prometheus/storage/remote/write.go
Ganesh Vernekar a1087ed37a
Fix scraping of sparse histograms (#9031)
Signed-off-by: Ganesh Vernekar <ganeshvern@gmail.com>
2021-07-01 18:19:04 +05:30

263 lines
7.3 KiB
Go

// Copyright 2017 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 remote
import (
"context"
"fmt"
"sync"
"time"
"github.com/go-kit/log"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/pkg/exemplar"
"github.com/prometheus/prometheus/pkg/histogram"
"github.com/prometheus/prometheus/pkg/labels"
"github.com/prometheus/prometheus/storage"
"github.com/prometheus/prometheus/tsdb/wal"
)
var (
samplesIn = promauto.NewCounter(prometheus.CounterOpts{
Namespace: namespace,
Subsystem: subsystem,
Name: "samples_in_total",
Help: "Samples in to remote storage, compare to samples out for queue managers.",
})
exemplarsIn = promauto.NewCounter(prometheus.CounterOpts{
Namespace: namespace,
Subsystem: subsystem,
Name: "exemplars_in_total",
Help: "Exemplars in to remote storage, compare to exemplars out for queue managers.",
})
)
// WriteStorage represents all the remote write storage.
type WriteStorage struct {
logger log.Logger
reg prometheus.Registerer
mtx sync.Mutex
watcherMetrics *wal.WatcherMetrics
liveReaderMetrics *wal.LiveReaderMetrics
externalLabels labels.Labels
walDir string
queues map[string]*QueueManager
samplesIn *ewmaRate
flushDeadline time.Duration
interner *pool
scraper ReadyScrapeManager
// For timestampTracker.
highestTimestamp *maxTimestamp
}
// NewWriteStorage creates and runs a WriteStorage.
func NewWriteStorage(logger log.Logger, reg prometheus.Registerer, walDir string, flushDeadline time.Duration, sm ReadyScrapeManager) *WriteStorage {
if logger == nil {
logger = log.NewNopLogger()
}
rws := &WriteStorage{
queues: make(map[string]*QueueManager),
watcherMetrics: wal.NewWatcherMetrics(reg),
liveReaderMetrics: wal.NewLiveReaderMetrics(reg),
logger: logger,
reg: reg,
flushDeadline: flushDeadline,
samplesIn: newEWMARate(ewmaWeight, shardUpdateDuration),
walDir: walDir,
interner: newPool(),
scraper: sm,
highestTimestamp: &maxTimestamp{
Gauge: prometheus.NewGauge(prometheus.GaugeOpts{
Namespace: namespace,
Subsystem: subsystem,
Name: "highest_timestamp_in_seconds",
Help: "Highest timestamp that has come into the remote storage via the Appender interface, in seconds since epoch.",
}),
},
}
if reg != nil {
reg.MustRegister(rws.highestTimestamp)
}
go rws.run()
return rws
}
func (rws *WriteStorage) run() {
ticker := time.NewTicker(shardUpdateDuration)
defer ticker.Stop()
for range ticker.C {
rws.samplesIn.tick()
}
}
// ApplyConfig updates the state as the new config requires.
// Only stop & create queues which have changes.
func (rws *WriteStorage) ApplyConfig(conf *config.Config) error {
rws.mtx.Lock()
defer rws.mtx.Unlock()
// Remote write queues only need to change if the remote write config or
// external labels change.
externalLabelUnchanged := labels.Equal(conf.GlobalConfig.ExternalLabels, rws.externalLabels)
rws.externalLabels = conf.GlobalConfig.ExternalLabels
newQueues := make(map[string]*QueueManager)
newHashes := []string{}
for _, rwConf := range conf.RemoteWriteConfigs {
hash, err := toHash(rwConf)
if err != nil {
return err
}
// Don't allow duplicate remote write configs.
if _, ok := newQueues[hash]; ok {
return fmt.Errorf("duplicate remote write configs are not allowed, found duplicate for URL: %s", rwConf.URL)
}
// Set the queue name to the config hash if the user has not set
// a name in their remote write config so we can still differentiate
// between queues that have the same remote write endpoint.
name := hash[:6]
if rwConf.Name != "" {
name = rwConf.Name
}
c, err := NewWriteClient(name, &ClientConfig{
URL: rwConf.URL,
Timeout: rwConf.RemoteTimeout,
HTTPClientConfig: rwConf.HTTPClientConfig,
SigV4Config: rwConf.SigV4Config,
Headers: rwConf.Headers,
RetryOnRateLimit: rwConf.QueueConfig.RetryOnRateLimit,
})
if err != nil {
return err
}
queue, ok := rws.queues[hash]
if externalLabelUnchanged && ok {
// Update the client in case any secret configuration has changed.
queue.SetClient(c)
newQueues[hash] = queue
delete(rws.queues, hash)
continue
}
endpoint := rwConf.URL.String()
newQueues[hash] = NewQueueManager(
newQueueManagerMetrics(rws.reg, name, endpoint),
rws.watcherMetrics,
rws.liveReaderMetrics,
rws.logger,
rws.walDir,
rws.samplesIn,
rwConf.QueueConfig,
rwConf.MetadataConfig,
conf.GlobalConfig.ExternalLabels,
rwConf.WriteRelabelConfigs,
c,
rws.flushDeadline,
rws.interner,
rws.highestTimestamp,
rws.scraper,
rwConf.SendExemplars,
)
// Keep track of which queues are new so we know which to start.
newHashes = append(newHashes, hash)
}
// Anything remaining in rws.queues is a queue who's config has
// changed or was removed from the overall remote write config.
for _, q := range rws.queues {
q.Stop()
}
for _, hash := range newHashes {
newQueues[hash].Start()
}
rws.queues = newQueues
return nil
}
// Appender implements storage.Storage.
func (rws *WriteStorage) Appender(_ context.Context) storage.Appender {
return &timestampTracker{
writeStorage: rws,
highestRecvTimestamp: rws.highestTimestamp,
}
}
// Close closes the WriteStorage.
func (rws *WriteStorage) Close() error {
rws.mtx.Lock()
defer rws.mtx.Unlock()
for _, q := range rws.queues {
q.Stop()
}
return nil
}
type timestampTracker struct {
writeStorage *WriteStorage
samples int64
exemplars int64
histograms int64
highestTimestamp int64
highestRecvTimestamp *maxTimestamp
}
// Append implements storage.Appender.
func (t *timestampTracker) Append(_ uint64, _ labels.Labels, ts int64, _ float64) (uint64, error) {
t.samples++
if ts > t.highestTimestamp {
t.highestTimestamp = ts
}
return 0, nil
}
func (t *timestampTracker) AppendExemplar(_ uint64, _ labels.Labels, _ exemplar.Exemplar) (uint64, error) {
t.exemplars++
return 0, nil
}
func (t *timestampTracker) AppendHistogram(_ uint64, _ labels.Labels, ts int64, _ histogram.SparseHistogram) (uint64, error) {
t.histograms++
if ts > t.highestTimestamp {
t.highestTimestamp = ts
}
return 0, nil
}
// Commit implements storage.Appender.
func (t *timestampTracker) Commit() error {
t.writeStorage.samplesIn.incr(t.samples + t.exemplars)
samplesIn.Add(float64(t.samples))
exemplarsIn.Add(float64(t.exemplars))
t.highestRecvTimestamp.Set(float64(t.highestTimestamp / 1000))
return nil
}
// Rollback implements storage.Appender.
func (*timestampTracker) Rollback() error {
return nil
}