no-brainer copypaste but more performance write support

storage/remote/codec.go

@@ -770,6 +770,29 @@ func labelProtosToLabels(labelPairs []prompb.Label) labels.Labels {
 	return b.Labels()
 }
 
+func labelRefProtosToLabels(st map[uint64]string, lbls []prompb.LabelRef) labels.Labels {
+	result := make(labels.Labels, 0, len(lbls))
+	for _, l := range lbls {
+		result = append(result, labels.Label{
+			Name:  st[l.NameRef],
+			Value: st[l.ValueRef],
+		})
+	}
+	sort.Sort(result)
+	return result
+}
+
+func exemplarRefProtoToExemplar(st map[uint64]string, ep prompb.ExemplarRef) exemplar.Exemplar {
+	timestamp := ep.Timestamp
+
+	return exemplar.Exemplar{
+		Labels: labelRefProtosToLabels(st, ep.Labels),
+		Value:  ep.Value,
+		Ts:     timestamp,
+		HasTs:  timestamp != 0,
+	}
+}
+
 // labelsToLabelsProto transforms labels into prompb labels. The buffer slice
 // will be used to avoid allocations if it is big enough to store the labels.
 func labelsToLabelsProto(lbls labels.Labels, buf []prompb.Label) []prompb.Label {
@@ -908,6 +931,7 @@ func ReducedWriteRequestToWriteRequest(redReq *prompb.WriteRequestWithRefs) (*pr
 			exemplars[j].Value = e.Value
 			exemplars[j].Timestamp = e.Timestamp
 			exemplars[j].Labels = make([]prompb.Label, len(e.Labels))
+
 			for k, l := range e.Labels {
 				exemplars[j].Labels[k].Name = redReq.StringSymbolTable[l.NameRef]
 				exemplars[j].Labels[k].Value = redReq.StringSymbolTable[l.ValueRef]

storage/remote/write_handler.go

@@ -64,12 +64,9 @@ func NewWriteHandler(logger log.Logger, reg prometheus.Registerer, appendable st
 func (h *writeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	var err error
 	var req *prompb.WriteRequest
+	var reqWithRefs *prompb.WriteRequestWithRefs
 	if h.internFormat {
-		var redReq *prompb.WriteRequestWithRefs
+		reqWithRefs, err = DecodeReducedWriteRequest(r.Body)
-		redReq, err = DecodeReducedWriteRequest(r.Body)
-		if err == nil {
-			req, err = ReducedWriteRequestToWriteRequest(redReq)
-		}
 	} else {
 		req, err = DecodeWriteRequest(r.Body)
 	}
@@ -80,7 +77,11 @@ func (h *writeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if h.internFormat {
+		err = h.writeReduced(r.Context(), reqWithRefs)
+	} else {
 		err = h.write(r.Context(), req)
+	}
 	switch err {
 	case nil:
 	case storage.ErrOutOfOrderSample, storage.ErrOutOfBounds, storage.ErrDuplicateSampleForTimestamp:
@@ -251,3 +252,70 @@ func (h *otlpWriteHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	w.WriteHeader(http.StatusOK)
 }
+
+func (h *writeHandler) writeReduced(ctx context.Context, req *prompb.WriteRequestWithRefs) (err error) {
+	outOfOrderExemplarErrs := 0
+
+	app := h.appendable.Appender(ctx)
+	defer func() {
+		if err != nil {
+			_ = app.Rollback()
+			return
+		}
+		err = app.Commit()
+	}()
+
+	var exemplarErr error
+	for _, ts := range req.Timeseries {
+		labels := labelRefProtosToLabels(req.StringSymbolTable, ts.Labels)
+
+		for _, s := range ts.Samples {
+			_, err = app.Append(0, labels, s.Timestamp, s.Value)
+			if err != nil {
+				unwrapedErr := errors.Unwrap(err)
+				if errors.Is(unwrapedErr, storage.ErrOutOfOrderSample) || errors.Is(unwrapedErr, storage.ErrOutOfBounds) || errors.Is(unwrapedErr, 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
+			}
+
+		}
+
+		for _, ep := range ts.Exemplars {
+			e := exemplarRefProtoToExemplar(req.StringSymbolTable, ep)
+
+			_, exemplarErr = app.AppendExemplar(0, labels, e)
+			exemplarErr = h.checkAppendExemplarError(exemplarErr, e, &outOfOrderExemplarErrs)
+			if exemplarErr != 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", exemplarErr)
+			}
+		}
+
+		for _, hp := range ts.Histograms {
+			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)
+				// Althogh 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
+			}
+		}
+	}
+
+	if outOfOrderExemplarErrs > 0 {
+		_ = level.Warn(h.logger).Log("msg", "Error on ingesting out-of-order exemplars", "num_dropped", outOfOrderExemplarErrs)
+	}
+
+	return nil
+}