Merge pull request #3336 from tomwilkie/remote-api-update

Update remote storage APIs from 1.8 branch

storage/remote/client.go

@@ -44,26 +44,27 @@ type Client struct {
 	readRecent bool
 }
 
-type clientConfig struct {
-	url              *config.URL
-	timeout          model.Duration
-	readRecent       bool
-	httpClientConfig config.HTTPClientConfig
+// ClientConfig configures a Client.
+type ClientConfig struct {
+	URL              *config.URL
+	Timeout          model.Duration
+	ReadRecent       bool
+	HTTPClientConfig config.HTTPClientConfig
 }
 
 // NewClient creates a new Client.
-func NewClient(index int, conf *clientConfig) (*Client, error) {
-	httpClient, err := httputil.NewClientFromConfig(conf.httpClientConfig, "remote_storage")
+func NewClient(index int, conf *ClientConfig) (*Client, error) {
+	httpClient, err := httputil.NewClientFromConfig(conf.HTTPClientConfig, "remote_storage")
 	if err != nil {
 		return nil, err
 	}
 
 	return &Client{
 		index:      index,
-		url:        conf.url,
+		url:        conf.URL,
 		client:     httpClient,
-		timeout:    time.Duration(conf.timeout),
-		readRecent: conf.readRecent,
+		timeout:    time.Duration(conf.Timeout),
+		readRecent: conf.ReadRecent,
 	}, nil
 }
 
@@ -72,30 +73,7 @@ type recoverableError struct {
 }
 
 // Store sends a batch of samples to the HTTP endpoint.
-func (c *Client) Store(samples model.Samples) error {
-	req := &prompb.WriteRequest{
-		Timeseries: make([]*prompb.TimeSeries, 0, len(samples)),
-	}
-	for _, s := range samples {
-		ts := &prompb.TimeSeries{
-			Labels: make([]*prompb.Label, 0, len(s.Metric)),
-		}
-		for k, v := range s.Metric {
-			ts.Labels = append(ts.Labels,
-				&prompb.Label{
-					Name:  string(k),
-					Value: string(v),
-				})
-		}
-		ts.Samples = []*prompb.Sample{
-			{
-				Value:     float64(s.Value),
-				Timestamp: int64(s.Timestamp),
-			},
-		}
-		req.Timeseries = append(req.Timeseries, ts)
-	}
-
+func (c *Client) Store(req *prompb.WriteRequest) error {
 	data, err := proto.Marshal(req)
 	if err != nil {
 		return err
@@ -143,17 +121,14 @@ func (c Client) Name() string {
 }
 
 // Read reads from a remote endpoint.
-func (c *Client) Read(ctx context.Context, from, through int64, matchers []*prompb.LabelMatcher) ([]*prompb.TimeSeries, error) {
+func (c *Client) Read(ctx context.Context, query *prompb.Query) (*prompb.QueryResult, error) {
 	req := &prompb.ReadRequest{
 		// TODO: Support batching multiple queries into one read request,
 		// as the protobuf interface allows for it.
-		Queries: []*prompb.Query{{
-			StartTimestampMs: from,
-			EndTimestampMs:   through,
-			Matchers:         matchers,
-		}},
+		Queries: []*prompb.Query{
+			query,
+		},
 	}
-
 	data, err := proto.Marshal(req)
 	if err != nil {
 		return nil, fmt.Errorf("unable to marshal read request: %v", err)
@@ -200,5 +175,5 @@ func (c *Client) Read(ctx context.Context, from, through int64, matchers []*prom
 		return nil, fmt.Errorf("responses: want %d, got %d", len(req.Queries), len(resp.Results))
 	}
 
-	return resp.Results[0].Timeseries, nil
+	return resp.Results[0], nil
 }

storage/remote/client_test.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/config"
+	"github.com/prometheus/prometheus/prompb"
 )
 
 var longErrMessage = strings.Repeat("error message", maxErrMsgLen)
@@ -64,15 +65,15 @@ func TestStoreHTTPErrorHandling(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		c, err := NewClient(0, &clientConfig{
-			url:     &config.URL{serverURL},
-			timeout: model.Duration(time.Second),
+		c, err := NewClient(0, &ClientConfig{
+			URL:     &config.URL{URL: serverURL},
+			Timeout: model.Duration(time.Second),
 		})
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		err = c.Store(nil)
+		err = c.Store(&prompb.WriteRequest{})
 		if !reflect.DeepEqual(err, test.err) {
 			t.Errorf("%d. Unexpected error; want %v, got %v", i, test.err, err)
 		}

storage/remote/codec.go

@@ -0,0 +1,368 @@
+// 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 (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sort"
+
+	"github.com/gogo/protobuf/proto"
+	"github.com/golang/snappy"
+	"github.com/prometheus/common/model"
+
+	"github.com/prometheus/prometheus/pkg/labels"
+	"github.com/prometheus/prometheus/prompb"
+	"github.com/prometheus/prometheus/storage"
+)
+
+// DecodeReadRequest reads a remote.Request from a http.Request.
+func DecodeReadRequest(r *http.Request) (*prompb.ReadRequest, error) {
+	compressed, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	reqBuf, err := snappy.Decode(nil, compressed)
+	if err != nil {
+		return nil, err
+	}
+
+	var req prompb.ReadRequest
+	if err := proto.Unmarshal(reqBuf, &req); err != nil {
+		return nil, err
+	}
+
+	return &req, nil
+}
+
+// EncodeReadResponse writes a remote.Response to a http.ResponseWriter.
+func EncodeReadResponse(resp *prompb.ReadResponse, w http.ResponseWriter) error {
+	data, err := proto.Marshal(resp)
+	if err != nil {
+		return err
+	}
+
+	w.Header().Set("Content-Type", "application/x-protobuf")
+	w.Header().Set("Content-Encoding", "snappy")
+
+	compressed := snappy.Encode(nil, data)
+	_, err = w.Write(compressed)
+	return err
+}
+
+// ToWriteRequest converts an array of samples into a WriteRequest proto.
+func ToWriteRequest(samples []*model.Sample) *prompb.WriteRequest {
+	req := &prompb.WriteRequest{
+		Timeseries: make([]*prompb.TimeSeries, 0, len(samples)),
+	}
+
+	for _, s := range samples {
+		ts := prompb.TimeSeries{
+			Labels: MetricToLabelProtos(s.Metric),
+			Samples: []*prompb.Sample{
+				{
+					Value:     float64(s.Value),
+					Timestamp: int64(s.Timestamp),
+				},
+			},
+		}
+		req.Timeseries = append(req.Timeseries, &ts)
+	}
+
+	return req
+}
+
+// ToQuery builds a Query proto.
+func ToQuery(from, to int64, matchers []*labels.Matcher) (*prompb.Query, error) {
+	ms, err := toLabelMatchers(matchers)
+	if err != nil {
+		return nil, err
+	}
+
+	return &prompb.Query{
+		StartTimestampMs: from,
+		EndTimestampMs:   to,
+		Matchers:         ms,
+	}, nil
+}
+
+// FromQuery unpacks a Query proto.
+func FromQuery(req *prompb.Query) (int64, int64, []*labels.Matcher, error) {
+	matchers, err := fromLabelMatchers(req.Matchers)
+	if err != nil {
+		return 0, 0, nil, err
+	}
+	return req.StartTimestampMs, req.EndTimestampMs, matchers, nil
+}
+
+// ToQueryResult builds a QueryResult proto.
+func ToQueryResult(ss storage.SeriesSet) (*prompb.QueryResult, error) {
+	resp := &prompb.QueryResult{}
+	for ss.Next() {
+		series := ss.At()
+		iter := series.Iterator()
+		samples := []*prompb.Sample{}
+
+		for iter.Next() {
+			ts, val := iter.At()
+			samples = append(samples, &prompb.Sample{
+				Timestamp: ts,
+				Value:     val,
+			})
+		}
+		if err := iter.Err(); err != nil {
+			return nil, err
+		}
+
+		resp.Timeseries = append(resp.Timeseries, &prompb.TimeSeries{
+			Labels:  labelsToLabelsProto(series.Labels()),
+			Samples: samples,
+		})
+	}
+	if err := ss.Err(); err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
+// FromQueryResult unpacks a QueryResult proto.
+func FromQueryResult(res *prompb.QueryResult) storage.SeriesSet {
+	series := make([]storage.Series, 0, len(res.Timeseries))
+	for _, ts := range res.Timeseries {
+		labels := labelProtosToLabels(ts.Labels)
+		if err := validateLabelsAndMetricName(labels); err != nil {
+			return errSeriesSet{err: err}
+		}
+
+		series = append(series, &concreteSeries{
+			labels:  labels,
+			samples: ts.Samples,
+		})
+	}
+	sort.Sort(byLabel(series))
+	return &concreteSeriesSet{
+		series: series,
+	}
+}
+
+// errSeriesSet implements storage.SeriesSet, just returning an error.
+type errSeriesSet struct {
+	err error
+}
+
+func (errSeriesSet) Next() bool {
+	return false
+}
+
+func (errSeriesSet) At() storage.Series {
+	return nil
+}
+
+func (e errSeriesSet) Err() error {
+	return e.err
+}
+
+// concreteSeriesSet implements storage.SeriesSet.
+type concreteSeriesSet struct {
+	cur    int
+	series []storage.Series
+}
+
+func (c *concreteSeriesSet) Next() bool {
+	c.cur++
+	return c.cur-1 < len(c.series)
+}
+
+func (c *concreteSeriesSet) At() storage.Series {
+	return c.series[c.cur-1]
+}
+
+func (c *concreteSeriesSet) Err() error {
+	return nil
+}
+
+// concreteSeries implementes storage.Series.
+type concreteSeries struct {
+	labels  labels.Labels
+	samples []*prompb.Sample
+}
+
+func (c *concreteSeries) Labels() labels.Labels {
+	return c.labels
+}
+
+func (c *concreteSeries) Iterator() storage.SeriesIterator {
+	return newConcreteSeriersIterator(c)
+}
+
+// concreteSeriesIterator implements storage.SeriesIterator.
+type concreteSeriesIterator struct {
+	cur    int
+	series *concreteSeries
+}
+
+func newConcreteSeriersIterator(series *concreteSeries) storage.SeriesIterator {
+	return &concreteSeriesIterator{
+		cur:    -1,
+		series: series,
+	}
+}
+
+// Seek implements storage.SeriesIterator.
+func (c *concreteSeriesIterator) Seek(t int64) bool {
+	c.cur = sort.Search(len(c.series.samples), func(n int) bool {
+		return c.series.samples[n].Timestamp >= t
+	})
+	return c.cur < len(c.series.samples)
+}
+
+// At implements storage.SeriesIterator.
+func (c *concreteSeriesIterator) At() (t int64, v float64) {
+	s := c.series.samples[c.cur]
+	return s.Timestamp, s.Value
+}
+
+// Next implements storage.SeriesIterator.
+func (c *concreteSeriesIterator) Next() bool {
+	c.cur++
+	return c.cur < len(c.series.samples)
+}
+
+// Err implements storage.SeriesIterator.
+func (c *concreteSeriesIterator) Err() error {
+	return nil
+}
+
+// validateLabelsAndMetricName validates the label names/values and metric names returned from remote read.
+func validateLabelsAndMetricName(ls labels.Labels) error {
+	for _, l := range ls {
+		if l.Name == labels.MetricName && !model.IsValidMetricName(model.LabelValue(l.Value)) {
+			return fmt.Errorf("Invalid metric name: %v", l.Value)
+		}
+		if !model.LabelName(l.Name).IsValid() {
+			return fmt.Errorf("Invalid label name: %v", l.Name)
+		}
+		if !model.LabelValue(l.Value).IsValid() {
+			return fmt.Errorf("Invalid label value: %v", l.Value)
+		}
+	}
+	return nil
+}
+
+func toLabelMatchers(matchers []*labels.Matcher) ([]*prompb.LabelMatcher, error) {
+	pbMatchers := make([]*prompb.LabelMatcher, 0, len(matchers))
+	for _, m := range matchers {
+		var mType prompb.LabelMatcher_Type
+		switch m.Type {
+		case labels.MatchEqual:
+			mType = prompb.LabelMatcher_EQ
+		case labels.MatchNotEqual:
+			mType = prompb.LabelMatcher_NEQ
+		case labels.MatchRegexp:
+			mType = prompb.LabelMatcher_RE
+		case labels.MatchNotRegexp:
+			mType = prompb.LabelMatcher_NRE
+		default:
+			return nil, fmt.Errorf("invalid matcher type")
+		}
+		pbMatchers = append(pbMatchers, &prompb.LabelMatcher{
+			Type:  mType,
+			Name:  m.Name,
+			Value: m.Value,
+		})
+	}
+	return pbMatchers, nil
+}
+
+func fromLabelMatchers(matchers []*prompb.LabelMatcher) ([]*labels.Matcher, error) {
+	result := make([]*labels.Matcher, 0, len(matchers))
+	for _, matcher := range matchers {
+		var mtype labels.MatchType
+		switch matcher.Type {
+		case prompb.LabelMatcher_EQ:
+			mtype = labels.MatchEqual
+		case prompb.LabelMatcher_NEQ:
+			mtype = labels.MatchNotEqual
+		case prompb.LabelMatcher_RE:
+			mtype = labels.MatchRegexp
+		case prompb.LabelMatcher_NRE:
+			mtype = labels.MatchNotRegexp
+		default:
+			return nil, fmt.Errorf("invalid matcher type")
+		}
+		matcher, err := labels.NewMatcher(mtype, matcher.Name, matcher.Value)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, matcher)
+	}
+	return result, nil
+}
+
+// MetricToLabelProtos builds a []*prompb.Label from a model.Metric
+func MetricToLabelProtos(metric model.Metric) []*prompb.Label {
+	labels := make([]*prompb.Label, 0, len(metric))
+	for k, v := range metric {
+		labels = append(labels, &prompb.Label{
+			Name:  string(k),
+			Value: string(v),
+		})
+	}
+	sort.Slice(labels, func(i int, j int) bool {
+		return labels[i].Name < labels[j].Name
+	})
+	return labels
+}
+
+// LabelProtosToMetric unpack a []*prompb.Label to a model.Metric
+func LabelProtosToMetric(labelPairs []*prompb.Label) model.Metric {
+	metric := make(model.Metric, len(labelPairs))
+	for _, l := range labelPairs {
+		metric[model.LabelName(l.Name)] = model.LabelValue(l.Value)
+	}
+	return metric
+}
+
+func labelProtosToLabels(labelPairs []*prompb.Label) labels.Labels {
+	result := make(labels.Labels, 0, len(labelPairs))
+	for _, l := range labelPairs {
+		result = append(result, labels.Label{
+			Name:  l.Name,
+			Value: l.Value,
+		})
+	}
+	sort.Sort(result)
+	return result
+}
+
+func labelsToLabelsProto(labels labels.Labels) []*prompb.Label {
+	result := make([]*prompb.Label, 0, len(labels))
+	for _, l := range labels {
+		result = append(result, &prompb.Label{
+			Name:  l.Name,
+			Value: l.Value,
+		})
+	}
+	return result
+}
+
+func labelsToMetric(ls labels.Labels) model.Metric {
+	metric := make(model.Metric, len(ls))
+	for _, l := range ls {
+		metric[model.LabelName(l.Name)] = model.LabelValue(l.Value)
+	}
+	return metric
+}

storage/remote/codec_test.go

@@ -0,0 +1,126 @@
+// 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 (
+	"testing"
+
+	"github.com/prometheus/prometheus/pkg/labels"
+	"github.com/prometheus/prometheus/prompb"
+	"github.com/prometheus/prometheus/storage"
+)
+
+func TestValidateLabelsAndMetricName(t *testing.T) {
+	tests := []struct {
+		input       labels.Labels
+		expectedErr string
+		shouldPass  bool
+	}{
+		{
+			input: labels.FromStrings(
+				"__name__", "name",
+				"labelName", "labelValue",
+			),
+			expectedErr: "",
+			shouldPass:  true,
+		},
+		{
+			input: labels.FromStrings(
+				"__name__", "name",
+				"_labelName", "labelValue",
+			),
+			expectedErr: "",
+			shouldPass:  true,
+		},
+		{
+			input: labels.FromStrings(
+				"__name__", "name",
+				"@labelName", "labelValue",
+			),
+			expectedErr: "Invalid label name: @labelName",
+			shouldPass:  false,
+		},
+		{
+			input: labels.FromStrings(
+				"__name__", "name",
+				"123labelName", "labelValue",
+			),
+			expectedErr: "Invalid label name: 123labelName",
+			shouldPass:  false,
+		},
+		{
+			input: labels.FromStrings(
+				"__name__", "name",
+				"", "labelValue",
+			),
+			expectedErr: "Invalid label name: ",
+			shouldPass:  false,
+		},
+		{
+			input: labels.FromStrings(
+				"__name__", "name",
+				"labelName", string([]byte{0xff}),
+			),
+			expectedErr: "Invalid label value: " + string([]byte{0xff}),
+			shouldPass:  false,
+		},
+		{
+			input: labels.FromStrings(
+				"__name__", "@invalid_name",
+			),
+			expectedErr: "Invalid metric name: @invalid_name",
+			shouldPass:  false,
+		},
+	}
+
+	for _, test := range tests {
+		err := validateLabelsAndMetricName(test.input)
+		if test.shouldPass != (err == nil) {
+			if test.shouldPass {
+				t.Fatalf("Test should pass, got unexpected error: %v", err)
+			} else {
+				t.Fatalf("Test should fail, unexpected error, got: %v, expected: %v", err, test.expectedErr)
+			}
+		}
+	}
+}
+
+func TestConcreteSeriesSet(t *testing.T) {
+	series1 := &concreteSeries{
+		labels:  labels.FromStrings("foo", "bar"),
+		samples: []*prompb.Sample{&prompb.Sample{Value: 1, Timestamp: 2}},
+	}
+	series2 := &concreteSeries{
+		labels:  labels.FromStrings("foo", "baz"),
+		samples: []*prompb.Sample{&prompb.Sample{Value: 3, Timestamp: 4}},
+	}
+	c := &concreteSeriesSet{
+		series: []storage.Series{series1, series2},
+	}
+	if !c.Next() {
+		t.Fatalf("Expected Next() to be true.")
+	}
+	if c.At() != series1 {
+		t.Fatalf("Unexpected series returned.")
+	}
+	if !c.Next() {
+		t.Fatalf("Expected Next() to be true.")
+	}
+	if c.At() != series2 {
+		t.Fatalf("Unexpected series returned.")
+	}
+	if c.Next() {
+		t.Fatalf("Expected Next() to be false.")
+	}
+}

storage/remote/queue_manager.go

@@ -25,6 +25,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/prometheus/config"
+	"github.com/prometheus/prometheus/prompb"
 	"github.com/prometheus/prometheus/relabel"
 )
 
@@ -124,47 +125,11 @@ func init() {
 	prometheus.MustRegister(numShards)
 }
 
-// QueueManagerConfig is the configuration for the queue used to write to remote
-// storage.
-type QueueManagerConfig struct {
-	// Number of samples to buffer per shard before we start dropping them.
-	QueueCapacity int
-	// Max number of shards, i.e. amount of concurrency.
-	MaxShards int
-	// Maximum number of samples per send.
-	MaxSamplesPerSend int
-	// Maximum time sample will wait in buffer.
-	BatchSendDeadline time.Duration
-	// Max number of times to retry a batch on recoverable errors.
-	MaxRetries int
-	// On recoverable errors, backoff exponentially.
-	MinBackoff time.Duration
-	MaxBackoff time.Duration
-}
-
-// defaultQueueManagerConfig is the default remote queue configuration.
-var defaultQueueManagerConfig = QueueManagerConfig{
-	// With a maximum of 1000 shards, assuming an average of 100ms remote write
-	// time and 100 samples per batch, we will be able to push 1M samples/s.
-	MaxShards:         1000,
-	MaxSamplesPerSend: 100,
-
-	// By default, buffer 1000 batches, which at 100ms per batch is 1:40mins. At
-	// 1000 shards, this will buffer 100M samples total.
-	QueueCapacity:     100 * 1000,
-	BatchSendDeadline: 5 * time.Second,
-
-	// Max number of times to retry a batch on recoverable errors.
-	MaxRetries: 10,
-	MinBackoff: 30 * time.Millisecond,
-	MaxBackoff: 100 * time.Millisecond,
-}
-
 // StorageClient defines an interface for sending a batch of samples to an
 // external timeseries database.
 type StorageClient interface {
 	// Store stores the given samples in the remote storage.
-	Store(model.Samples) error
+	Store(*prompb.WriteRequest) error
 	// Name identifies the remote storage implementation.
 	Name() string
 }
@@ -174,7 +139,7 @@ type StorageClient interface {
 type QueueManager struct {
 	logger log.Logger
 
-	cfg            QueueManagerConfig
+	cfg            config.QueueConfig
 	externalLabels model.LabelSet
 	relabelConfigs []*config.RelabelConfig
 	client         StorageClient
@@ -193,7 +158,7 @@ type QueueManager struct {
 }
 
 // NewQueueManager builds a new QueueManager.
-func NewQueueManager(logger log.Logger, cfg QueueManagerConfig, externalLabels model.LabelSet, relabelConfigs []*config.RelabelConfig, client StorageClient) *QueueManager {
+func NewQueueManager(logger log.Logger, cfg config.QueueConfig, externalLabels model.LabelSet, relabelConfigs []*config.RelabelConfig, client StorageClient) *QueueManager {
 	if logger == nil {
 		logger = log.NewNopLogger()
 	}
@@ -216,7 +181,13 @@ func NewQueueManager(logger log.Logger, cfg QueueManagerConfig, externalLabels m
 	}
 	t.shards = t.newShards(t.numShards)
 	numShards.WithLabelValues(t.queueName).Set(float64(t.numShards))
-	queueCapacity.WithLabelValues(t.queueName).Set(float64(t.cfg.QueueCapacity))
+	queueCapacity.WithLabelValues(t.queueName).Set(float64(t.cfg.Capacity))
+
+	// Initialise counter labels to zero.
+	sentBatchDuration.WithLabelValues(t.queueName)
+	succeededSamplesTotal.WithLabelValues(t.queueName)
+	failedSamplesTotal.WithLabelValues(t.queueName)
+	droppedSamplesTotal.WithLabelValues(t.queueName)
 
 	return t
 }
@@ -408,7 +379,7 @@ type shards struct {
 func (t *QueueManager) newShards(numShards int) *shards {
 	queues := make([]chan *model.Sample, numShards)
 	for i := 0; i < numShards; i++ {
-		queues[i] = make(chan *model.Sample, t.cfg.QueueCapacity)
+		queues[i] = make(chan *model.Sample, t.cfg.Capacity)
 	}
 	s := &shards{
 		qm:     t,
@@ -502,7 +473,8 @@ func (s *shards) sendSamplesWithBackoff(samples model.Samples) {
 	backoff := s.qm.cfg.MinBackoff
 	for retries := s.qm.cfg.MaxRetries; retries > 0; retries-- {
 		begin := time.Now()
-		err := s.qm.client.Store(samples)
+		req := ToWriteRequest(samples)
+		err := s.qm.client.Store(req)
 
 		sentBatchDuration.WithLabelValues(s.qm.queueName).Observe(time.Since(begin).Seconds())
 		if err == nil {

storage/remote/queue_manager_test.go

@@ -15,25 +15,28 @@ package remote
 
 import (
 	"fmt"
+	"reflect"
 	"sync"
 	"sync/atomic"
 	"testing"
 	"time"
 
 	"github.com/prometheus/common/model"
+	"github.com/prometheus/prometheus/config"
+	"github.com/prometheus/prometheus/prompb"
 )
 
 type TestStorageClient struct {
-	receivedSamples map[string]model.Samples
-	expectedSamples map[string]model.Samples
+	receivedSamples map[string][]*prompb.Sample
+	expectedSamples map[string][]*prompb.Sample
 	wg              sync.WaitGroup
 	mtx             sync.Mutex
 }
 
 func NewTestStorageClient() *TestStorageClient {
 	return &TestStorageClient{
-		receivedSamples: map[string]model.Samples{},
-		expectedSamples: map[string]model.Samples{},
+		receivedSamples: map[string][]*prompb.Sample{},
+		expectedSamples: map[string][]*prompb.Sample{},
 	}
 }
 
@@ -42,8 +45,11 @@ func (c *TestStorageClient) expectSamples(ss model.Samples) {
 	defer c.mtx.Unlock()
 
 	for _, s := range ss {
-		ts := s.Metric.String()
-		c.expectedSamples[ts] = append(c.expectedSamples[ts], s)
+		ts := labelProtosToLabels(MetricToLabelProtos(s.Metric)).String()
+		c.expectedSamples[ts] = append(c.expectedSamples[ts], &prompb.Sample{
+			Timestamp: int64(s.Timestamp),
+			Value:     float64(s.Value),
+		})
 	}
 	c.wg.Add(len(ss))
 }
@@ -54,23 +60,24 @@ func (c *TestStorageClient) waitForExpectedSamples(t *testing.T) {
 	c.mtx.Lock()
 	defer c.mtx.Unlock()
 	for ts, expectedSamples := range c.expectedSamples {
-		for i, expected := range expectedSamples {
-			if !expected.Equal(c.receivedSamples[ts][i]) {
-				t.Fatalf("%d. Expected %v, got %v", i, expected, c.receivedSamples[ts][i])
-			}
+		if !reflect.DeepEqual(expectedSamples, c.receivedSamples[ts]) {
+			t.Fatalf("%s: Expected %v, got %v", ts, expectedSamples, c.receivedSamples[ts])
 		}
 	}
 }
 
-func (c *TestStorageClient) Store(ss model.Samples) error {
+func (c *TestStorageClient) Store(req *prompb.WriteRequest) error {
 	c.mtx.Lock()
 	defer c.mtx.Unlock()
-
-	for _, s := range ss {
-		ts := s.Metric.String()
-		c.receivedSamples[ts] = append(c.receivedSamples[ts], s)
+	count := 0
+	for _, ts := range req.Timeseries {
+		labels := labelProtosToLabels(ts.Labels).String()
+		for _, sample := range ts.Samples {
+			count++
+			c.receivedSamples[labels] = append(c.receivedSamples[labels], sample)
+		}
 	}
-	c.wg.Add(-len(ss))
+	c.wg.Add(-count)
 	return nil
 }
 
@@ -81,7 +88,7 @@ func (c *TestStorageClient) Name() string {
 func TestSampleDelivery(t *testing.T) {
 	// Let's create an even number of send batches so we don't run into the
 	// batch timeout case.
-	n := defaultQueueManagerConfig.QueueCapacity * 2
+	n := config.DefaultQueueConfig.Capacity * 2
 
 	samples := make(model.Samples, 0, n)
 	for i := 0; i < n; i++ {
@@ -97,7 +104,7 @@ func TestSampleDelivery(t *testing.T) {
 	c := NewTestStorageClient()
 	c.expectSamples(samples[:len(samples)/2])
 
-	cfg := defaultQueueManagerConfig
+	cfg := config.DefaultQueueConfig
 	cfg.MaxShards = 1
 	m := NewQueueManager(nil, cfg, nil, nil, c)
 
@@ -117,7 +124,7 @@ func TestSampleDelivery(t *testing.T) {
 
 func TestSampleDeliveryOrder(t *testing.T) {
 	ts := 10
-	n := defaultQueueManagerConfig.MaxSamplesPerSend * ts
+	n := config.DefaultQueueConfig.MaxSamplesPerSend * ts
 
 	samples := make(model.Samples, 0, n)
 	for i := 0; i < n; i++ {
@@ -133,7 +140,7 @@ func TestSampleDeliveryOrder(t *testing.T) {
 
 	c := NewTestStorageClient()
 	c.expectSamples(samples)
-	m := NewQueueManager(nil, defaultQueueManagerConfig, nil, nil, c)
+	m := NewQueueManager(nil, config.DefaultQueueConfig, nil, nil, c)
 
 	// These should be received by the client.
 	for _, s := range samples {
@@ -161,7 +168,7 @@ func NewTestBlockedStorageClient() *TestBlockingStorageClient {
 	}
 }
 
-func (c *TestBlockingStorageClient) Store(s model.Samples) error {
+func (c *TestBlockingStorageClient) Store(_ *prompb.WriteRequest) error {
 	atomic.AddUint64(&c.numCalls, 1)
 	<-c.block
 	return nil
@@ -194,7 +201,7 @@ func TestSpawnNotMoreThanMaxConcurrentSendsGoroutines(t *testing.T) {
 	// `MaxSamplesPerSend*Shards` samples should be consumed by the
 	// per-shard goroutines, and then another `MaxSamplesPerSend`
 	// should be left on the queue.
-	n := defaultQueueManagerConfig.MaxSamplesPerSend * 2
+	n := config.DefaultQueueConfig.MaxSamplesPerSend * 2
 
 	samples := make(model.Samples, 0, n)
 	for i := 0; i < n; i++ {
@@ -208,9 +215,9 @@ func TestSpawnNotMoreThanMaxConcurrentSendsGoroutines(t *testing.T) {
 	}
 
 	c := NewTestBlockedStorageClient()
-	cfg := defaultQueueManagerConfig
+	cfg := config.DefaultQueueConfig
 	cfg.MaxShards = 1
-	cfg.QueueCapacity = n
+	cfg.Capacity = n
 	m := NewQueueManager(nil, cfg, nil, nil, c)
 
 	m.Start()
@@ -240,7 +247,7 @@ func TestSpawnNotMoreThanMaxConcurrentSendsGoroutines(t *testing.T) {
 		time.Sleep(10 * time.Millisecond)
 	}
 
-	if m.queueLen() != defaultQueueManagerConfig.MaxSamplesPerSend {
+	if m.queueLen() != config.DefaultQueueConfig.MaxSamplesPerSend {
 		t.Fatalf("Failed to drain QueueManager queue, %d elements left",
 			m.queueLen(),
 		)

storage/remote/read.go

@@ -15,17 +15,14 @@ package remote
 
 import (
 	"context"
-	"sort"
 
 	"github.com/prometheus/common/model"
-
 	"github.com/prometheus/prometheus/pkg/labels"
-	"github.com/prometheus/prometheus/prompb"
 	"github.com/prometheus/prometheus/storage"
 )
 
 // Querier returns a new Querier on the storage.
-func (r *Storage) Querier(_ context.Context, mint, maxt int64) (storage.Querier, error) {
+func (r *Storage) Querier(ctx context.Context, mint, maxt int64) (storage.Querier, error) {
 	r.mtx.Lock()
 	defer r.mtx.Unlock()
 
@@ -47,6 +44,7 @@ func (r *Storage) Querier(_ context.Context, mint, maxt int64) (storage.Querier,
 			}
 		}
 		queriers = append(queriers, &querier{
+			ctx:            ctx,
 			mint:           mint,
 			maxt:           cmaxt,
 			client:         c,
@@ -61,6 +59,7 @@ var newMergeQueriers = storage.NewMergeQuerier
 
 // Querier is an adapter to make a Client usable as a storage.Querier.
 type querier struct {
+	ctx            context.Context
 	mint, maxt     int64
 	client         *Client
 	externalLabels model.LabelSet
@@ -70,61 +69,19 @@ type querier struct {
 func (q *querier) Select(matchers ...*labels.Matcher) storage.SeriesSet {
 	m, added := q.addExternalLabels(matchers)
 
-	res, err := q.client.Read(context.TODO(), q.mint, q.maxt, labelMatchersToProto(m))
+	query, err := ToQuery(q.mint, q.maxt, m)
 	if err != nil {
 		return errSeriesSet{err: err}
 	}
 
-	series := make([]storage.Series, 0, len(res))
-	for _, ts := range res {
-		labels := labelPairsToLabels(ts.Labels)
-		removeLabels(&labels, added)
-		series = append(series, &concreteSeries{
-			labels:  labels,
-			samples: ts.Samples,
-		})
+	res, err := q.client.Read(q.ctx, query)
+	if err != nil {
+		return errSeriesSet{err: err}
 	}
-	sort.Sort(byLabel(series))
-	return &concreteSeriesSet{
-		series: series,
-	}
-}
 
-func labelMatchersToProto(matchers []*labels.Matcher) []*prompb.LabelMatcher {
-	pbMatchers := make([]*prompb.LabelMatcher, 0, len(matchers))
-	for _, m := range matchers {
-		var mType prompb.LabelMatcher_Type
-		switch m.Type {
-		case labels.MatchEqual:
-			mType = prompb.LabelMatcher_EQ
-		case labels.MatchNotEqual:
-			mType = prompb.LabelMatcher_NEQ
-		case labels.MatchRegexp:
-			mType = prompb.LabelMatcher_RE
-		case labels.MatchNotRegexp:
-			mType = prompb.LabelMatcher_NRE
-		default:
-			panic("invalid matcher type")
-		}
-		pbMatchers = append(pbMatchers, &prompb.LabelMatcher{
-			Type:  mType,
-			Name:  string(m.Name),
-			Value: string(m.Value),
-		})
-	}
-	return pbMatchers
-}
+	seriesSet := FromQueryResult(res)
 
-func labelPairsToLabels(labelPairs []*prompb.Label) labels.Labels {
-	result := make(labels.Labels, 0, len(labelPairs))
-	for _, l := range labelPairs {
-		result = append(result, labels.Label{
-			Name:  l.Name,
-			Value: l.Value,
-		})
-	}
-	sort.Sort(result)
-	return result
+	return newSeriesSetFilter(seriesSet, added)
 }
 
 type byLabel []storage.Series
@@ -144,94 +101,6 @@ func (q *querier) Close() error {
 	return nil
 }
 
-// errSeriesSet implements storage.SeriesSet, just returning an error.
-type errSeriesSet struct {
-	err error
-}
-
-func (errSeriesSet) Next() bool {
-	return false
-}
-
-func (errSeriesSet) At() storage.Series {
-	return nil
-}
-
-func (e errSeriesSet) Err() error {
-	return e.err
-}
-
-// concreteSeriesSet implements storage.SeriesSet.
-type concreteSeriesSet struct {
-	cur    int
-	series []storage.Series
-}
-
-func (c *concreteSeriesSet) Next() bool {
-	c.cur++
-	return c.cur-1 < len(c.series)
-}
-
-func (c *concreteSeriesSet) At() storage.Series {
-	return c.series[c.cur-1]
-}
-
-func (c *concreteSeriesSet) Err() error {
-	return nil
-}
-
-// concreteSeries implementes storage.Series.
-type concreteSeries struct {
-	labels  labels.Labels
-	samples []*prompb.Sample
-}
-
-func (c *concreteSeries) Labels() labels.Labels {
-	return c.labels
-}
-
-func (c *concreteSeries) Iterator() storage.SeriesIterator {
-	return newConcreteSeriersIterator(c)
-}
-
-// concreteSeriesIterator implements storage.SeriesIterator.
-type concreteSeriesIterator struct {
-	cur    int
-	series *concreteSeries
-}
-
-func newConcreteSeriersIterator(series *concreteSeries) storage.SeriesIterator {
-	return &concreteSeriesIterator{
-		cur:    -1,
-		series: series,
-	}
-}
-
-// Seek implements storage.SeriesIterator.
-func (c *concreteSeriesIterator) Seek(t int64) bool {
-	c.cur = sort.Search(len(c.series.samples), func(n int) bool {
-		return c.series.samples[n].Timestamp >= t
-	})
-	return c.cur < len(c.series.samples)
-}
-
-// At implements storage.SeriesIterator.
-func (c *concreteSeriesIterator) At() (t int64, v float64) {
-	s := c.series.samples[c.cur]
-	return s.Timestamp, s.Value
-}
-
-// Next implements storage.SeriesIterator.
-func (c *concreteSeriesIterator) Next() bool {
-	c.cur++
-	return c.cur < len(c.series.samples)
-}
-
-// Err implements storage.SeriesIterator.
-func (c *concreteSeriesIterator) Err() error {
-	return nil
-}
-
 // addExternalLabels adds matchers for each external label. External labels
 // that already have a corresponding user-supplied matcher are skipped, as we
 // assume that the user explicitly wants to select a different value for them.
@@ -258,12 +127,38 @@ func (q *querier) addExternalLabels(matchers []*labels.Matcher) ([]*labels.Match
 	return matchers, el
 }
 
-func removeLabels(l *labels.Labels, toDelete model.LabelSet) {
-	for i := 0; i < len(*l); {
-		if _, ok := toDelete[model.LabelName((*l)[i].Name)]; ok {
-			*l = (*l)[:i+copy((*l)[i:], (*l)[i+1:])]
-		} else {
-			i++
-		}
+func newSeriesSetFilter(ss storage.SeriesSet, toFilter model.LabelSet) storage.SeriesSet {
+	return &seriesSetFilter{
+		SeriesSet: ss,
+		toFilter:  toFilter,
 	}
 }
+
+type seriesSetFilter struct {
+	storage.SeriesSet
+	toFilter model.LabelSet
+}
+
+func (ssf seriesSetFilter) At() storage.Series {
+	return seriesFilter{
+		Series:   ssf.SeriesSet.At(),
+		toFilter: ssf.toFilter,
+	}
+}
+
+type seriesFilter struct {
+	storage.Series
+	toFilter model.LabelSet
+}
+
+func (sf seriesFilter) Labels() labels.Labels {
+	labels := sf.Series.Labels()
+	for i := 0; i < len(labels); {
+		if _, ok := sf.toFilter[model.LabelName(labels[i].Name)]; ok {
+			labels = labels[:i+copy(labels[i:], labels[i+1:])]
+			continue
+		}
+		i++
+	}
+	return labels
+}

storage/remote/read_test.go

@@ -98,55 +98,38 @@ func TestAddExternalLabels(t *testing.T) {
 	}
 }
 
-func TestRemoveLabels(t *testing.T) {
+func TestSeriesSetFilter(t *testing.T) {
 	tests := []struct {
-		in       labels.Labels
-		out      labels.Labels
+		in       *prompb.QueryResult
 		toRemove model.LabelSet
+
+		expected *prompb.QueryResult
 	}{
 		{
 			toRemove: model.LabelSet{"foo": "bar"},
-			in:       labels.FromStrings("foo", "bar", "a", "b"),
-			out:      labels.FromStrings("a", "b"),
+			in: &prompb.QueryResult{
+				Timeseries: []*prompb.TimeSeries{
+					{Labels: labelsToLabelsProto(labels.FromStrings("foo", "bar", "a", "b")), Samples: []*prompb.Sample{}},
+				},
+			},
+			expected: &prompb.QueryResult{
+				Timeseries: []*prompb.TimeSeries{
+					{Labels: labelsToLabelsProto(labels.FromStrings("a", "b")), Samples: []*prompb.Sample{}},
+				},
+			},
 		},
 	}
 
-	for i, test := range tests {
-		in := test.in.Copy()
-		removeLabels(&in, test.toRemove)
-
-		if !reflect.DeepEqual(in, test.out) {
-			t.Fatalf("%d. unexpected labels; want %v, got %v", i, test.out, in)
+	for i, tc := range tests {
+		filtered := newSeriesSetFilter(FromQueryResult(tc.in), tc.toRemove)
+		have, err := ToQueryResult(filtered)
+		if err != nil {
+			t.Fatal(err)
 		}
-	}
-}
 
-func TestConcreteSeriesSet(t *testing.T) {
-	series1 := &concreteSeries{
-		labels:  labels.FromStrings("foo", "bar"),
-		samples: []*prompb.Sample{&prompb.Sample{Value: 1, Timestamp: 2}},
-	}
-	series2 := &concreteSeries{
-		labels:  labels.FromStrings("foo", "baz"),
-		samples: []*prompb.Sample{&prompb.Sample{Value: 3, Timestamp: 4}},
-	}
-	c := &concreteSeriesSet{
-		series: []storage.Series{series1, series2},
-	}
-	if !c.Next() {
-		t.Fatalf("Expected Next() to be true.")
-	}
-	if c.At() != series1 {
-		t.Fatalf("Unexpected series returned.")
-	}
-	if !c.Next() {
-		t.Fatalf("Expected Next() to be true.")
-	}
-	if c.At() != series2 {
-		t.Fatalf("Unexpected series returned.")
-	}
-	if c.Next() {
-		t.Fatalf("Expected Next() to be false.")
+		if !reflect.DeepEqual(have, tc.expected) {
+			t.Fatalf("%d. unexpected labels; want %v, got %v", i, tc.expected, have)
+		}
 	}
 }
 
@@ -184,11 +167,11 @@ func TestRemoteStorageQuerier(t *testing.T) {
 		s := NewStorage(nil, func() (int64, error) { return test.localStartTime, nil })
 		s.clients = []*Client{}
 		for _, readRecent := range test.readRecentClients {
-			c, _ := NewClient(0, &clientConfig{
-				url:              nil,
-				timeout:          model.Duration(30 * time.Second),
-				httpClientConfig: config.HTTPClientConfig{},
-				readRecent:       readRecent,
+			c, _ := NewClient(0, &ClientConfig{
+				URL:              nil,
+				Timeout:          model.Duration(30 * time.Second),
+				HTTPClientConfig: config.HTTPClientConfig{},
+				ReadRecent:       readRecent,
 			})
 			s.clients = append(s.clients, c)
 		}

storage/remote/storage.go

@@ -58,17 +58,17 @@ func (s *Storage) ApplyConfig(conf *config.Config) error {
 	// TODO: we should only stop & recreate queues which have changes,
 	// as this can be quite disruptive.
 	for i, rwConf := range conf.RemoteWriteConfigs {
-		c, err := NewClient(i, &clientConfig{
-			url:              rwConf.URL,
-			timeout:          rwConf.RemoteTimeout,
-			httpClientConfig: rwConf.HTTPClientConfig,
+		c, err := NewClient(i, &ClientConfig{
+			URL:              rwConf.URL,
+			Timeout:          rwConf.RemoteTimeout,
+			HTTPClientConfig: rwConf.HTTPClientConfig,
 		})
 		if err != nil {
 			return err
 		}
 		newQueues = append(newQueues, NewQueueManager(
 			s.logger,
-			defaultQueueManagerConfig,
+			config.DefaultQueueConfig,
 			conf.GlobalConfig.ExternalLabels,
 			rwConf.WriteRelabelConfigs,
 			c,
@@ -88,11 +88,11 @@ func (s *Storage) ApplyConfig(conf *config.Config) error {
 
 	clients := []*Client{}
 	for i, rrConf := range conf.RemoteReadConfigs {
-		c, err := NewClient(i, &clientConfig{
-			url:              rrConf.URL,
-			timeout:          rrConf.RemoteTimeout,
-			httpClientConfig: rrConf.HTTPClientConfig,
-			readRecent:       rrConf.ReadRecent,
+		c, err := NewClient(i, &ClientConfig{
+			URL:              rrConf.URL,
+			Timeout:          rrConf.RemoteTimeout,
+			HTTPClientConfig: rrConf.HTTPClientConfig,
+			ReadRecent:       rrConf.ReadRecent,
 		})
 		if err != nil {
 			return err

storage/remote/write.go

@@ -38,14 +38,6 @@ func (s *Storage) Add(l labels.Labels, t int64, v float64) (uint64, error) {
 	return 0, nil
 }
 
-func labelsToMetric(ls labels.Labels) model.Metric {
-	metric := make(model.Metric, len(ls))
-	for _, l := range ls {
-		metric[model.LabelName(l.Name)] = model.LabelValue(l.Value)
-	}
-	return metric
-}
-
 // AddFast implements storage.Appender.
 func (s *Storage) AddFast(l labels.Labels, _ uint64, t int64, v float64) error {
 	_, err := s.Add(l, t, v)

web/api/v1/api.go

@@ -21,6 +21,7 @@ import (
 	"math"
 	"net/http"
 	"net/url"
+	"sort"
 	"strconv"
 	"time"
 
@@ -31,9 +32,11 @@ import (
 	"github.com/prometheus/prometheus/config"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/pkg/timestamp"
+	"github.com/prometheus/prometheus/prompb"
 	"github.com/prometheus/prometheus/promql"
 	"github.com/prometheus/prometheus/retrieval"
 	"github.com/prometheus/prometheus/storage"
+	"github.com/prometheus/prometheus/storage/remote"
 	"github.com/prometheus/prometheus/util/httputil"
 )
 
@@ -161,6 +164,7 @@ func (api *API) Register(r *route.Router) {
 	r.Get("/alertmanagers", instr("alertmanagers", api.alertmanagers))
 
 	r.Get("/status/config", instr("config", api.serveConfig))
+	r.Post("/read", api.ready(prometheus.InstrumentHandler("read", http.HandlerFunc(api.remoteRead))))
 }
 
 type queryData struct {
@@ -451,6 +455,105 @@ func (api *API) serveConfig(r *http.Request) (interface{}, *apiError) {
 	return cfg, nil
 }
 
+func (api *API) remoteRead(w http.ResponseWriter, r *http.Request) {
+	req, err := remote.DecodeReadRequest(r)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	resp := prompb.ReadResponse{
+		Results: make([]*prompb.QueryResult, len(req.Queries)),
+	}
+	for i, query := range req.Queries {
+		from, through, matchers, err := remote.FromQuery(query)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		querier, err := api.Queryable.Querier(r.Context(), from, through)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		defer querier.Close()
+
+		// Change equality matchers which match external labels
+		// to a matcher that looks for an empty label,
+		// as that label should not be present in the storage.
+		externalLabels := api.config().GlobalConfig.ExternalLabels.Clone()
+		filteredMatchers := make([]*labels.Matcher, 0, len(matchers))
+		for _, m := range matchers {
+			value := externalLabels[model.LabelName(m.Name)]
+			if m.Type == labels.MatchEqual && value == model.LabelValue(m.Value) {
+				matcher, err := labels.NewMatcher(labels.MatchEqual, m.Name, "")
+				if err != nil {
+					http.Error(w, err.Error(), http.StatusInternalServerError)
+					return
+				}
+				filteredMatchers = append(filteredMatchers, matcher)
+			} else {
+				filteredMatchers = append(filteredMatchers, m)
+			}
+		}
+
+		resp.Results[i], err = remote.ToQueryResult(querier.Select(filteredMatchers...))
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		// Add external labels back in, in sorted order.
+		sortedExternalLabels := make([]*prompb.Label, 0, len(externalLabels))
+		for name, value := range externalLabels {
+			sortedExternalLabels = append(sortedExternalLabels, &prompb.Label{
+				Name:  string(name),
+				Value: string(value),
+			})
+		}
+		sort.Slice(sortedExternalLabels, func(i, j int) bool {
+			return sortedExternalLabels[i].Name < sortedExternalLabels[j].Name
+		})
+
+		for _, ts := range resp.Results[i].Timeseries {
+			ts.Labels = mergeLabels(ts.Labels, sortedExternalLabels)
+		}
+	}
+
+	if err := remote.EncodeReadResponse(&resp, w); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+}
+
+// mergeLabels merges two sets of sorted proto labels, preferring those in
+// primary to those in secondary when there is an overlap.
+func mergeLabels(primary, secondary []*prompb.Label) []*prompb.Label {
+	result := make([]*prompb.Label, 0, len(primary)+len(secondary))
+	i, j := 0, 0
+	for i < len(primary) && j < len(secondary) {
+		if primary[i].Name < secondary[j].Name {
+			result = append(result, primary[i])
+			i++
+		} else if primary[i].Name > secondary[j].Name {
+			result = append(result, secondary[j])
+			j++
+		} else {
+			result = append(result, primary[i])
+			i++
+			j++
+		}
+	}
+	for ; i < len(primary); i++ {
+		result = append(result, primary[i])
+	}
+	for ; j < len(secondary); j++ {
+		result = append(result, secondary[j])
+	}
+	return result
+}
+
 func respond(w http.ResponseWriter, data interface{}) {
 	w.Header().Set("Content-Type", "application/json")
 	w.WriteHeader(http.StatusOK)

web/api/v1/api_test.go

@@ -14,6 +14,7 @@
 package v1
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"errors"
@@ -26,14 +27,18 @@ import (
 	"testing"
 	"time"
 
+	"github.com/gogo/protobuf/proto"
+	"github.com/golang/snappy"
 	"github.com/prometheus/common/model"
 	"github.com/prometheus/common/route"
 
 	"github.com/prometheus/prometheus/config"
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/pkg/timestamp"
+	"github.com/prometheus/prometheus/prompb"
 	"github.com/prometheus/prometheus/promql"
 	"github.com/prometheus/prometheus/retrieval"
+	"github.com/prometheus/prometheus/storage/remote"
 )
 
 type targetRetrieverFunc func() []*retrieval.Target
@@ -476,6 +481,102 @@ func TestEndpoints(t *testing.T) {
 	}
 }
 
+func TestReadEndpoint(t *testing.T) {
+	suite, err := promql.NewTest(t, `
+		load 1m
+			test_metric1{foo="bar",baz="qux"} 1
+	`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer suite.Close()
+
+	if err := suite.Run(); err != nil {
+		t.Fatal(err)
+	}
+
+	api := &API{
+		Queryable:   suite.Storage(),
+		QueryEngine: suite.QueryEngine(),
+		config: func() config.Config {
+			return config.Config{
+				GlobalConfig: config.GlobalConfig{
+					ExternalLabels: model.LabelSet{
+						"baz": "a",
+						"b":   "c",
+						"d":   "e",
+					},
+				},
+			}
+		},
+	}
+
+	// Encode the request.
+	matcher1, err := labels.NewMatcher(labels.MatchEqual, "__name__", "test_metric1")
+	if err != nil {
+		t.Fatal(err)
+	}
+	matcher2, err := labels.NewMatcher(labels.MatchEqual, "d", "e")
+	if err != nil {
+		t.Fatal(err)
+	}
+	query, err := remote.ToQuery(0, 1, []*labels.Matcher{matcher1, matcher2})
+	if err != nil {
+		t.Fatal(err)
+	}
+	req := &prompb.ReadRequest{Queries: []*prompb.Query{query}}
+	data, err := proto.Marshal(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	compressed := snappy.Encode(nil, data)
+	request, err := http.NewRequest("POST", "", bytes.NewBuffer(compressed))
+	if err != nil {
+		t.Fatal(err)
+	}
+	recorder := httptest.NewRecorder()
+	api.remoteRead(recorder, request)
+
+	// Decode the response.
+	compressed, err = ioutil.ReadAll(recorder.Result().Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	uncompressed, err := snappy.Decode(nil, compressed)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var resp prompb.ReadResponse
+	err = proto.Unmarshal(uncompressed, &resp)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(resp.Results) != 1 {
+		t.Fatalf("Expected 1 result, got %d", len(resp.Results))
+	}
+
+	result := resp.Results[0]
+	expected := &prompb.QueryResult{
+		Timeseries: []*prompb.TimeSeries{
+			{
+				Labels: []*prompb.Label{
+					{Name: "__name__", Value: "test_metric1"},
+					{Name: "b", Value: "c"},
+					{Name: "baz", Value: "qux"},
+					{Name: "d", Value: "e"},
+					{Name: "foo", Value: "bar"},
+				},
+				Samples: []*prompb.Sample{{Value: 1, Timestamp: 0}},
+			},
+		},
+	}
+	if !reflect.DeepEqual(result, expected) {
+		t.Fatalf("Expected response \n%v\n but got \n%v\n", result, expected)
+	}
+}
+
 func TestRespondSuccess(t *testing.T) {
 	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		respond(w, "test")