prometheus/storage/remote/write_handler.go
2024-04-22 14:48:21 +01:00

457 lines
15 KiB
Go

// Copyright 2021 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"
"errors"
"fmt"
"io"
"net/http"
"github.com/go-kit/log"
"github.com/go-kit/log/level"
"github.com/gogo/protobuf/proto"
"github.com/golang/snappy"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/prometheus/config"
"github.com/prometheus/prometheus/model/exemplar"
"github.com/prometheus/prometheus/model/labels"
"github.com/prometheus/prometheus/prompb"
writev2 "github.com/prometheus/prometheus/prompb/write/v2"
"github.com/prometheus/prometheus/storage"
otlptranslator "github.com/prometheus/prometheus/storage/remote/otlptranslator/prometheusremotewrite"
)
type writeHandler struct {
logger log.Logger
appendable storage.Appendable
samplesWithInvalidLabelsTotal prometheus.Counter
// PRW 2.0 definies backward compatible content negotiation across prototypes
// and compressions.
protoTypes []config.RemoteWriteProtoType
acceptHeaderValue string
compressions []config.RemoteWriteCompression
acceptEncodingHeaderValue string
}
// NewWriteHandler creates a http.Handler that accepts remote write requests and
// writes them to the provided appendable.
// Compatible with both 1.x and 2.0 spec.
func NewWriteHandler(logger log.Logger, reg prometheus.Registerer, appendable storage.Appendable, protoTypes []config.RemoteWriteProtoType, compressions []config.RemoteWriteCompression) http.Handler {
h := &writeHandler{
logger: logger,
appendable: appendable,
protoTypes: protoTypes,
acceptHeaderValue: config.RemoteWriteProtoTypes(protoTypes).ServerAcceptHeaderValue(),
compressions: compressions,
acceptEncodingHeaderValue: config.RemoteWriteCompressions(compressions).ServerAcceptEncodingHeaderValue(),
samplesWithInvalidLabelsTotal: prometheus.NewCounter(prometheus.CounterOpts{
Namespace: "prometheus",
Subsystem: "api",
Name: "remote_write_invalid_labels_samples_total",
Help: "The total number of remote write samples which contains invalid labels.",
}),
}
if reg != nil {
reg.MustRegister(h.samplesWithInvalidLabelsTotal)
}
return h
}
func (h *writeHandler) parseEncoding(contentEncoding string) (config.RemoteWriteCompression, error) {
// TODO(bwplotka): TBD
got := config.RemoteWriteCompression(contentEncoding)
if err := got.Validate(); err != nil {
return "", err // TODO(bwplotka): Wrap properly
}
// TODO(bwplotka): Build utils for this.
for _, c := range h.compressions {
if c == got {
return got, nil
}
}
return "", fmt.Errorf("unsupported compression, got %v, supported %v", got, h.acceptEncodingHeaderValue)
}
func (h *writeHandler) parseType(contentType string) (config.RemoteWriteProtoType, error) {
// TODO(bwplotka): TBD
got := config.RemoteWriteProtoType(contentType)
if err := got.Validate(); err != nil {
return "", err // TODO(bwplotka): Wrap properly
}
// TODO(bwplotka): Build utils for this.
for _, c := range h.protoTypes {
if c == got {
return got, nil
}
}
return "", fmt.Errorf("unsupported proto type, got %v, supported %v", got, h.acceptHeaderValue)
}
func (h *writeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// Start with ensuring receiver response headers indicate PRW 2.0 and accepted
// content type and compressions.
w.Header().Set("Accept", h.acceptHeaderValue)
w.Header().Set("Accept-Encoding", h.acceptEncodingHeaderValue)
// Initial content type and encoding negotiation.
// NOTE: PRW 2.0 deprecated X-Prometheus-Remote-Write-Version, ignore it, we
// rely on content-type header only.
enc, err := h.parseEncoding(r.Header.Get("Content-Encoding"))
if err != nil {
w.WriteHeader(http.StatusUnsupportedMediaType)
w.Write([]byte(err.Error())) // TODO(bwplotka) Format? Log?
return
}
typ, err := h.parseType(r.Header.Get("Content-Type"))
if err != nil {
w.WriteHeader(http.StatusUnsupportedMediaType)
w.Write([]byte(err.Error())) // TODO(bwplotka) Format? Log? use http.Error
return
}
// Read the request body.
body, err := io.ReadAll(r.Body)
if err != nil {
level.Error(h.logger).Log("msg", "Error decoding remote write request", "err", err.Error())
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
var decompressed []byte
switch enc {
case config.RemoteWriteCompressionSnappy:
decompressed, err = snappy.Decode(nil, body)
if err != nil {
level.Error(h.logger).Log("msg", "Error decoding remote write request", "err", err.Error())
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
default:
panic("should not happen")
}
switch typ {
case config.RemoteWriteProtoTypeV1:
var req prompb.WriteRequest
if err := proto.Unmarshal(decompressed, &req); err != nil {
level.Error(h.logger).Log("msg", "Error decoding remote write request", "err", err.Error())
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
err = h.write(r.Context(), &req)
case config.RemoteWriteProtoTypeV2:
// 2.0 request.
var reqMinStr writev2.WriteRequest
if err := proto.Unmarshal(decompressed, &reqMinStr); err != nil {
level.Error(h.logger).Log("msg", "Error decoding remote write request", "err", err.Error())
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
err = h.writeMinStr(r.Context(), &reqMinStr)
default:
panic("should not happen")
}
switch {
case err == nil:
case errors.Is(err, storage.ErrOutOfOrderSample), errors.Is(err, storage.ErrOutOfBounds), errors.Is(err, storage.ErrDuplicateSampleForTimestamp), errors.Is(err, storage.ErrTooOldSample):
// Indicated an out of order sample is a bad request to prevent retries.
http.Error(w, err.Error(), http.StatusBadRequest)
return
default:
level.Error(h.logger).Log("msg", "Error appending remote write", "err", err.Error())
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.WriteHeader(http.StatusNoContent)
}
// checkAppendExemplarError modifies the AppendExemplar's returned error based on the error cause.
func (h *writeHandler) checkAppendExemplarError(err error, e exemplar.Exemplar, outOfOrderErrs *int) error {
unwrappedErr := errors.Unwrap(err)
if unwrappedErr == nil {
unwrappedErr = err
}
switch {
case errors.Is(unwrappedErr, storage.ErrNotFound):
return storage.ErrNotFound
case errors.Is(unwrappedErr, storage.ErrOutOfOrderExemplar):
*outOfOrderErrs++
level.Debug(h.logger).Log("msg", "Out of order exemplar", "exemplar", fmt.Sprintf("%+v", e))
return nil
default:
return err
}
}
func (h *writeHandler) write(ctx context.Context, req *prompb.WriteRequest) (err error) {
outOfOrderExemplarErrs := 0
samplesWithInvalidLabels := 0
app := h.appendable.Appender(ctx)
defer func() {
if err != nil {
_ = app.Rollback()
return
}
err = app.Commit()
}()
b := labels.NewScratchBuilder(0)
for _, ts := range req.Timeseries {
ls := labelProtosToLabels(&b, ts.Labels)
if !ls.IsValid() {
level.Warn(h.logger).Log("msg", "Invalid metric names or labels", "got", ls.String())
samplesWithInvalidLabels++
continue
}
err := h.appendSamples(app, ts.Samples, ls)
if err != nil {
return err
}
for _, ep := range ts.Exemplars {
e := exemplarProtoToExemplar(&b, ep)
h.appendExemplar(app, e, ls, &outOfOrderExemplarErrs)
}
err = h.appendHistograms(app, ts.Histograms, ls)
if err != nil {
return err
}
}
if outOfOrderExemplarErrs > 0 {
_ = level.Warn(h.logger).Log("msg", "Error on ingesting out-of-order exemplars", "num_dropped", outOfOrderExemplarErrs)
}
if samplesWithInvalidLabels > 0 {
h.samplesWithInvalidLabelsTotal.Add(float64(samplesWithInvalidLabels))
}
return nil
}
func (h *writeHandler) appendExemplar(app storage.Appender, e exemplar.Exemplar, labels labels.Labels, outOfOrderExemplarErrs *int) {
_, err := app.AppendExemplar(0, labels, e)
err = h.checkAppendExemplarError(err, e, outOfOrderExemplarErrs)
if err != nil {
// Since exemplar storage is still experimental, we don't fail the request on ingestion errors
level.Debug(h.logger).Log("msg", "Error while adding exemplar in AddExemplar", "exemplar", fmt.Sprintf("%+v", e), "err", err)
}
}
func (h *writeHandler) appendSamples(app storage.Appender, ss []prompb.Sample, labels labels.Labels) error {
var ref storage.SeriesRef
var err error
for _, s := range ss {
ref, err = app.Append(ref, labels, s.GetTimestamp(), s.GetValue())
if err != nil {
unwrappedErr := errors.Unwrap(err)
if unwrappedErr == nil {
unwrappedErr = err
}
if errors.Is(err, storage.ErrOutOfOrderSample) || errors.Is(unwrappedErr, storage.ErrOutOfBounds) || errors.Is(unwrappedErr, storage.ErrDuplicateSampleForTimestamp) {
level.Error(h.logger).Log("msg", "Out of order sample from remote write", "err", err.Error(), "series", labels.String(), "timestamp", s.Timestamp)
}
return err
}
}
return nil
}
func (h *writeHandler) appendMinSamples(app storage.Appender, ss []writev2.Sample, labels labels.Labels) error {
var ref storage.SeriesRef
var err error
for _, s := range ss {
ref, err = app.Append(ref, labels, s.GetTimestamp(), s.GetValue())
if err != nil {
unwrappedErr := errors.Unwrap(err)
if unwrappedErr == nil {
unwrappedErr = err
}
if errors.Is(err, storage.ErrOutOfOrderSample) || errors.Is(unwrappedErr, storage.ErrOutOfBounds) || errors.Is(unwrappedErr, storage.ErrDuplicateSampleForTimestamp) {
level.Error(h.logger).Log("msg", "Out of order sample from remote write", "err", err.Error(), "series", labels.String(), "timestamp", s.Timestamp)
}
return err
}
}
return nil
}
func (h *writeHandler) appendHistograms(app storage.Appender, hh []prompb.Histogram, labels labels.Labels) error {
var err error
for _, hp := range hh {
if hp.IsFloatHistogram() {
fhs := FloatHistogramProtoToFloatHistogram(hp)
_, err = app.AppendHistogram(0, labels, hp.Timestamp, nil, fhs)
} else {
hs := HistogramProtoToHistogram(hp)
_, err = app.AppendHistogram(0, labels, hp.Timestamp, hs, nil)
}
if err != nil {
unwrappedErr := errors.Unwrap(err)
if unwrappedErr == nil {
unwrappedErr = err
}
// Although AppendHistogram does not currently return ErrDuplicateSampleForTimestamp there is
// a note indicating its inclusion in the future.
if errors.Is(unwrappedErr, storage.ErrOutOfOrderSample) || errors.Is(unwrappedErr, storage.ErrOutOfBounds) || errors.Is(unwrappedErr, storage.ErrDuplicateSampleForTimestamp) {
level.Error(h.logger).Log("msg", "Out of order histogram from remote write", "err", err.Error(), "series", labels.String(), "timestamp", hp.Timestamp)
}
return err
}
}
return nil
}
func (h *writeHandler) appendMinHistograms(app storage.Appender, hh []writev2.Histogram, labels labels.Labels) error {
var err error
for _, hp := range hh {
if hp.IsFloatHistogram() {
fhs := FloatMinHistogramProtoToFloatHistogram(hp)
_, err = app.AppendHistogram(0, labels, hp.Timestamp, nil, fhs)
} else {
hs := MinHistogramProtoToHistogram(hp)
_, err = app.AppendHistogram(0, labels, hp.Timestamp, hs, nil)
}
if err != nil {
unwrappedErr := errors.Unwrap(err)
if unwrappedErr == nil {
unwrappedErr = err
}
// Although AppendHistogram does not currently return ErrDuplicateSampleForTimestamp there is
// a note indicating its inclusion in the future.
if errors.Is(unwrappedErr, storage.ErrOutOfOrderSample) || errors.Is(unwrappedErr, storage.ErrOutOfBounds) || errors.Is(unwrappedErr, storage.ErrDuplicateSampleForTimestamp) {
level.Error(h.logger).Log("msg", "Out of order histogram from remote write", "err", err.Error(), "series", labels.String(), "timestamp", hp.Timestamp)
}
return err
}
}
return nil
}
// NewOTLPWriteHandler creates a http.Handler that accepts OTLP write requests and
// writes them to the provided appendable.
func NewOTLPWriteHandler(logger log.Logger, appendable storage.Appendable) http.Handler {
rwHandler := &writeHandler{
logger: logger,
appendable: appendable,
}
return &otlpWriteHandler{
logger: logger,
rwHandler: rwHandler,
}
}
type otlpWriteHandler struct {
logger log.Logger
rwHandler *writeHandler
}
func (h *otlpWriteHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
req, err := DecodeOTLPWriteRequest(r)
if err != nil {
level.Error(h.logger).Log("msg", "Error decoding remote write request", "err", err.Error())
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
prwMetricsMap, errs := otlptranslator.FromMetrics(req.Metrics(), otlptranslator.Settings{
AddMetricSuffixes: true,
})
if errs != nil {
level.Warn(h.logger).Log("msg", "Error translating OTLP metrics to Prometheus write request", "err", errs)
}
prwMetrics := make([]prompb.TimeSeries, 0, len(prwMetricsMap))
for _, ts := range prwMetricsMap {
prwMetrics = append(prwMetrics, *ts)
}
err = h.rwHandler.write(r.Context(), &prompb.WriteRequest{
Timeseries: prwMetrics,
})
switch {
case err == nil:
case errors.Is(err, storage.ErrOutOfOrderSample), errors.Is(err, storage.ErrOutOfBounds), errors.Is(err, storage.ErrDuplicateSampleForTimestamp):
// Indicated an out of order sample is a bad request to prevent retries.
http.Error(w, err.Error(), http.StatusBadRequest)
return
default:
level.Error(h.logger).Log("msg", "Error appending remote write", "err", err.Error())
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.WriteHeader(http.StatusOK)
}
func (h *writeHandler) writeMinStr(ctx context.Context, req *writev2.WriteRequest) (err error) {
outOfOrderExemplarErrs := 0
app := h.appendable.Appender(ctx)
defer func() {
if err != nil {
_ = app.Rollback()
return
}
err = app.Commit()
}()
for _, ts := range req.Timeseries {
ls := labelProtosV2ToLabels(ts.LabelsRefs, req.Symbols)
err := h.appendMinSamples(app, ts.Samples, ls)
if err != nil {
return err
}
for _, ep := range ts.Exemplars {
e := exemplarProtoV2ToExemplar(ep, req.Symbols)
h.appendExemplar(app, e, ls, &outOfOrderExemplarErrs)
}
err = h.appendMinHistograms(app, ts.Histograms, ls)
if err != nil {
return err
}
m := metadataProtoV2ToMetadata(ts.Metadata, req.Symbols)
if _, err = app.UpdateMetadata(0, ls, m); err != nil {
level.Debug(h.logger).Log("msg", "error while updating metadata from remote write", "err", err)
}
}
if outOfOrderExemplarErrs > 0 {
_ = level.Warn(h.logger).Log("msg", "Error on ingesting out-of-order exemplars", "num_dropped", outOfOrderExemplarErrs)
}
return nil
}