Add test to show data race in batchTimeSeries()

Signed-off-by: Arthur Silva Sens <[email protected]>

exporter/prometheusremotewriteexporter/exporter_concurrency_test.go

@@ -0,0 +1,138 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package prometheusremotewriteexporter
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/gogo/protobuf/proto"
+	"github.com/golang/snappy"
+	"github.com/prometheus/prometheus/prompb"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/collector/component/componenttest"
+	"go.opentelemetry.io/collector/config/confighttp"
+	"go.opentelemetry.io/collector/config/configretry"
+	"go.opentelemetry.io/collector/config/configtelemetry"
+	"go.opentelemetry.io/collector/exporter/exportertest"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal/testdata"
+)
+
+// Test everything works when there is more than one goroutine calling PushMetrics.
+// Today we only use 1 worker per exporter, but the intention of this test is to future-proof in case it changes.
+func Test_PushMetricsConcurrent(t *testing.T) {
+	n := 1000
+	ms := make([]pmetric.Metrics, n)
+	testIDKey := "test_id"
+	for i := 0; i < n; i++ {
+		m := testdata.GenerateMetricsOneMetric()
+		dps := m.ResourceMetrics().At(0).ScopeMetrics().At(0).Metrics().At(0).Sum().DataPoints()
+		for j := 0; j < dps.Len(); j++ {
+			dp := dps.At(j)
+			dp.Attributes().PutInt(testIDKey, int64(i))
+		}
+		ms[i] = m
+	}
+	received := make(map[int]prompb.TimeSeries)
+	var mu sync.Mutex
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			t.Fatal(err)
+		}
+		assert.NotNil(t, body)
+		// Receives the http requests and unzip, unmarshalls, and extracts TimeSeries
+		assert.Equal(t, "0.1.0", r.Header.Get("X-Prometheus-Remote-Write-Version"))
+		assert.Equal(t, "snappy", r.Header.Get("Content-Encoding"))
+		var unzipped []byte
+
+		dest, err := snappy.Decode(unzipped, body)
+		assert.NoError(t, err)
+
+		wr := &prompb.WriteRequest{}
+		ok := proto.Unmarshal(dest, wr)
+		assert.NoError(t, ok)
+		assert.Len(t, wr.Timeseries, 2)
+		ts := wr.Timeseries[0]
+		foundLabel := false
+		for _, label := range ts.Labels {
+			if label.Name == testIDKey {
+				id, err := strconv.Atoi(label.Value)
+				assert.NoError(t, err)
+				mu.Lock()
+				_, ok := received[id]
+				assert.False(t, ok) // fail if we already saw it
+				received[id] = ts
+				mu.Unlock()
+				foundLabel = true
+				break
+			}
+		}
+		assert.True(t, foundLabel)
+		w.WriteHeader(http.StatusOK)
+	}))
+
+	defer server.Close()
+
+	// Adjusted retry settings for faster testing
+	retrySettings := configretry.BackOffConfig{
+		Enabled:         true,
+		InitialInterval: 100 * time.Millisecond, // Shorter initial interval
+		MaxInterval:     1 * time.Second,        // Shorter max interval
+		MaxElapsedTime:  2 * time.Second,        // Shorter max elapsed time
+	}
+	clientConfig := confighttp.NewDefaultClientConfig()
+	clientConfig.Endpoint = server.URL
+	clientConfig.ReadBufferSize = 0
+	clientConfig.WriteBufferSize = 512 * 1024
+	cfg := &Config{
+		Namespace:         "",
+		ClientConfig:      clientConfig,
+		MaxBatchSizeBytes: 3000000,
+		RemoteWriteQueue:  RemoteWriteQueue{NumConsumers: 1},
+		TargetInfo: &TargetInfo{
+			Enabled: true,
+		},
+		CreatedMetric: &CreatedMetric{
+			Enabled: false,
+		},
+		BackOffConfig: retrySettings,
+	}
+
+	assert.NotNil(t, cfg)
+	set := exportertest.NewNopSettings()
+	set.MetricsLevel = configtelemetry.LevelBasic
+
+	prwe, nErr := newPRWExporter(cfg, set)
+
+	require.NoError(t, nErr)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	require.NoError(t, prwe.Start(ctx, componenttest.NewNopHost()))
+	defer func() {
+		require.NoError(t, prwe.Shutdown(ctx))
+	}()
+
+	var wg sync.WaitGroup
+	wg.Add(n)
+	for _, m := range ms {
+		go func() {
+			err := prwe.PushMetrics(ctx, m)
+			assert.NoError(t, err)
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+	assert.Len(t, received, n)
+}