencyLimitCh = make(chan struct{}, cgroup.AvailableCPUs())
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func (sw *scrapeWork) processScrapedData(scrapeTimestamp, realTimestamp int64, body *bytesutil.ByteBuffer, err error) (bool, error) {
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// This function is CPU-bound, while it may allocate big amounts of memory.
|
|
// That's why it is a good idea to limit the number of concurrent calls to this function
|
|
// in order to limit memory usage under high load without sacrificing the performance.
|
|
processScrapedDataConcurrencyLimitCh <- struct{}{}
|
|
defer func() {
|
|
<-processScrapedDataConcurrencyLimitCh
|
|
}()
|
|
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)
|
|
lastScrape := sw.loadLastScrape()
|
|
bodyString := bytesutil.ToUnsafeString(body.B)
|
|
areIdenticalSeries := sw.areIdenticalSeries(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
|
|
// cannot track the number of new time series when stale markers are disabled.
|
|
if !sw.Config.NoStaleMarkers && !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(lastScrape, bodyString)
|
|
}
|
|
samplesDropped := 0
|
|
if sw.seriesLimitExceeded || !areIdenticalSeries {
|
|
samplesDropped = sw.applySeriesLimit(wc)
|
|
}
|
|
am := &autoMetrics{
|
|
up: up,
|
|
scrapeDurationSeconds: duration,
|
|
samplesScraped: samplesScraped,
|
|
samplesPostRelabeling: samplesPostRelabeling,
|
|
seriesAdded: seriesAdded,
|
|
seriesLimitSamplesDropped: samplesDropped,
|
|
}
|
|
sw.addAutoMetrics(am, wc, scrapeTimestamp)
|
|
sw.pushData(sw.Config.AuthToken, &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 !sw.Config.NoStaleMarkers && !areIdenticalSeries {
|
|
// Send stale markers for disappeared metrics with the real scrape timestamp
|
|
// in order to guarantee that query doesn't return data after this time for the disappeared metrics.
|
|
sw.sendStaleSeries(lastScrape, bodyString, realTimestamp, false)
|
|
sw.storeLastScrape(body.B)
|
|
}
|
|
sw.finalizeLastScrape()
|
|
tsmGlobal.Update(sw, up == 1, realTimestamp, int64(duration*1000), samplesScraped, err)
|
|
return !mustSwitchToStreamParse, err
|
|
}
|
|
|
|
func (sw *scrapeWork) pushData(at *auth.Token, wr *prompbmarshal.WriteRequest) {
|
|
startTime := time.Now()
|
|
sw.PushData(at, wr)
|
|
pushDataDuration.UpdateDuration(startTime)
|
|
}
|
|
|
|
type streamBodyReader struct {
|
|
body []byte
|
|
bodyLen int
|
|
readOffset int
|
|
}
|
|
|
|
func (sbr *streamBodyReader) Init(sr *streamReader) error {
|
|
sbr.body = nil
|
|
sbr.bodyLen = 0
|
|
sbr.readOffset = 0
|
|
// Read the whole response body in memory before parsing it in stream mode.
|
|
// This minimizes the time needed for reading response body from scrape target.
|
|
startTime := fasttime.UnixTimestamp()
|
|
body, err := io.ReadAll(sr)
|
|
if err != nil {
|
|
d := fasttime.UnixTimestamp() - startTime
|
|
return fmt.Errorf("cannot read stream body in %d seconds: %w", d, err)
|
|
}
|
|
sbr.body = body
|
|
sbr.bodyLen = len(body)
|
|
return nil
|
|
}
|
|
|
|
func (sbr *streamBodyReader) Read(b []byte) (int, error) {
|
|
if sbr.readOffset >= len(sbr.body) {
|
|
return 0, io.EOF
|
|
}
|
|
n := copy(b, sbr.body[sbr.readOffset:])
|
|
sbr.readOffset += n
|
|
return n, nil
|
|
}
|
|
|
|
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.
|
|
var sbr streamBodyReader
|
|
|
|
lastScrape := sw.loadLastScrape()
|
|
bodyString := ""
|
|
areIdenticalSeries := true
|
|
samplesDropped := 0
|
|
sr, err := sw.GetStreamReader()
|
|
if err != nil {
|
|
err = fmt.Errorf("cannot read data: %w", err)
|
|
} else {
|
|
var mu sync.Mutex
|
|
err = sbr.Init(sr)
|
|
if err == nil {
|
|
bodyString = bytesutil.ToUnsafeString(sbr.body)
|
|
areIdenticalSeries = sw.areIdenticalSeries(lastScrape, bodyString)
|
|
err = stream.Parse(&sbr, scrapeTimestamp, false, 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)
|
|
}
|
|
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)
|
|
}
|
|
if sw.seriesLimitExceeded || !areIdenticalSeries {
|
|
samplesDropped += sw.applySeriesLimit(wc)
|
|
}
|
|
// 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
|
|
sw.pushData(sw.Config.AuthToken, &wc.writeRequest)
|
|
wc.resetNoRows()
|
|
return nil
|
|
}, sw.logError)
|
|
}
|
|
sr.MustClose()
|
|
}
|
|
|
|
scrapedSamples.Update(float64(samplesScraped))
|
|
endTimestamp := time.Now().UnixNano() / 1e6
|
|
duration := float64(endTimestamp-realTimestamp) / 1e3
|
|
scrapeDuration.Update(duration)
|
|
scrapeResponseSize.Update(float64(sbr.bodyLen))
|
|
up := 1
|
|
if err != nil {
|
|
// Mark the scrape as failed even if it already read and pushed some samples
|
|
// to remote storage. This makes the logic compatible with Prometheus.
|
|
up = 0
|
|
scrapesFailed.Inc()
|
|
}
|
|
seriesAdded := 0
|
|
// cannot track the number of new time series when stale markers are disabled.
|
|
if !sw.Config.NoStaleMarkers && !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(lastScrape, bodyString)
|
|
}
|
|
am := &autoMetrics{
|
|
up: up,
|
|
scrapeDurationSeconds: duration,
|
|
samplesScraped: samplesScraped,
|
|
samplesPostRelabeling: samplesPostRelabeling,
|
|
seriesAdded: seriesAdded,
|
|
seriesLimitSamplesDropped: samplesDropped,
|
|
}
|
|
sw.addAutoMetrics(am, wc, scrapeTimestamp)
|
|
sw.pushData(sw.Config.AuthToken, &wc.writeRequest)
|
|
sw.prevLabelsLen = len(wc.labels)
|
|
sw.prevBodyLen = sbr.bodyLen
|
|
wc.reset()
|
|
writeRequestCtxPool.Put(wc)
|
|
if !sw.Config.NoStaleMarkers && !areIdenticalSeries {
|
|
// Send stale markers for disappeared metrics with the real scrape timestamp
|
|
// in order to guarantee that query doesn't return data after this time for the disappeared metrics.
|
|
sw.sendStaleSeries(lastScrape, bodyString, realTimestamp, false)
|
|
sw.storeLastScrape(sbr.body)
|
|
}
|
|
sw.finalizeLastScrape()
|
|
tsmGlobal.Update(sw, 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
|
|
}
|
|
|
|
func (sw *scrapeWork) areIdenticalSeries(prevData, currData string) bool {
|
|
if sw.Config.NoStaleMarkers && sw.Config.SeriesLimit <= 0 {
|
|
// Do not spend CPU time on tracking the changes in series if stale markers are disabled.
|
|
// The check for series_limit is needed for https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3660
|
|
return true
|
|
}
|
|
return parser.AreIdenticalSeriesFast(prevData, currData)
|
|
}
|
|
|
|
// 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() {
|
|
wc.writeRequest.Reset()
|
|
|
|
labels := wc.labels
|
|
for i := range labels {
|
|
label := &labels[i]
|
|
label.Name = ""
|
|
label.Value = ""
|
|
}
|
|
wc.labels = wc.labels[:0]
|
|
|
|
wc.samples = wc.samples[:0]
|
|
}
|
|
|
|
var writeRequestCtxPool leveledWriteRequestCtxPool
|
|
|
|
func (sw *scrapeWork) getSeriesAdded(lastScrape, currScrape string) int {
|
|
if currScrape == "" {
|
|
return 0
|
|
}
|
|
bodyString := parser.GetRowsDiff(currScrape, lastScrape)
|
|
return strings.Count(bodyString, "\n")
|
|
}
|
|
|
|
func (sw *scrapeWork) applySeriesLimit(wc *writeRequestCtx) int {
|
|
if sw.Config.SeriesLimit <= 0 {
|
|
return 0
|
|
}
|
|
if sw.seriesLimiter == nil {
|
|
sw.seriesLimiter = bloomfilter.NewLimiter(sw.Config.SeriesLimit, 24*time.Hour)
|
|
}
|
|
sl := sw.seriesLimiter
|
|
dstSeries := wc.writeRequest.Timeseries[:0]
|
|
samplesDropped := 0
|
|
for _, ts := range wc.writeRequest.Timeseries {
|
|
h := sw.getLabelsHash(ts.Labels)
|
|
if !sl.Add(h) {
|
|
samplesDropped++
|
|
continue
|
|
}
|
|
dstSeries = append(dstSeries, ts)
|
|
}
|
|
prompbmarshal.ResetTimeSeries(wc.writeRequest.Timeseries[len(dstSeries):])
|
|
wc.writeRequest.Timeseries = dstSeries
|
|
if samplesDropped > 0 && !sw.seriesLimitExceeded {
|
|
sw.seriesLimitExceeded = true
|
|
}
|
|
return samplesDropped
|
|
}
|
|
|
|
var sendStaleSeriesConcurrencyLimitCh = make(chan struct{}, cgroup.AvailableCPUs())
|
|
|
|
func (sw *scrapeWork) sendStaleSeries(lastScrape, currScrape string, timestamp int64, addAutoSeries bool) {
|
|
// This function is CPU-bound, while it may allocate big amounts of memory.
|
|
// That's why it is a good idea to limit the number of concurrent calls to this function
|
|
// in order to limit memory usage under high load without sacrificing the performance.
|
|
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3668
|
|
sendStaleSeriesConcurrencyLimitCh <- struct{}{}
|
|
defer func() {
|
|
<-sendStaleSeriesConcurrencyLimitCh
|
|
}()
|
|
bodyString := lastScrape
|
|
if currScrape != "" {
|
|
bodyString = parser.GetRowsDiff(lastScrape, currScrape)
|
|
}
|
|
wc := writeRequestCtxPool.Get(sw.prevLabelsLen)
|
|
defer func() {
|
|
wc.reset()
|
|
writeRequestCtxPool.Put(wc)
|
|
}()
|
|
if bodyString != "" {
|
|
// Send stale markers in streaming mode in order to reduce memory usage
|
|
// when stale markers for targets exposing big number of metrics must be generated.
|
|
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3668
|
|
// and https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3675
|
|
var mu sync.Mutex
|
|
br := bytes.NewBufferString(bodyString)
|
|
err := stream.Parse(br, timestamp, false, false, func(rows []parser.Row) error {
|
|
mu.Lock()
|
|
defer mu.Unlock()
|
|
for i := range rows {
|
|
sw.addRowToTimeseries(wc, &rows[i], timestamp, true)
|
|
}
|
|
// Apply series limit to stale markers in order to prevent sending stale markers for newly created series.
|
|
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3660
|
|
if sw.seriesLimitExceeded {
|
|
sw.applySeriesLimit(wc)
|
|
}
|
|
// 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
|
|
setStaleMarkersForRows(wc.writeRequest.Timeseries)
|
|
sw.pushData(sw.Config.AuthToken, &wc.writeRequest)
|
|
wc.resetNoRows()
|
|
return nil
|
|
}, sw.logError)
|
|
if err != nil {
|
|
sw.logError(fmt.Errorf("cannot send stale markers: %w", err).Error())
|
|
}
|
|
}
|
|
if addAutoSeries {
|
|
am := &autoMetrics{}
|
|
sw.addAutoMetrics(am, wc, timestamp)
|
|
}
|
|
setStaleMarkersForRows(wc.writeRequest.Timeseries)
|
|
sw.pushData(sw.Config.AuthToken, &wc.writeRequest)
|
|
}
|
|
|
|
func setStaleMarkersForRows(series []prompbmarshal.TimeSeries) {
|
|
for _, tss := range series {
|
|
samples := tss.Samples
|
|
for i := range samples {
|
|
samples[i].Value = decimal.StaleNaN
|
|
}
|
|
staleSamplesCreated.Add(len(samples))
|
|
}
|
|
}
|
|
|
|
var staleSamplesCreated = metrics.NewCounter(`vm_promscrape_stale_samples_created_total`)
|
|
|
|
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)
|
|
}
|
|
|
|
type autoMetrics struct {
|
|
up int
|
|
scrapeDurationSeconds float64
|
|
samplesScraped int
|
|
samplesPostRelabeling int
|
|
seriesAdded int
|
|
seriesLimitSamplesDropped int
|
|
}
|
|
|
|
func isAutoMetric(s string) bool {
|
|
switch s {
|
|
case "up", "scrape_duration_seconds", "scrape_samples_scraped",
|
|
"scrape_samples_post_metric_relabeling", "scrape_series_added",
|
|
"scrape_timeout_seconds", "scrape_samples_limit",
|
|
"scrape_series_limit_samples_dropped", "scrape_series_limit",
|
|
"scrape_series_current":
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (sw *scrapeWork) addAutoMetrics(am *autoMetrics, wc *writeRequestCtx, timestamp int64) {
|
|
sw.addAutoTimeseries(wc, "up", float64(am.up), timestamp)
|
|
sw.addAutoTimeseries(wc, "scrape_duration_seconds", am.scrapeDurationSeconds, timestamp)
|
|
sw.addAutoTimeseries(wc, "scrape_samples_scraped", float64(am.samplesScraped), timestamp)
|
|
sw.addAutoTimeseries(wc, "scrape_samples_post_metric_relabeling", float64(am.samplesPostRelabeling), timestamp)
|
|
sw.addAutoTimeseries(wc, "scrape_series_added", float64(am.seriesAdded), timestamp)
|
|
sw.addAutoTimeseries(wc, "scrape_timeout_seconds", sw.Config.ScrapeTimeout.Seconds(), timestamp)
|
|
if sampleLimit := sw.Config.SampleLimit; sampleLimit > 0 {
|
|
// Expose scrape_samples_limit metric if sample_limit config is set for the target.
|
|
// See https://github.com/VictoriaMetrics/operator/issues/497
|
|
sw.addAutoTimeseries(wc, "scrape_samples_limit", float64(sampleLimit), timestamp)
|
|
}
|
|
if sl := sw.seriesLimiter; sl != nil {
|
|
sw.addAutoTimeseries(wc, "scrape_series_limit_samples_dropped", float64(am.seriesLimitSamplesDropped), timestamp)
|
|
sw.addAutoTimeseries(wc, "scrape_series_limit", float64(sl.MaxItems()), timestamp)
|
|
sw.addAutoTimeseries(wc, "scrape_series_current", float64(sl.CurrentItems()), timestamp)
|
|
}
|
|
}
|
|
|
|
// 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) {
|
|
metric := r.Metric
|
|
|
|
// Add `exported_` prefix to metrics, which clash with the automatically generated
|
|
// metric names only if the following conditions are met:
|
|
//
|
|
// - The `honor_labels` option isn't set to true in the scrape_config.
|
|
// If `honor_labels: true`, then the scraped metric name must remain unchanged
|
|
// because the user explicitly asked about it in the config.
|
|
// - The metric has no labels (tags). If it has labels, then the metric value
|
|
// will be written into a separate time series comparing to automatically generated time series.
|
|
//
|
|
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3557
|
|
// and https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3406
|
|
if needRelabel && !sw.Config.HonorLabels && len(r.Tags) == 0 && isAutoMetric(metric) {
|
|
bb := bbPool.Get()
|
|
bb.B = append(bb.B, "exported_"...)
|
|
bb.B = append(bb.B, metric...)
|
|
metric = bytesutil.InternBytes(bb.B)
|
|
bbPool.Put(bb)
|
|
}
|
|
labelsLen := len(wc.labels)
|
|
targetLabels := sw.Config.Labels.GetLabels()
|
|
wc.labels = appendLabels(wc.labels, metric, r.Tags, targetLabels, sw.Config.HonorLabels)
|
|
if needRelabel {
|
|
wc.labels = sw.Config.MetricRelabelConfigs.Apply(wc.labels, labelsLen)
|
|
}
|
|
wc.labels = promrelabel.FinalizeLabels(wc.labels[:labelsLen], wc.labels[labelsLen:])
|
|
if len(wc.labels) == labelsLen {
|
|
// Skip row without labels.
|
|
return
|
|
}
|
|
// Add labels from `global->external_labels` section after the relabeling like Prometheus does.
|
|
// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/3137
|
|
externalLabels := sw.Config.ExternalLabels.GetLabels()
|
|
wc.labels = appendExtraLabels(wc.labels, externalLabels, labelsLen, sw.Config.HonorLabels)
|
|
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:],
|
|
})
|
|
}
|
|
|
|
var bbPool bytesutil.ByteBufferPool
|
|
|
|
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,
|
|
})
|
|
}
|
|
return appendExtraLabels(dst, extraLabels, dstLen, honorLabels)
|
|
}
|
|
|
|
func appendExtraLabels(dst, extraLabels []prompbmarshal.Label, offset int, honorLabels bool) []prompbmarshal.Label {
|
|
// Add extraLabels to labels.
|
|
// Handle duplicates in the same way as Prometheus does.
|
|
if len(dst) == offset {
|
|
// Fast path - add extraLabels to dst without the need to de-duplicate.
|
|
dst = append(dst, extraLabels...)
|
|
return dst
|
|
}
|
|
offsetEnd := len(dst)
|
|
for _, label := range extraLabels {
|
|
labels := dst[offset:offsetEnd]
|
|
prevLabel := promrelabel.GetLabelByName(labels, label.Name)
|
|
if prevLabel == nil {
|
|
// Fast path - the label doesn't exist in labels, so just add it to dst.
|
|
dst = append(dst, 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
|
|
exportedLabel := promrelabel.GetLabelByName(labels, exportedName)
|
|
if exportedLabel != nil {
|
|
// The label with the name exported_<label.Name> already exists.
|
|
// Add yet another 'exported_' prefix to it.
|
|
exportedLabel.Name = "exported_" + exportedName
|
|
}
|
|
prevLabel.Name = exportedName
|
|
dst = append(dst, label)
|
|
}
|
|
return dst
|
|
}
|