Support series query in query-frontend (#2123)

pkg/querier/queryrange/codec.go

@@ -58,59 +58,125 @@ func (r *LokiRequest) WithShards(shards logql.Shards) *LokiRequest {
 	return &new
 }
 
+func (r *LokiSeriesRequest) GetEnd() int64 {
+	return r.EndTs.UnixNano() / (int64(time.Millisecond) / int64(time.Nanosecond))
+}
+
+func (r *LokiSeriesRequest) GetStart() int64 {
+	return r.StartTs.UnixNano() / (int64(time.Millisecond) / int64(time.Nanosecond))
+}
+
+func (r *LokiSeriesRequest) WithStartEnd(s int64, e int64) queryrange.Request {
+	new := *r
+	new.StartTs = time.Unix(0, s*int64(time.Millisecond))
+	new.EndTs = time.Unix(0, e*int64(time.Millisecond))
+	return &new
+}
+
+func (r *LokiSeriesRequest) WithQuery(query string) queryrange.Request {
+	new := *r
+	return &new
+}
+
+func (r *LokiSeriesRequest) GetQuery() string {
+	return ""
+}
+
+func (r *LokiSeriesRequest) GetStep() int64 {
+	return 0
+}
+
 func (codec) DecodeRequest(_ context.Context, r *http.Request) (queryrange.Request, error) {
 	if err := r.ParseForm(); err != nil {
 		return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
 	}
-	req, err := loghttp.ParseRangeQuery(r)
+
-	if err != nil {
+	switch op := getOperation(r); op {
-		return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
+	case "query_range":
+		req, err := loghttp.ParseRangeQuery(r)
+		if err != nil {
+			return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
+		}
+		return &LokiRequest{
+			Query:     req.Query,
+			Limit:     req.Limit,
+			Direction: req.Direction,
+			StartTs:   req.Start.UTC(),
+			EndTs:     req.End.UTC(),
+			// GetStep must return milliseconds
+			Step:   int64(req.Step) / 1e6,
+			Path:   r.URL.Path,
+			Shards: req.Shards,
+		}, nil
+	case "series":
+		req, err := loghttp.ParseSeriesQuery(r)
+		if err != nil {
+			return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
+		}
+		return &LokiSeriesRequest{
+			Match:   req.Groups,
+			StartTs: req.Start.UTC(),
+			EndTs:   req.End.UTC(),
+			Path:    r.URL.Path,
+		}, nil
+	default:
+		return nil, httpgrpc.Errorf(http.StatusBadRequest, fmt.Sprintf("unknown request path: %s", r.URL.Path))
 	}
-	return &LokiRequest{
+
-		Query:     req.Query,
-		Limit:     req.Limit,
-		Direction: req.Direction,
-		StartTs:   req.Start.UTC(),
-		EndTs:     req.End.UTC(),
-		// GetStep must return milliseconds
-		Step:   int64(req.Step) / 1e6,
-		Path:   r.URL.Path,
-		Shards: req.Shards,
-	}, nil
 }
 
 func (codec) EncodeRequest(ctx context.Context, r queryrange.Request) (*http.Request, error) {
-	lokiReq, ok := r.(*LokiRequest)
+	switch request := r.(type) {
-	if !ok {
+	case *LokiRequest:
+		params := url.Values{
+			"start":     []string{fmt.Sprintf("%d", request.StartTs.UnixNano())},
+			"end":       []string{fmt.Sprintf("%d", request.EndTs.UnixNano())},
+			"query":     []string{request.Query},
+			"direction": []string{request.Direction.String()},
+			"limit":     []string{fmt.Sprintf("%d", request.Limit)},
+		}
+		if len(request.Shards) > 0 {
+			params["shards"] = request.Shards
+		}
+		if request.Step != 0 {
+			params["step"] = []string{fmt.Sprintf("%f", float64(request.Step)/float64(1e3))}
+		}
+		u := &url.URL{
+			// the request could come /api/prom/query but we want to only use the new api.
+			Path:     "/loki/api/v1/query_range",
+			RawQuery: params.Encode(),
+		}
+		req := &http.Request{
+			Method:     "GET",
+			RequestURI: u.String(), // This is what the httpgrpc code looks at.
+			URL:        u,
+			Body:       http.NoBody,
+			Header:     http.Header{},
+		}
+
+		return req.WithContext(ctx), nil
+	case *LokiSeriesRequest:
+		params := url.Values{
+			"start":   []string{fmt.Sprintf("%d", request.StartTs.UnixNano())},
+			"end":     []string{fmt.Sprintf("%d", request.EndTs.UnixNano())},
+			"match[]": request.Match,
+		}
+
+		u := &url.URL{
+			Path:     "/loki/api/v1/series",
+			RawQuery: params.Encode(),
+		}
+		req := &http.Request{
+			Method:     "GET",
+			RequestURI: u.String(), // This is what the httpgrpc code looks at.
+			URL:        u,
+			Body:       http.NoBody,
+			Header:     http.Header{},
+		}
+		return req.WithContext(ctx), nil
+	default:
 		return nil, httpgrpc.Errorf(http.StatusInternalServerError, "invalid request format")
 	}
-	params := url.Values{
-		"start":     []string{fmt.Sprintf("%d", lokiReq.StartTs.UnixNano())},
-		"end":       []string{fmt.Sprintf("%d", lokiReq.EndTs.UnixNano())},
-		"query":     []string{lokiReq.Query},
-		"direction": []string{lokiReq.Direction.String()},
-		"limit":     []string{fmt.Sprintf("%d", lokiReq.Limit)},
-	}
-	if len(lokiReq.Shards) > 0 {
-		params["shards"] = lokiReq.Shards
-	}
-	if lokiReq.Step != 0 {
-		params["step"] = []string{fmt.Sprintf("%f", float64(lokiReq.Step)/float64(1e3))}
-	}
-	u := &url.URL{
-		// the request could come /api/prom/query but we want to only use the new api.
-		Path:     "/loki/api/v1/query_range",
-		RawQuery: params.Encode(),
-	}
-	req := &http.Request{
-		Method:     "GET",
-		RequestURI: u.String(), // This is what the httpgrpc code looks at.
-		URL:        u,
-		Body:       http.NoBody,
-		Header:     http.Header{},
-	}
-
-	return req.WithContext(ctx), nil
 }
 
 func (codec) DecodeResponse(ctx context.Context, r *http.Response, req queryrange.Request) (queryrange.Response, error) {
@@ -130,85 +196,129 @@ func (codec) DecodeResponse(ctx context.Context, r *http.Response, req queryrang
 
 	sp.LogFields(otlog.Int("bytes", len(buf)))
 
-	var resp loghttp.QueryResponse
+	switch req.(type) {
-	if err := json.Unmarshal(buf, &resp); err != nil {
+	case *LokiSeriesRequest:
-		return nil, httpgrpc.Errorf(http.StatusInternalServerError, "error decoding response: %v", err)
+		var resp loghttp.SeriesResponse
-	}
+		if err := json.Unmarshal(buf, &resp); err != nil {
-	switch string(resp.Data.ResultType) {
+			return nil, httpgrpc.Errorf(http.StatusInternalServerError, "error decoding response: %v", err)
-	case loghttp.ResultTypeMatrix:
+		}
-		return &LokiPromResponse{
+
-			Response: &queryrange.PrometheusResponse{
+		data := make([]logproto.SeriesIdentifier, 0, len(resp.Data))
-				Status: resp.Status,
+		for _, label := range resp.Data {
-				Data: queryrange.PrometheusData{
+			d := logproto.SeriesIdentifier{
-					ResultType: loghttp.ResultTypeMatrix,
+				Labels: label.Map(),
-					Result:     toProto(resp.Data.Result.(loghttp.Matrix)),
+			}
-				},
+			data = append(data, d)
-			},
+		}
-			Statistics: resp.Data.Statistics,
+
-		}, nil
+		return &LokiSeriesResponse{
-	case loghttp.ResultTypeStream:
+			Status:  resp.Status,
-		return &LokiResponse{
+			Version: uint32(loghttp.GetVersion(req.(*LokiSeriesRequest).Path)),
-			Status:     resp.Status,
+			Data:    data,
-			Direction:  req.(*LokiRequest).Direction,
-			Limit:      req.(*LokiRequest).Limit,
-			Version:    uint32(loghttp.GetVersion(req.(*LokiRequest).Path)),
-			Statistics: resp.Data.Statistics,
-			Data: LokiData{
-				ResultType: loghttp.ResultTypeStream,
-				Result:     resp.Data.Result.(loghttp.Streams).ToProto(),
-			},
 		}, nil
 	default:
-		return nil, httpgrpc.Errorf(http.StatusBadRequest, "unsupported response type")
+		var resp loghttp.QueryResponse
+		if err := json.Unmarshal(buf, &resp); err != nil {
+			return nil, httpgrpc.Errorf(http.StatusInternalServerError, "error decoding response: %v", err)
+		}
+		switch string(resp.Data.ResultType) {
+		case loghttp.ResultTypeMatrix:
+			return &LokiPromResponse{
+				Response: &queryrange.PrometheusResponse{
+					Status: resp.Status,
+					Data: queryrange.PrometheusData{
+						ResultType: loghttp.ResultTypeMatrix,
+						Result:     toProto(resp.Data.Result.(loghttp.Matrix)),
+					},
+				},
+				Statistics: resp.Data.Statistics,
+			}, nil
+		case loghttp.ResultTypeStream:
+			return &LokiResponse{
+				Status:     resp.Status,
+				Direction:  req.(*LokiRequest).Direction,
+				Limit:      req.(*LokiRequest).Limit,
+				Version:    uint32(loghttp.GetVersion(req.(*LokiRequest).Path)),
+				Statistics: resp.Data.Statistics,
+				Data: LokiData{
+					ResultType: loghttp.ResultTypeStream,
+					Result:     resp.Data.Result.(loghttp.Streams).ToProto(),
+				},
+			}, nil
+		default:
+			return nil, httpgrpc.Errorf(http.StatusBadRequest, "unsupported response type")
+		}
 	}
+
 }
 
 func (codec) EncodeResponse(ctx context.Context, res queryrange.Response) (*http.Response, error) {
 	sp, _ := opentracing.StartSpanFromContext(ctx, "codec.EncodeResponse")
 	defer sp.Finish()
 
-	if promRes, ok := res.(*LokiPromResponse); ok {
+	switch response := res.(type) {
-		return promRes.encode(ctx)
+	case *LokiPromResponse:
-	}
+		return response.encode(ctx)
+	case *LokiResponse:
+		streams := make([]logproto.Stream, len(response.Data.Result))
 
-	proto, ok := res.(*LokiResponse)
+		for i, stream := range response.Data.Result {
-	if !ok {
+			streams[i] = logproto.Stream{
-		return nil, httpgrpc.Errorf(http.StatusInternalServerError, "invalid response format")
+				Labels:  stream.Labels,
-	}
+				Entries: stream.Entries,
+			}
+		}
+		result := logql.Result{
+			Data:       logql.Streams(streams),
+			Statistics: response.Statistics,
+		}
+		var buf bytes.Buffer
+		if loghttp.Version(response.Version) == loghttp.VersionLegacy {
+			if err := marshal_legacy.WriteQueryResponseJSON(result, &buf); err != nil {
+				return nil, err
+			}
+		} else {
+			if err := marshal.WriteQueryResponseJSON(result, &buf); err != nil {
+				return nil, err
+			}
+		}
 
-	streams := make([]logproto.Stream, len(proto.Data.Result))
+		sp.LogFields(otlog.Int("bytes", buf.Len()))
 
-	for i, stream := range proto.Data.Result {
+		resp := http.Response{
-		streams[i] = logproto.Stream{
+			Header: http.Header{
-			Labels:  stream.Labels,
+				"Content-Type": []string{"application/json"},
-			Entries: stream.Entries,
+			},
+			Body:       ioutil.NopCloser(&buf),
+			StatusCode: http.StatusOK,
 		}
-	}
+		return &resp, nil
-	result := logql.Result{
+	case *LokiSeriesResponse:
-		Data:       logql.Streams(streams),
+		var data []loghttp.LabelSet
-		Statistics: proto.Statistics,
+		for _, series := range response.Data {
-	}
+			data = append(data, series.GetLabels())
-	var buf bytes.Buffer
-	if loghttp.Version(proto.Version) == loghttp.VersionLegacy {
-		if err := marshal_legacy.WriteQueryResponseJSON(result, &buf); err != nil {
-			return nil, err
 		}
-	} else {
+		result := logproto.SeriesResponse{
-		if err := marshal.WriteQueryResponseJSON(result, &buf); err != nil {
+			Series: response.Data,
+		}
+		var buf bytes.Buffer
+		if err := marshal.WriteSeriesResponseJSON(result, &buf); err != nil {
 			return nil, err
 		}
-	}
 
-	sp.LogFields(otlog.Int("bytes", buf.Len()))
+		sp.LogFields(otlog.Int("bytes", buf.Len()))
 
-	resp := http.Response{
+		resp := http.Response{
-		Header: http.Header{
+			Header: http.Header{
-			"Content-Type": []string{"application/json"},
+				"Content-Type": []string{"application/json"},
-		},
+			},
-		Body:       ioutil.NopCloser(&buf),
+			Body:       ioutil.NopCloser(&buf),
-		StatusCode: http.StatusOK,
+			StatusCode: http.StatusOK,
+		}
+		return &resp, nil
+	default:
+		return nil, httpgrpc.Errorf(http.StatusInternalServerError, "invalid response format")
 	}
-	return &resp, nil
 }
 
 func (codec) MergeResponse(responses ...queryrange.Response) (queryrange.Response, error) {
@@ -216,7 +326,9 @@ func (codec) MergeResponse(responses ...queryrange.Response) (queryrange.Respons
 		return nil, errors.New("merging responses requires at least one response")
 	}
 	var mergedStats stats.Result
-	if _, ok := responses[0].(*LokiPromResponse); ok {
+	switch responses[0].(type) {
+	case *LokiPromResponse:
+
 		promResponses := make([]queryrange.Response, 0, len(responses))
 		for _, res := range responses {
 			mergedStats.Merge(res.(*LokiPromResponse).Statistics)
@@ -230,32 +342,55 @@ func (codec) MergeResponse(responses ...queryrange.Response) (queryrange.Respons
 			Response:   promRes.(*queryrange.PrometheusResponse),
 			Statistics: mergedStats,
 		}, nil
-	}
+	case *LokiResponse:
-	lokiRes, ok := responses[0].(*LokiResponse)
+		lokiRes := responses[0].(*LokiResponse)
-	if !ok {
-		return nil, errors.New("unexpected response type while merging")
-	}
 
-	lokiResponses := make([]*LokiResponse, 0, len(responses))
+		lokiResponses := make([]*LokiResponse, 0, len(responses))
-	for _, res := range responses {
+		for _, res := range responses {
-		lokiResult := res.(*LokiResponse)
+			lokiResult := res.(*LokiResponse)
-		mergedStats.Merge(lokiResult.Statistics)
+			mergedStats.Merge(lokiResult.Statistics)
-		lokiResponses = append(lokiResponses, lokiResult)
+			lokiResponses = append(lokiResponses, lokiResult)
-	}
+		}
 
-	return &LokiResponse{
+		return &LokiResponse{
-		Status:     loghttp.QueryStatusSuccess,
+			Status:     loghttp.QueryStatusSuccess,
-		Direction:  lokiRes.Direction,
+			Direction:  lokiRes.Direction,
-		Limit:      lokiRes.Limit,
+			Limit:      lokiRes.Limit,
-		Version:    lokiRes.Version,
+			Version:    lokiRes.Version,
-		ErrorType:  lokiRes.ErrorType,
+			ErrorType:  lokiRes.ErrorType,
-		Error:      lokiRes.Error,
+			Error:      lokiRes.Error,
-		Statistics: mergedStats,
+			Statistics: mergedStats,
-		Data: LokiData{
+			Data: LokiData{
-			ResultType: loghttp.ResultTypeStream,
+				ResultType: loghttp.ResultTypeStream,
-			Result:     mergeOrderedNonOverlappingStreams(lokiResponses, lokiRes.Limit, lokiRes.Direction),
+				Result:     mergeOrderedNonOverlappingStreams(lokiResponses, lokiRes.Limit, lokiRes.Direction),
-		},
+			},
-	}, nil
+		}, nil
+	case *LokiSeriesResponse:
+		lokiSeriesRes := responses[0].(*LokiSeriesResponse)
+
+		var lokiSeriesData []logproto.SeriesIdentifier
+		uniqueSeries := make(map[string]struct{})
+
+		// only unique series should be merged
+		for _, res := range responses {
+			lokiResult := res.(*LokiSeriesResponse)
+			for _, series := range lokiResult.Data {
+				if _, ok := uniqueSeries[series.String()]; !ok {
+					lokiSeriesData = append(lokiSeriesData, series)
+					uniqueSeries[series.String()] = struct{}{}
+				}
+
+			}
+		}
+
+		return &LokiSeriesResponse{
+			Status:  lokiSeriesRes.Status,
+			Version: lokiSeriesRes.Version,
+			Data:    lokiSeriesData,
+		}, nil
+	default:
+		return nil, errors.New("unknown response in merging responses")
+	}
 }
 
 // mergeOrderedNonOverlappingStreams merges a set of ordered, nonoverlapping responses by concatenating matching streams then running them through a heap to pull out limit values

pkg/querier/queryrange/codec_test.go

@@ -48,6 +48,15 @@ func Test_codec_DecodeRequest(t *testing.T) {
 			StartTs:   start,
 			EndTs:     end,
 		}, false},
+		{"series", func() (*http.Request, error) {
+			return http.NewRequest(http.MethodGet,
+				fmt.Sprintf(`/series?start=%d&end=%d&match={foo="bar"}`, start.UnixNano(), end.UnixNano()), nil)
+		}, &LokiSeriesRequest{
+			Match:   []string{`{foo="bar"}`},
+			Path:    "/series",
+			StartTs: start,
+			EndTs:   end,
+		}, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -115,6 +124,13 @@ func Test_codec_DecodeResponse(t *testing.T) {
 				},
 				Statistics: statsResult,
 			}, false},
+		{"series", &http.Response{StatusCode: 200, Body: ioutil.NopCloser(strings.NewReader(seriesString))},
+			&LokiSeriesRequest{Path: "/loki/api/v1/series"},
+			&LokiSeriesResponse{
+				Status:  "success",
+				Version: uint32(loghttp.VersionV1),
+				Data:    seriesData,
+			}, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -168,6 +184,35 @@ func Test_codec_EncodeRequest(t *testing.T) {
 	require.Equal(t, "/loki/api/v1/query_range", req.(*LokiRequest).Path)
 }
 
+func Test_codec_series_EncodeRequest(t *testing.T) {
+	got, err := lokiCodec.EncodeRequest(context.TODO(), &queryrange.PrometheusRequest{})
+	require.Error(t, err)
+	require.Nil(t, got)
+
+	ctx := context.Background()
+	toEncode := &LokiSeriesRequest{
+		Match:   []string{`{foo="bar"}`},
+		Path:    "/series",
+		StartTs: start,
+		EndTs:   end,
+	}
+	got, err = lokiCodec.EncodeRequest(ctx, toEncode)
+	require.NoError(t, err)
+	require.Equal(t, ctx, got.Context())
+	require.Equal(t, "/loki/api/v1/series", got.URL.Path)
+	require.Equal(t, fmt.Sprintf("%d", start.UnixNano()), got.URL.Query().Get("start"))
+	require.Equal(t, fmt.Sprintf("%d", end.UnixNano()), got.URL.Query().Get("end"))
+	require.Equal(t, `{foo="bar"}`, got.URL.Query().Get("match[]"))
+
+	// testing a full roundtrip
+	req, err := lokiCodec.DecodeRequest(context.TODO(), got)
+	require.NoError(t, err)
+	require.Equal(t, toEncode.Match, req.(*LokiSeriesRequest).Match)
+	require.Equal(t, toEncode.StartTs, req.(*LokiSeriesRequest).StartTs)
+	require.Equal(t, toEncode.EndTs, req.(*LokiSeriesRequest).EndTs)
+	require.Equal(t, "/loki/api/v1/series", req.(*LokiSeriesRequest).Path)
+}
+
 func Test_codec_EncodeResponse(t *testing.T) {
 
 	tests := []struct {
@@ -211,6 +256,12 @@ func Test_codec_EncodeResponse(t *testing.T) {
 				},
 				Statistics: statsResult,
 			}, streamsStringLegacy, false},
+		{"loki series",
+			&LokiSeriesResponse{
+				Status:  "success",
+				Version: uint32(loghttp.VersionV1),
+				Data:    seriesData,
+			}, seriesString, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -604,6 +655,51 @@ func Test_codec_MergeResponse(t *testing.T) {
 			},
 			false,
 		},
+		{
+			"loki series",
+			[]queryrange.Response{
+				&LokiSeriesResponse{
+					Status:  "success",
+					Version: 1,
+					Data: []logproto.SeriesIdentifier{
+						{
+							Labels: map[string]string{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+						},
+						{
+							Labels: map[string]string{"filename": "/var/hostlog/test.log", "job": "varlogs"},
+						},
+					},
+				},
+				&LokiSeriesResponse{
+					Status:  "success",
+					Version: 1,
+					Data: []logproto.SeriesIdentifier{
+						{
+							Labels: map[string]string{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+						},
+						{
+							Labels: map[string]string{"filename": "/var/hostlog/other.log", "job": "varlogs"},
+						},
+					},
+				},
+			},
+			&LokiSeriesResponse{
+				Status:  "success",
+				Version: 1,
+				Data: []logproto.SeriesIdentifier{
+					{
+						Labels: map[string]string{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+					},
+					{
+						Labels: map[string]string{"filename": "/var/hostlog/test.log", "job": "varlogs"},
+					},
+					{
+						Labels: map[string]string{"filename": "/var/hostlog/other.log", "job": "varlogs"},
+					},
+				},
+			},
+			false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -756,6 +852,21 @@ var (
 			},
 		},
 	}
+	seriesString = `{
+		"status": "success",
+		"data": [
+			{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+			{"filename": "/var/hostlog/test.log", "job": "varlogs"}
+		]
+	}`
+	seriesData = []logproto.SeriesIdentifier{
+		{
+			Labels: map[string]string{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+		},
+		{
+			Labels: map[string]string{"filename": "/var/hostlog/test.log", "job": "varlogs"},
+		},
+	}
 	statsResult = stats.Result{
 		Summary: stats.Summary{
 			BytesProcessedPerSecond: 20,

pkg/querier/queryrange/queryrange.pb.go

@@ -230,6 +230,132 @@ func (m *LokiResponse) GetStatistics() stats.Result {
 	return stats.Result{}
 }
 
+type LokiSeriesRequest struct {
+	Match   []string  `protobuf:"bytes,1,rep,name=match,proto3" json:"match,omitempty"`
+	StartTs time.Time `protobuf:"bytes,2,opt,name=startTs,proto3,stdtime" json:"startTs"`
+	EndTs   time.Time `protobuf:"bytes,3,opt,name=endTs,proto3,stdtime" json:"endTs"`
+	Path    string    `protobuf:"bytes,4,opt,name=path,proto3" json:"path,omitempty"`
+}
+
+func (m *LokiSeriesRequest) Reset()      { *m = LokiSeriesRequest{} }
+func (*LokiSeriesRequest) ProtoMessage() {}
+func (*LokiSeriesRequest) Descriptor() ([]byte, []int) {
+	return fileDescriptor_51b9d53b40d11902, []int{2}
+}
+func (m *LokiSeriesRequest) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *LokiSeriesRequest) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_LokiSeriesRequest.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalTo(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *LokiSeriesRequest) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_LokiSeriesRequest.Merge(m, src)
+}
+func (m *LokiSeriesRequest) XXX_Size() int {
+	return m.Size()
+}
+func (m *LokiSeriesRequest) XXX_DiscardUnknown() {
+	xxx_messageInfo_LokiSeriesRequest.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_LokiSeriesRequest proto.InternalMessageInfo
+
+func (m *LokiSeriesRequest) GetMatch() []string {
+	if m != nil {
+		return m.Match
+	}
+	return nil
+}
+
+func (m *LokiSeriesRequest) GetStartTs() time.Time {
+	if m != nil {
+		return m.StartTs
+	}
+	return time.Time{}
+}
+
+func (m *LokiSeriesRequest) GetEndTs() time.Time {
+	if m != nil {
+		return m.EndTs
+	}
+	return time.Time{}
+}
+
+func (m *LokiSeriesRequest) GetPath() string {
+	if m != nil {
+		return m.Path
+	}
+	return ""
+}
+
+type LokiSeriesResponse struct {
+	Status  string                      `protobuf:"bytes,1,opt,name=Status,json=status,proto3" json:"status"`
+	Data    []logproto.SeriesIdentifier `protobuf:"bytes,2,rep,name=Data,json=data,proto3" json:"data,omitempty"`
+	Version uint32                      `protobuf:"varint,3,opt,name=version,proto3" json:"version,omitempty"`
+}
+
+func (m *LokiSeriesResponse) Reset()      { *m = LokiSeriesResponse{} }
+func (*LokiSeriesResponse) ProtoMessage() {}
+func (*LokiSeriesResponse) Descriptor() ([]byte, []int) {
+	return fileDescriptor_51b9d53b40d11902, []int{3}
+}
+func (m *LokiSeriesResponse) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *LokiSeriesResponse) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_LokiSeriesResponse.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalTo(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *LokiSeriesResponse) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_LokiSeriesResponse.Merge(m, src)
+}
+func (m *LokiSeriesResponse) XXX_Size() int {
+	return m.Size()
+}
+func (m *LokiSeriesResponse) XXX_DiscardUnknown() {
+	xxx_messageInfo_LokiSeriesResponse.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_LokiSeriesResponse proto.InternalMessageInfo
+
+func (m *LokiSeriesResponse) GetStatus() string {
+	if m != nil {
+		return m.Status
+	}
+	return ""
+}
+
+func (m *LokiSeriesResponse) GetData() []logproto.SeriesIdentifier {
+	if m != nil {
+		return m.Data
+	}
+	return nil
+}
+
+func (m *LokiSeriesResponse) GetVersion() uint32 {
+	if m != nil {
+		return m.Version
+	}
+	return 0
+}
+
 type LokiData struct {
 	ResultType string                                        `protobuf:"bytes,1,opt,name=ResultType,json=resultType,proto3" json:"resultType"`
 	Result     []github_com_grafana_loki_pkg_logproto.Stream `protobuf:"bytes,2,rep,name=Result,json=result,proto3,customtype=github.com/grafana/loki/pkg/logproto.Stream" json:"result"`
@@ -238,7 +364,7 @@ type LokiData struct {
 func (m *LokiData) Reset()      { *m = LokiData{} }
 func (*LokiData) ProtoMessage() {}
 func (*LokiData) Descriptor() ([]byte, []int) {
-	return fileDescriptor_51b9d53b40d11902, []int{2}
+	return fileDescriptor_51b9d53b40d11902, []int{4}
 }
 func (m *LokiData) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -283,7 +409,7 @@ type LokiPromResponse struct {
 func (m *LokiPromResponse) Reset()      { *m = LokiPromResponse{} }
 func (*LokiPromResponse) ProtoMessage() {}
 func (*LokiPromResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_51b9d53b40d11902, []int{3}
+	return fileDescriptor_51b9d53b40d11902, []int{5}
 }
 func (m *LokiPromResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -329,6 +455,8 @@ func (m *LokiPromResponse) GetStatistics() stats.Result {
 func init() {
 	proto.RegisterType((*LokiRequest)(nil), "queryrange.LokiRequest")
 	proto.RegisterType((*LokiResponse)(nil), "queryrange.LokiResponse")
+	proto.RegisterType((*LokiSeriesRequest)(nil), "queryrange.LokiSeriesRequest")
+	proto.RegisterType((*LokiSeriesResponse)(nil), "queryrange.LokiSeriesResponse")
 	proto.RegisterType((*LokiData)(nil), "queryrange.LokiData")
 	proto.RegisterType((*LokiPromResponse)(nil), "queryrange.LokiPromResponse")
 }
@@ -338,50 +466,55 @@ func init() {
 }
 
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+	0x9b, 0x57, 0xfc, 0x59, 0xf8, 0x91, 0x3f, 0x25, 0xc4, 0x32, 0x1d, 0xe9, 0xdf, 0x39, 0x3d, 0x77,
+	0xac, 0xb3, 0x73, 0xc7, 0xba, 0x3c, 0x77, 0xc0, 0xab, 0xb9, 0x03, 0xde, 0xce, 0x1d, 0x70, 0x32,
+	0x77, 0xc0, 0xe9, 0xdc, 0x01, 0x9f, 0xe7, 0x0e, 0xf8, 0x32, 0x77, 0xac, 0xcb, 0xb9, 0x03, 0x8e,
+	0x2f, 0x1c, 0xeb, 0xf4, 0xc2, 0xb1, 0xce, 0x2e, 0x1c, 0x6b, 0xaf, 0xa2, 0x5e, 0xb8, 0xf9, 0x2d,
+	0x00, 0x00, 0xff, 0xff, 0x93, 0x63, 0xfc, 0xe4, 0x8e, 0x06, 0x00, 0x00,
 }
 
 func (this *LokiRequest) Equal(that interface{}) bool {
@@ -479,6 +612,79 @@ func (this *LokiResponse) Equal(that interface{}) bool {
 	}
 	return true
 }
+func (this *LokiSeriesRequest) Equal(that interface{}) bool {
+	if that == nil {
+		return this == nil
+	}
+
+	that1, ok := that.(*LokiSeriesRequest)
+	if !ok {
+		that2, ok := that.(LokiSeriesRequest)
+		if ok {
+			that1 = &that2
+		} else {
+			return false
+		}
+	}
+	if that1 == nil {
+		return this == nil
+	} else if this == nil {
+		return false
+	}
+	if len(this.Match) != len(that1.Match) {
+		return false
+	}
+	for i := range this.Match {
+		if this.Match[i] != that1.Match[i] {
+			return false
+		}
+	}
+	if !this.StartTs.Equal(that1.StartTs) {
+		return false
+	}
+	if !this.EndTs.Equal(that1.EndTs) {
+		return false
+	}
+	if this.Path != that1.Path {
+		return false
+	}
+	return true
+}
+func (this *LokiSeriesResponse) Equal(that interface{}) bool {
+	if that == nil {
+		return this == nil
+	}
+
+	that1, ok := that.(*LokiSeriesResponse)
+	if !ok {
+		that2, ok := that.(LokiSeriesResponse)
+		if ok {
+			that1 = &that2
+		} else {
+			return false
+		}
+	}
+	if that1 == nil {
+		return this == nil
+	} else if this == nil {
+		return false
+	}
+	if this.Status != that1.Status {
+		return false
+	}
+	if len(this.Data) != len(that1.Data) {
+		return false
+	}
+	for i := range this.Data {
+		if !this.Data[i].Equal(&that1.Data[i]) {
+			return false
+		}
+	}
+	if this.Version != that1.Version {
+		return false
+	}
+	return true
+}
 func (this *LokiData) Equal(that interface{}) bool {
 	if that == nil {
 		return this == nil
@@ -572,6 +778,37 @@ func (this *LokiResponse) GoString() string {
 	s = append(s, "}")
 	return strings.Join(s, "")
 }
+func (this *LokiSeriesRequest) GoString() string {
+	if this == nil {
+		return "nil"
+	}
+	s := make([]string, 0, 8)
+	s = append(s, "&queryrange.LokiSeriesRequest{")
+	s = append(s, "Match: "+fmt.Sprintf("%#v", this.Match)+",\n")
+	s = append(s, "StartTs: "+fmt.Sprintf("%#v", this.StartTs)+",\n")
+	s = append(s, "EndTs: "+fmt.Sprintf("%#v", this.EndTs)+",\n")
+	s = append(s, "Path: "+fmt.Sprintf("%#v", this.Path)+",\n")
+	s = append(s, "}")
+	return strings.Join(s, "")
+}
+func (this *LokiSeriesResponse) GoString() string {
+	if this == nil {
+		return "nil"
+	}
+	s := make([]string, 0, 7)
+	s = append(s, "&queryrange.LokiSeriesResponse{")
+	s = append(s, "Status: "+fmt.Sprintf("%#v", this.Status)+",\n")
+	if this.Data != nil {
+		vs := make([]*logproto.SeriesIdentifier, len(this.Data))
+		for i := range vs {
+			vs[i] = &this.Data[i]
+		}
+		s = append(s, "Data: "+fmt.Sprintf("%#v", vs)+",\n")
+	}
+	s = append(s, "Version: "+fmt.Sprintf("%#v", this.Version)+",\n")
+	s = append(s, "}")
+	return strings.Join(s, "")
+}
 func (this *LokiData) GoString() string {
 	if this == nil {
 		return "nil"
@@ -747,6 +984,102 @@ func (m *LokiResponse) MarshalTo(dAtA []byte) (int, error) {
 	return i, nil
 }
 
+func (m *LokiSeriesRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LokiSeriesRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Match) > 0 {
+		for _, s := range m.Match {
+			dAtA[i] = 0xa
+			i++
+			l = len(s)
+			for l >= 1<<7 {
+				dAtA[i] = uint8(uint64(l)&0x7f | 0x80)
+				l >>= 7
+				i++
+			}
+			dAtA[i] = uint8(l)
+			i++
+			i += copy(dAtA[i:], s)
+		}
+	}
+	dAtA[i] = 0x12
+	i++
+	i = encodeVarintQueryrange(dAtA, i, uint64(github_com_gogo_protobuf_types.SizeOfStdTime(m.StartTs)))
+	n5, err := github_com_gogo_protobuf_types.StdTimeMarshalTo(m.StartTs, dAtA[i:])
+	if err != nil {
+		return 0, err
+	}
+	i += n5
+	dAtA[i] = 0x1a
+	i++
+	i = encodeVarintQueryrange(dAtA, i, uint64(github_com_gogo_protobuf_types.SizeOfStdTime(m.EndTs)))
+	n6, err := github_com_gogo_protobuf_types.StdTimeMarshalTo(m.EndTs, dAtA[i:])
+	if err != nil {
+		return 0, err
+	}
+	i += n6
+	if len(m.Path) > 0 {
+		dAtA[i] = 0x22
+		i++
+		i = encodeVarintQueryrange(dAtA, i, uint64(len(m.Path)))
+		i += copy(dAtA[i:], m.Path)
+	}
+	return i, nil
+}
+
+func (m *LokiSeriesResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LokiSeriesResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Status) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintQueryrange(dAtA, i, uint64(len(m.Status)))
+		i += copy(dAtA[i:], m.Status)
+	}
+	if len(m.Data) > 0 {
+		for _, msg := range m.Data {
+			dAtA[i] = 0x12
+			i++
+			i = encodeVarintQueryrange(dAtA, i, uint64(msg.Size()))
+			n, err := msg.MarshalTo(dAtA[i:])
+			if err != nil {
+				return 0, err
+			}
+			i += n
+		}
+	}
+	if m.Version != 0 {
+		dAtA[i] = 0x18
+		i++
+		i = encodeVarintQueryrange(dAtA, i, uint64(m.Version))
+	}
+	return i, nil
+}
+
 func (m *LokiData) Marshal() (dAtA []byte, err error) {
 	size := m.Size()
 	dAtA = make([]byte, size)
@@ -802,20 +1135,20 @@ func (m *LokiPromResponse) MarshalTo(dAtA []byte) (int, error) {
 		dAtA[i] = 0xa
 		i++
 		i = encodeVarintQueryrange(dAtA, i, uint64(m.Response.Size()))
-		n5, err := m.Response.MarshalTo(dAtA[i:])
+		n7, err := m.Response.MarshalTo(dAtA[i:])
 		if err != nil {
 			return 0, err
 		}
-		i += n5
+		i += n7
 	}
 	dAtA[i] = 0x12
 	i++
 	i = encodeVarintQueryrange(dAtA, i, uint64(m.Statistics.Size()))
-	n6, err := m.Statistics.MarshalTo(dAtA[i:])
+	n8, err := m.Statistics.MarshalTo(dAtA[i:])
 	if err != nil {
 		return 0, err
 	}
-	i += n6
+	i += n8
 	return i, nil
 }
 
@@ -898,16 +1231,61 @@ func (m *LokiResponse) Size() (n int) {
 	return n
 }
 
-func (m *LokiData) Size() (n int) {
+func (m *LokiSeriesRequest) Size() (n int) {
 	if m == nil {
 		return 0
 	}
 	var l int
 	_ = l
-	l = len(m.ResultType)
+	if len(m.Match) > 0 {
-	if l > 0 {
+		for _, s := range m.Match {
-		n += 1 + l + sovQueryrange(uint64(l))
+			l = len(s)
-	}
+			n += 1 + l + sovQueryrange(uint64(l))
+		}
+	}
+	l = github_com_gogo_protobuf_types.SizeOfStdTime(m.StartTs)
+	n += 1 + l + sovQueryrange(uint64(l))
+	l = github_com_gogo_protobuf_types.SizeOfStdTime(m.EndTs)
+	n += 1 + l + sovQueryrange(uint64(l))
+	l = len(m.Path)
+	if l > 0 {
+		n += 1 + l + sovQueryrange(uint64(l))
+	}
+	return n
+}
+
+func (m *LokiSeriesResponse) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.Status)
+	if l > 0 {
+		n += 1 + l + sovQueryrange(uint64(l))
+	}
+	if len(m.Data) > 0 {
+		for _, e := range m.Data {
+			l = e.Size()
+			n += 1 + l + sovQueryrange(uint64(l))
+		}
+	}
+	if m.Version != 0 {
+		n += 1 + sovQueryrange(uint64(m.Version))
+	}
+	return n
+}
+
+func (m *LokiData) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.ResultType)
+	if l > 0 {
+		n += 1 + l + sovQueryrange(uint64(l))
+	}
 	if len(m.Result) > 0 {
 		for _, e := range m.Result {
 			l = e.Size()
@@ -979,6 +1357,31 @@ func (this *LokiResponse) String() string {
 	}, "")
 	return s
 }
+func (this *LokiSeriesRequest) String() string {
+	if this == nil {
+		return "nil"
+	}
+	s := strings.Join([]string{`&LokiSeriesRequest{`,
+		`Match:` + fmt.Sprintf("%v", this.Match) + `,`,
+		`StartTs:` + strings.Replace(strings.Replace(this.StartTs.String(), "Timestamp", "types.Timestamp", 1), `&`, ``, 1) + `,`,
+		`EndTs:` + strings.Replace(strings.Replace(this.EndTs.String(), "Timestamp", "types.Timestamp", 1), `&`, ``, 1) + `,`,
+		`Path:` + fmt.Sprintf("%v", this.Path) + `,`,
+		`}`,
+	}, "")
+	return s
+}
+func (this *LokiSeriesResponse) String() string {
+	if this == nil {
+		return "nil"
+	}
+	s := strings.Join([]string{`&LokiSeriesResponse{`,
+		`Status:` + fmt.Sprintf("%v", this.Status) + `,`,
+		`Data:` + strings.Replace(strings.Replace(fmt.Sprintf("%v", this.Data), "SeriesIdentifier", "logproto.SeriesIdentifier", 1), `&`, ``, 1) + `,`,
+		`Version:` + fmt.Sprintf("%v", this.Version) + `,`,
+		`}`,
+	}, "")
+	return s
+}
 func (this *LokiData) String() string {
 	if this == nil {
 		return "nil"
@@ -1553,6 +1956,327 @@ func (m *LokiResponse) Unmarshal(dAtA []byte) error {
 	}
 	return nil
 }
+func (m *LokiSeriesRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowQueryrange
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LokiSeriesRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LokiSeriesRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Match", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowQueryrange
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Match = append(m.Match, string(dAtA[iNdEx:postIndex]))
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field StartTs", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowQueryrange
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			postIndex := iNdEx + msglen
+			if postIndex < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if err := github_com_gogo_protobuf_types.StdTimeUnmarshal(&m.StartTs, dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 3:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field EndTs", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowQueryrange
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			postIndex := iNdEx + msglen
+			if postIndex < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if err := github_com_gogo_protobuf_types.StdTimeUnmarshal(&m.EndTs, dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 4:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Path", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowQueryrange
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Path = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipQueryrange(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *LokiSeriesResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowQueryrange
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LokiSeriesResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LokiSeriesResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Status", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowQueryrange
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Status = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Data", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowQueryrange
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= int(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			postIndex := iNdEx + msglen
+			if postIndex < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Data = append(m.Data, logproto.SeriesIdentifier{})
+			if err := m.Data[len(m.Data)-1].Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Version", wireType)
+			}
+			m.Version = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowQueryrange
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Version |= uint32(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipQueryrange(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if (iNdEx + skippy) < 0 {
+				return ErrInvalidLengthQueryrange
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
 func (m *LokiData) Unmarshal(dAtA []byte) error {
 	l := len(dAtA)
 	iNdEx := 0

pkg/querier/queryrange/queryrange.proto

@@ -33,6 +33,19 @@ message LokiResponse {
   stats.Result statistics = 8 [(gogoproto.nullable) = false, (gogoproto.jsontag) = "statistics"];
 }
 
+message LokiSeriesRequest {
+  repeated string match = 1;
+  google.protobuf.Timestamp startTs = 2 [(gogoproto.stdtime) = true, (gogoproto.nullable) = false];
+  google.protobuf.Timestamp endTs = 3 [(gogoproto.stdtime) = true, (gogoproto.nullable) = false];
+  string path = 4;
+}
+
+message LokiSeriesResponse {
+  string Status = 1 [(gogoproto.jsontag) = "status"];
+  repeated logproto.SeriesIdentifier Data = 2 [(gogoproto.nullable) = false, (gogoproto.jsontag) = "data,omitempty"];
+  uint32 version = 3;
+}
+
 message LokiData {
   string ResultType = 1 [(gogoproto.jsontag) = "resultType"];
   repeated logproto.StreamAdapter Result = 2 [(gogoproto.nullable) = false, (gogoproto.jsontag) = "result", (gogoproto.customtype) = "github.com/grafana/loki/pkg/logproto.Stream"];

pkg/querier/queryrange/roundtrip.go

@@ -64,61 +64,77 @@ func NewTripperware(
 		return nil, nil, err
 	}
 
+	seriesTripperware, err := NewSeriesTripperware(cfg, log, limits, lokiCodec, instrumentMetrics, retryMetrics, splitByMetrics)
+	if err != nil {
+		return nil, nil, err
+	}
+
 	return func(next http.RoundTripper) http.RoundTripper {
 		metricRT := metricsTripperware(next)
 		logFilterRT := logFilterTripperware(next)
-		return newRoundTripper(next, logFilterRT, metricRT, limits)
+		seriesRT := seriesTripperware(next)
+		return newRoundTripper(next, logFilterRT, metricRT, seriesRT, limits)
 	}, cache, nil
 }
 
 type roundTripper struct {
-	next, log, metric http.RoundTripper
+	next, log, metric, series http.RoundTripper
 
 	limits Limits
 }
 
 // newRoundTripper creates a new queryrange roundtripper
-func newRoundTripper(next, log, metric http.RoundTripper, limits Limits) roundTripper {
+func newRoundTripper(next, log, metric, series http.RoundTripper, limits Limits) roundTripper {
 	return roundTripper{
 		log:    log,
 		limits: limits,
 		metric: metric,
+		series: series,
 		next:   next,
 	}
 }
 
 func (r roundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
-	if !strings.HasSuffix(req.URL.Path, "/query_range") && !strings.HasSuffix(req.URL.Path, "/prom/query") {
-		return r.next.RoundTrip(req)
-	}
 	err := req.ParseForm()
 	if err != nil {
 		return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
 	}
-	rangeQuery, err := loghttp.ParseRangeQuery(req)
+
-	if err != nil {
+	switch op := getOperation(req); op {
-		return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
+	case "query_range":
-	}
+		rangeQuery, err := loghttp.ParseRangeQuery(req)
-	expr, err := logql.ParseExpr(rangeQuery.Query)
-	if err != nil {
-		return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
-	}
-	switch e := expr.(type) {
-	case logql.SampleExpr:
-		return r.metric.RoundTrip(req)
-	case logql.LogSelectorExpr:
-		filter, err := transformRegexQuery(req, e).Filter()
 		if err != nil {
 			return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
 		}
-		if err := validateLimits(req, rangeQuery.Limit, r.limits); err != nil {
+		expr, err := logql.ParseExpr(rangeQuery.Query)
-			return nil, err
+		if err != nil {
+			return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
 		}
-		if filter == nil {
+		switch e := expr.(type) {
+		case logql.SampleExpr:
+			return r.metric.RoundTrip(req)
+		case logql.LogSelectorExpr:
+			filter, err := transformRegexQuery(req, e).Filter()
+			if err != nil {
+				return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
+			}
+			if err := validateLimits(req, rangeQuery.Limit, r.limits); err != nil {
+				return nil, err
+			}
+			if filter == nil {
+				return r.next.RoundTrip(req)
+			}
+			return r.log.RoundTrip(req)
+
+		default:
 			return r.next.RoundTrip(req)
 		}
-		return r.log.RoundTrip(req)
+	case "series":
-
+		_, err := loghttp.ParseSeriesQuery(req)
+		if err != nil {
+			return nil, httpgrpc.Errorf(http.StatusBadRequest, err.Error())
+		}
+		return r.series.RoundTrip(req)
 	default:
 		return r.next.RoundTrip(req)
 	}
@@ -154,6 +170,16 @@ func validateLimits(req *http.Request, reqLimit uint32, limits Limits) error {
 	return nil
 }
 
+func getOperation(req *http.Request) string {
+	if strings.HasSuffix(req.URL.Path, "/query_range") || strings.HasSuffix(req.URL.Path, "/prom/query") {
+		return "query_range"
+	} else if strings.HasSuffix(req.URL.Path, "/series") {
+		return "series"
+	} else {
+		return ""
+	}
+}
+
 // NewLogFilterTripperware creates a new frontend tripperware responsible for handling log requests with regex.
 func NewLogFilterTripperware(
 	cfg Config,
@@ -199,6 +225,32 @@ func NewLogFilterTripperware(
 	}, nil
 }
 
+// NewSeriesripperware creates a new frontend tripperware responsible for handling series requests
+func NewSeriesTripperware(
+	cfg Config,
+	log log.Logger,
+	limits Limits,
+	codec queryrange.Codec,
+	instrumentMetrics *queryrange.InstrumentMiddlewareMetrics,
+	retryMiddlewareMetrics *queryrange.RetryMiddlewareMetrics,
+	splitByMetrics *SplitByMetrics,
+) (frontend.Tripperware, error) {
+	queryRangeMiddleware := []queryrange.Middleware{}
+	if cfg.SplitQueriesByInterval != 0 {
+		queryRangeMiddleware = append(queryRangeMiddleware, queryrange.InstrumentMiddleware("split_by_interval", instrumentMetrics), SplitByIntervalMiddleware(limits, codec, splitByMetrics))
+	}
+	if cfg.MaxRetries > 0 {
+		queryRangeMiddleware = append(queryRangeMiddleware, queryrange.InstrumentMiddleware("retry", instrumentMetrics), queryrange.NewRetryMiddleware(log, cfg.MaxRetries, retryMiddlewareMetrics))
+	}
+
+	return func(next http.RoundTripper) http.RoundTripper {
+		if len(queryRangeMiddleware) > 0 {
+			return queryrange.NewRoundTripper(next, codec, queryRangeMiddleware...)
+		}
+		return next
+	}, nil
+}
+
 // NewMetricTripperware creates a new frontend tripperware responsible for handling metric queries
 func NewMetricTripperware(
 	cfg Config,

pkg/querier/queryrange/roundtrip_test.go

@@ -77,6 +77,17 @@ var (
 			Labels: `{filename="/var/hostlog/apport.log", job="varlogs"}`,
 		},
 	}
+
+	series = logproto.SeriesResponse{
+		Series: []logproto.SeriesIdentifier{
+			{
+				Labels: map[string]string{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+			},
+			{
+				Labels: map[string]string{"filename": "/var/hostlog/test.log", "job": "varlogs"},
+			},
+		},
+	}
 )
 
 // those tests are mostly for testing the glue between all component and make sure they activate correctly.
@@ -192,6 +203,47 @@ func TestLogFilterTripperware(t *testing.T) {
 	require.Error(t, err)
 }
 
+func TestSeriesTripperware(t *testing.T) {
+
+	tpw, stopper, err := NewTripperware(testConfig, util.Logger, fakeLimits{}, chunk.SchemaConfig{}, 0, nil)
+	if stopper != nil {
+		defer stopper.Stop()
+	}
+	require.NoError(t, err)
+	rt, err := newfakeRoundTripper()
+	require.NoError(t, err)
+	defer rt.Close()
+
+	lreq := &LokiSeriesRequest{
+		Match:   []string{`{job="varlogs"}`},
+		StartTs: testTime.Add(-6 * time.Hour), // bigger than the limit
+		EndTs:   testTime,
+		Path:    "/loki/api/v1/series",
+	}
+
+	ctx := user.InjectOrgID(context.Background(), "1")
+	req, err := lokiCodec.EncodeRequest(ctx, lreq)
+	require.NoError(t, err)
+
+	req = req.WithContext(ctx)
+	err = user.InjectOrgIDIntoHTTPRequest(ctx, req)
+	require.NoError(t, err)
+
+	count, h := seriesResult(series)
+	rt.setHandler(h)
+	resp, err := tpw(rt).RoundTrip(req)
+	// 2 queries
+	require.Equal(t, 2, *count)
+	require.NoError(t, err)
+	lokiSeriesResponse, err := lokiCodec.DecodeResponse(ctx, resp, lreq)
+	res, ok := lokiSeriesResponse.(*LokiSeriesResponse)
+	require.Equal(t, true, ok)
+
+	// make sure we return unique series since responses from
+	// SplitByInterval middleware might have duplicate series
+	require.Equal(t, series.Series, res.Data)
+	require.NoError(t, err)
+}
 func TestLogNoRegex(t *testing.T) {
 	tpw, stopper, err := NewTripperware(testConfig, util.Logger, fakeLimits{}, chunk.SchemaConfig{}, 0, nil)
 	if stopper != nil {
@@ -316,6 +368,10 @@ func TestPostQueries(t *testing.T) {
 			t.Error("unexpected metric roundtripper called")
 			return nil, nil
 		}),
+		frontend.RoundTripFunc(func(*http.Request) (*http.Response, error) {
+			t.Error("unexpected series roundtripper called")
+			return nil, nil
+		}),
 		fakeLimits{},
 	).RoundTrip(req)
 	require.NoError(t, err)
@@ -447,7 +503,19 @@ func promqlResult(v parser.Value) (*int, http.Handler) {
 		}
 		count++
 	})
+}
 
+func seriesResult(v logproto.SeriesResponse) (*int, http.Handler) {
+	count := 0
+	var lock sync.Mutex
+	return &count, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		lock.Lock()
+		defer lock.Unlock()
+		if err := marshal.WriteSeriesResponseJSON(v, w); err != nil {
+			panic(err)
+		}
+		count++
+	})
 }
 
 type fakeRoundTripper struct {

pkg/querier/queryrange/split_by_interval.go

@@ -153,7 +153,7 @@ func (h *splitByInterval) loop(ctx context.Context, ch <-chan *lokiResult) {
 }
 
 func (h *splitByInterval) Do(ctx context.Context, r queryrange.Request) (queryrange.Response, error) {
-	lokiRequest := r.(*LokiRequest)
+	//lokiRequest := r.(*LokiRequest)
 
 	userid, err := user.ExtractOrgID(ctx)
 	if err != nil {
@@ -166,7 +166,7 @@ func (h *splitByInterval) Do(ctx context.Context, r queryrange.Request) (queryra
 		return h.next.Do(ctx, r)
 	}
 
-	intervals := splitByTime(lokiRequest, interval)
+	intervals := splitByTime(r, interval)
 	h.metrics.splits.Observe(float64(len(intervals)))
 
 	// no interval should not be processed by the frontend.
@@ -179,10 +179,20 @@ func (h *splitByInterval) Do(ctx context.Context, r queryrange.Request) (queryra
 
 	}
 
-	if lokiRequest.Direction == logproto.BACKWARD {
+	var limit int64
-		for i, j := 0, len(intervals)-1; i < j; i, j = i+1, j-1 {
+	switch req := r.(type) {
-			intervals[i], intervals[j] = intervals[j], intervals[i]
+	case *LokiRequest:
+		limit = int64(req.Limit)
+		if req.Direction == logproto.BACKWARD {
+			for i, j := 0, len(intervals)-1; i < j; i, j = i+1, j-1 {
+				intervals[i], intervals[j] = intervals[j], intervals[i]
+			}
 		}
+	case *LokiSeriesRequest:
+		// Set this to 0 since this is not used in Series Request.
+		limit = 0
+	default:
+		return nil, httpgrpc.Errorf(http.StatusBadRequest, "unknown request type")
 	}
 
 	input := make([]*lokiResult, 0, len(intervals))
@@ -193,29 +203,49 @@ func (h *splitByInterval) Do(ctx context.Context, r queryrange.Request) (queryra
 		})
 	}
 
-	resps, err := h.Process(ctx, h.limits.MaxQueryParallelism(userid), int64(lokiRequest.Limit), input)
+	resps, err := h.Process(ctx, h.limits.MaxQueryParallelism(userid), limit, input)
 	if err != nil {
 		return nil, err
 	}
 	return h.merger.MergeResponse(resps...)
 }
 
-func splitByTime(r *LokiRequest, interval time.Duration) []queryrange.Request {
+func splitByTime(req queryrange.Request, interval time.Duration) []queryrange.Request {
 	var reqs []queryrange.Request
-	for start := r.StartTs; start.Before(r.EndTs); start = start.Add(interval) {
+
-		end := start.Add(interval)
+	switch r := req.(type) {
-		if end.After(r.EndTs) {
+	case *LokiRequest:
-			end = r.EndTs
+		for start := r.StartTs; start.Before(r.EndTs); start = start.Add(interval) {
+			end := start.Add(interval)
+			if end.After(r.EndTs) {
+				end = r.EndTs
+			}
+			reqs = append(reqs, &LokiRequest{
+				Query:     r.Query,
+				Limit:     r.Limit,
+				Step:      r.Step,
+				Direction: r.Direction,
+				Path:      r.Path,
+				StartTs:   start,
+				EndTs:     end,
+			})
 		}
-		reqs = append(reqs, &LokiRequest{
+		return reqs
-			Query:     r.Query,
+	case *LokiSeriesRequest:
-			Limit:     r.Limit,
+		for start := r.StartTs; start.Before(r.EndTs); start = start.Add(interval) {
-			Step:      r.Step,
+			end := start.Add(interval)
-			Direction: r.Direction,
+			if end.After(r.EndTs) {
-			Path:      r.Path,
+				end = r.EndTs
-			StartTs:   start,
+			}
-			EndTs:     end,
+			reqs = append(reqs, &LokiSeriesRequest{
-		})
+				Match:   r.Match,
+				Path:    r.Path,
+				StartTs: start,
+				EndTs:   end,
+			})
+		}
+		return reqs
+	default:
+		return nil
 	}
-	return reqs
 }

pkg/querier/queryrange/split_by_interval_test.go

@@ -22,7 +22,7 @@ func Test_splitQuery(t *testing.T) {
 
 	tests := []struct {
 		name     string
-		req      *LokiRequest
+		req      queryrange.Request
 		interval time.Duration
 		want     []queryrange.Request
 	}{
@@ -72,6 +72,28 @@ func Test_splitQuery(t *testing.T) {
 				},
 			},
 		},
+		{
+			"3 intervals series",
+			&LokiSeriesRequest{
+				StartTs: time.Date(2019, 12, 9, 12, 0, 0, 1, time.UTC),
+				EndTs:   time.Date(2019, 12, 9, 16, 0, 0, 2, time.UTC),
+			},
+			2 * time.Hour,
+			[]queryrange.Request{
+				&LokiSeriesRequest{
+					StartTs: time.Date(2019, 12, 9, 12, 0, 0, 1, time.UTC),
+					EndTs:   time.Date(2019, 12, 9, 14, 0, 0, 1, time.UTC),
+				},
+				&LokiSeriesRequest{
+					StartTs: time.Date(2019, 12, 9, 14, 0, 0, 1, time.UTC),
+					EndTs:   time.Date(2019, 12, 9, 16, 0, 0, 1, time.UTC),
+				},
+				&LokiSeriesRequest{
+					StartTs: time.Date(2019, 12, 9, 16, 0, 0, 1, time.UTC),
+					EndTs:   time.Date(2019, 12, 9, 16, 0, 0, 2, time.UTC),
+				},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -251,6 +273,71 @@ func Test_splitByInterval_Do(t *testing.T) {
 
 }
 
+func Test_series_splitByInterval_Do(t *testing.T) {
+	ctx := user.InjectOrgID(context.Background(), "1")
+	next := queryrange.HandlerFunc(func(_ context.Context, r queryrange.Request) (queryrange.Response, error) {
+		return &LokiSeriesResponse{
+			Status:  "success",
+			Version: uint32(loghttp.VersionV1),
+			Data: []logproto.SeriesIdentifier{
+				{
+					Labels: map[string]string{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+				},
+				{
+					Labels: map[string]string{"filename": "/var/hostlog/test.log", "job": "varlogs"},
+				},
+				{
+					Labels: map[string]string{"filename": "/var/hostlog/test.log", "job": "varlogs"},
+				},
+			},
+		}, nil
+	})
+
+	l := WithDefaultLimits(fakeLimits{}, queryrange.Config{SplitQueriesByInterval: time.Hour})
+	split := SplitByIntervalMiddleware(
+		l,
+		lokiCodec,
+		nilMetrics,
+	).Wrap(next)
+
+	tests := []struct {
+		name string
+		req  *LokiSeriesRequest
+		want *LokiSeriesResponse
+	}{
+		{
+			"backward",
+			&LokiSeriesRequest{
+				StartTs: time.Unix(0, 0),
+				EndTs:   time.Unix(0, (4 * time.Hour).Nanoseconds()),
+				Match:   []string{`{job="varlogs"}`},
+				Path:    "/loki/api/v1/series",
+			},
+			&LokiSeriesResponse{
+				Status:  "success",
+				Version: 1,
+				Data: []logproto.SeriesIdentifier{
+					{
+						Labels: map[string]string{"filename": "/var/hostlog/apport.log", "job": "varlogs"},
+					},
+					{
+						Labels: map[string]string{"filename": "/var/hostlog/test.log", "job": "varlogs"},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			res, err := split.Do(ctx, tt.req)
+			require.NoError(t, err)
+			require.Equal(t, tt.want, res)
+		})
+	}
+
+}
+
 func Test_ExitEarly(t *testing.T) {
 	ctx := user.InjectOrgID(context.Background(), "1")