storage/remote: add test showing bug prometheus#12605

Add test for bug prometheus#12605 for starters.

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@vinted.com>

storage/remote/read_handler_test.go

@@ -18,8 +18,10 @@ import (
 	"context"
 	"errors"
 	"io"
+	"math"
 	"net/http"
 	"net/http/httptest"
+	"sort"
 	"testing"
 	"time"
 
@@ -195,6 +197,103 @@ func BenchmarkStreamReadEndpoint(b *testing.B) {
 	}
 }
 
+type chunkedResponses []*prompb.ChunkedReadResponse
+
+var _ = (sort.Interface)(&chunkedResponses{})
+
+func (r chunkedResponses) Len() int {
+	return len(r)
+}
+
+func (r chunkedResponses) Less(i, j int) bool {
+	lblsi := map[string]string{}
+	for _, li := range r[i].ChunkedSeries[0].Labels {
+		lblsi[li.Name] = li.Value
+	}
+
+	lblsj := map[string]string{}
+	for _, lj := range r[j].ChunkedSeries[0].Labels {
+		lblsj[lj.Name] = lj.Value
+	}
+
+	return labels.Compare(labels.FromMap(lblsi), labels.FromMap(lblsj)) < 0
+}
+
+func (r chunkedResponses) Swap(i, j int) {
+	r[i], r[j] = r[j], r[i]
+}
+
+// Test for https://github.com/prometheus/prometheus/issues/12605.
+func TestRemoteReadSortedResult(t *testing.T) {
+	store := promql.LoadedStorage(t, `
+		load 1m
+			test_metric1{a="1", b="2", c="3"} 0+100x119
+			test_metric1{a="1", b="2", c="3", d="4"} 0+100x120
+			test_metric1{a="1", c="5"} 0+100x120
+			test_metric1{a="1", c="6"} 0+100x120
+	`)
+	defer store.Close()
+
+	api := NewReadHandler(nil, nil, store, func() config.Config {
+		return config.Config{
+			GlobalConfig: config.GlobalConfig{
+				ExternalLabels: labels.FromStrings("b", "1"),
+			},
+		}
+	},
+		1e6, 1, math.MaxInt,
+	)
+
+	// Encode the request.
+	matcher, err := labels.NewMatcher(labels.MatchEqual, "a", "1")
+	require.NoError(t, err)
+
+	query, err := ToQuery(0, 14400001, []*labels.Matcher{matcher}, &storage.SelectHints{
+		Step:  1,
+		Func:  "avg",
+		Start: 0,
+		End:   14400001,
+	})
+	require.NoError(t, err)
+
+	req := &prompb.ReadRequest{
+		Queries:               []*prompb.Query{query},
+		AcceptedResponseTypes: []prompb.ReadRequest_ResponseType{prompb.ReadRequest_STREAMED_XOR_CHUNKS},
+	}
+	data, err := proto.Marshal(req)
+	require.NoError(t, err)
+
+	compressed := snappy.Encode(nil, data)
+	request, err := http.NewRequest("POST", "", bytes.NewBuffer(compressed))
+	require.NoError(t, err)
+
+	recorder := httptest.NewRecorder()
+	api.ServeHTTP(recorder, request)
+
+	require.Equal(t, 2, recorder.Code/100)
+
+	require.Equal(t, "application/x-streamed-protobuf; proto=prometheus.ChunkedReadResponse", recorder.Result().Header.Get("Content-Type"))
+	require.Equal(t, "", recorder.Result().Header.Get("Content-Encoding"))
+
+	var results chunkedResponses
+	stream := NewChunkedReader(recorder.Result().Body, DefaultChunkedReadLimit, nil)
+	for {
+		res := &prompb.ChunkedReadResponse{}
+		err := stream.NextProto(res)
+		if errors.Is(err, io.EOF) {
+			break
+		}
+		require.NoError(t, err)
+		results = append(results, res)
+	}
+
+	require.Equal(t, 4, len(results))
+
+	// NOTE(GiedriusS): with https://github.com/prometheus/prometheus/issues/12605 fixed
+	// this should return true.
+	require.Equal(t, false, sort.IsSorted(results))
+}
+
 func TestStreamReadEndpoint(t *testing.T) {
 	// First with 120 float samples. We expect 1 frame with 1 chunk.
 	// Second with 121 float samples, We expect 1 frame with 2 chunks.