Add concurrent write test

This adds an end-to-end concurrent write test. The data
generation here is modeled after how prometheus would send
data. Namely requests come from queues that have non-overlapping
series but do have overlapping metrics.

pkg/pgmodel/end_to_end_tests/write_test.go

@@ -0,0 +1,241 @@
+package end_to_end_tests
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"math/rand"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/gogo/protobuf/proto"
+	"github.com/golang/snappy"
+	"github.com/jackc/pgx/v4/pgxpool"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/model"
+	"github.com/prometheus/common/route"
+	"github.com/timescale/timescale-prometheus/pkg/api"
+	"github.com/timescale/timescale-prometheus/pkg/internal/testhelpers"
+	"github.com/timescale/timescale-prometheus/pkg/pgmodel"
+	"github.com/timescale/timescale-prometheus/pkg/prompb"
+	"github.com/timescale/timescale-prometheus/pkg/util"
+)
+
+type dataGenerator struct {
+	metricGroup int //nonoverlapping metrics
+	queueID     int
+
+	metricsPerGroup    int
+	labelSetsPerMetric int
+	maxSamples         int64
+	deltaTime          int64
+	deltaValue         float64
+	currentTime        int64
+}
+
+func (t *dataGenerator) generateTimeseries() []prompb.TimeSeries {
+	metrics := []prompb.TimeSeries{}
+	for metric := 0; metric < t.metricsPerGroup; metric++ {
+		for instance := 0; instance < t.labelSetsPerMetric; instance++ {
+			labelSet := []prompb.Label{
+				{Name: pgmodel.MetricNameLabelName, Value: fmt.Sprintf("metric_%d_%d", t.metricGroup, metric)},
+				{Name: "foo", Value: fmt.Sprintf("bar_%d", t.queueID)}, //queues have non-overlapping label sets
+				{Name: "instance", Value: fmt.Sprintf("%d", instance)},
+			}
+
+			if instance%2 == 0 {
+				labelSet = append(labelSet,
+					prompb.Label{Name: "sometimes_label", Value: "constant"})
+			}
+
+			metrics = append(metrics, prompb.TimeSeries{
+				Labels: labelSet,
+			})
+		}
+
+	}
+
+	numSamples := rand.Int63n(t.maxSamples)
+	for i := range metrics {
+		metrics[i].Samples = t.generateSamples(numSamples)
+	}
+	t.currentTime += t.maxSamples*t.deltaTime + int64(1)
+	return metrics
+}
+
+func (t *dataGenerator) generateSamples(count int64) []prompb.Sample {
+	samples := make([]prompb.Sample, 0, 3)
+	i := int64(0)
+	for i < count {
+		samples = append(samples, prompb.Sample{
+			Timestamp: t.currentTime + (t.deltaTime * int64(i)),
+			Value:     float64(t.metricGroup*10000) + (t.deltaValue * float64(i)),
+		})
+		i++
+	}
+
+	return samples
+}
+
+func getHTTPWriteRequest(protoRequest *prompb.WriteRequest) (*http.Request, error) {
+	data, err := proto.Marshal(protoRequest)
+	if err != nil {
+		return nil, err
+	}
+
+	body := string(snappy.Encode(nil, data))
+	u, err := url.Parse(fmt.Sprintf("http://%s:%d/write", testhelpers.PromHost, testhelpers.PromPort.Int()))
+
+	if err != nil {
+		return nil, err
+	}
+	return http.NewRequest(
+		"POST",
+		u.String(),
+		strings.NewReader(body),
+	)
+}
+
+func sendWriteRequest(t testing.TB, router *route.Router, ts []prompb.TimeSeries) {
+	req, err := getHTTPWriteRequest(&prompb.WriteRequest{Timeseries: ts})
+	if err != nil {
+		t.Fatalf("unable to create PromQL label names request: %v", err)
+	}
+
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+
+	tsResp := rec.Result()
+	if rec.Code != 200 {
+		t.Fatal(rec.Code)
+	}
+
+	_, err = ioutil.ReadAll(tsResp.Body)
+	if err != nil {
+		t.Fatalf("unexpected error returned when reading connector response body:\n%s\n", err.Error())
+	}
+	defer tsResp.Body.Close()
+}
+
+func verifyTimeseries(t testing.TB, db *pgxpool.Pool, tsSlice []prompb.TimeSeries) {
+	for tsIdx := range tsSlice {
+		ts := tsSlice[tsIdx]
+		name := ""
+		names := []string{}
+		values := []string{}
+		for labelIdx := range ts.Labels {
+			label := ts.Labels[labelIdx]
+			if label.Name == pgmodel.MetricNameLabelName {
+				name = label.Value
+
+			}
+			names = append(names, label.Name)
+			values = append(values, label.Value)
+		}
+		if name == "" {
+			t.Fatal("No ts series metric name found")
+		}
+		for sampleIdx := range ts.Samples {
+			sample := ts.Samples[sampleIdx]
+			rows, err := db.Query(context.Background(), fmt.Sprintf("SELECT value FROM prom_data.%s WHERE time = $1 and series_id = (SELECT series_id FROM _prom_catalog.get_or_create_series_id_for_kv_array($2, $3, $4))",
+				name), model.Time(sample.Timestamp).Time(), name, names, values)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer rows.Close()
+			count := 0
+			for rows.Next() {
+				var val *float64
+				err := rows.Scan(&val)
+				if err != nil {
+					t.Fatal(err)
+				}
+				if val == nil {
+					t.Fatal("NULL value")
+				}
+				if *val != sample.Value {
+					t.Errorf("Unexpected value: got %v, unexpected %v", *val, sample.Value)
+				}
+				count++
+			}
+			if count != 1 {
+				t.Errorf("Unexpected count: %d", count)
+			}
+		}
+	}
+}
+
+func getWriteRouter(t testing.TB, db *pgxpool.Pool) *route.Router {
+	r, err := pgmodel.NewPgxIngestor(db)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	writeHandler := api.Write(r, nil, &api.Metrics{
+		LeaderGauge:       prometheus.NewGauge(prometheus.GaugeOpts{}),
+		ReceivedSamples:   prometheus.NewCounter(prometheus.CounterOpts{}),
+		FailedSamples:     prometheus.NewCounter(prometheus.CounterOpts{}),
+		SentSamples:       prometheus.NewCounter(prometheus.CounterOpts{}),
+		SentBatchDuration: prometheus.NewHistogram(prometheus.HistogramOpts{}),
+		WriteThroughput:   util.NewThroughputCalc(time.Second),
+	})
+
+	router := route.New()
+	router.Post("/write", writeHandler.ServeHTTP)
+	return router
+}
+
+func sendConcurrentWrites(t testing.TB, db *pgxpool.Pool, queues int, metricGroups int, totalRequests int, duplicates bool) {
+	router := getWriteRouter(t, db)
+
+	wg := sync.WaitGroup{}
+	for i := 0; i < queues; i++ {
+		for m := 0; m < metricGroups; m++ {
+			queueIdx := i
+			midx := m
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				dg := dataGenerator{
+					metricGroup: midx,
+					queueID:     queueIdx,
+
+					metricsPerGroup:    2,
+					labelSetsPerMetric: 2,
+					maxSamples:         5,
+					deltaTime:          2000,
+					deltaValue:         3,
+					currentTime:        startTime,
+				}
+				tss := [][]prompb.TimeSeries{}
+				for requestNo := 0; requestNo < totalRequests; requestNo++ {
+					ts := dg.generateTimeseries()
+					sendWriteRequest(t, router, ts)
+					if duplicates {
+						sendWriteRequest(t, router, ts)
+					}
+					tss = append(tss, ts)
+				}
+				for i := range tss {
+					verifyTimeseries(t, db, tss[i])
+				}
+			}()
+		}
+	}
+	wg.Wait()
+}
+
+func TestWrite(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test")
+	}
+	withDB(t, *testDatabase, func(db *pgxpool.Pool, t testing.TB) {
+		sendConcurrentWrites(t, db, 2, 2, 5, false)
+		sendConcurrentWrites(t, db, 2, 2, 3, true)
+	})
+}