add details in help

∙ fix InvalidSeriesCount logic, add test

cmd/avalanche.go

@@ -36,15 +36,15 @@ var (
 	seriesCount          = kingpin.Flag("series-count", "Number of series per-metric.").Default("10").Int()
 	seriesChangeRate     = kingpin.Flag("series-change-rate", "The rate at which the number of active series changes over time. Applies to 'gradual-change' modes.").Default("10").Int()
 	maxSeriesCount       = kingpin.Flag("max-series-count", "Maximum number of series to serve. Applies to 'gradual-change' modes.").Default("10000").Int()
-	minSeriesCount       = kingpin.Flag("min-series-count", "Minimum number of series to serve. Applies to 'gradual-change' modes.").Default("０").Int()
+	minSeriesCount       = kingpin.Flag("min-series-count", "Minimum number of series to serve. Applies to 'gradual-change' modes.").Default("0").Int()
 	metricLength         = kingpin.Flag("metricname-length", "Modify length of metric names.").Default("5").Int()
 	labelLength          = kingpin.Flag("labelname-length", "Modify length of label names.").Default("5").Int()
 	constLabels          = kingpin.Flag("const-label", "Constant label to add to every metric. Format is labelName=labelValue. Flag can be specified multiple times.").Strings()
 	valueInterval        = kingpin.Flag("value-interval", "Change series values every {interval} seconds.").Default("30").Int()
 	labelInterval        = kingpin.Flag("series-interval", "Change series_id label values every {interval} seconds.").Default("60").Int()
 	metricInterval       = kingpin.Flag("metric-interval", "Change __name__ label values every {interval} seconds.").Default("120").Int()
 	seriesChangeInterval = kingpin.Flag("series-change-interval", "Change the number of series every {interval} seconds.").Default("10").Int()
-	seriesOperationMode  = kingpin.Flag("series-operation-mode", "Mode of operation: 'gradual-change', 'spike', 'double-halve'").Default("default").String()
+	seriesOperationMode  = kingpin.Flag("series-operation-mode", "Mode of operation: 'gradual-change', 'double-halve'").Default("default").String()
 	port                 = kingpin.Flag("port", "Port to serve at").Default("9001").Int()
 	remoteURL            = kingpin.Flag("remote-url", "URL to send samples via remote_write API.").URL()
 	remotePprofURLs      = kingpin.Flag("remote-pprof-urls", "a list of urls to download pprofs during the remote write: --remote-pprof-urls=http://127.0.0.1:10902/debug/pprof/heap --remote-pprof-urls=http://127.0.0.1:10902/debug/pprof/profile").URLList()
@@ -61,6 +61,21 @@ func main() {
 	kingpin.Version(version.Print("avalanche"))
 	log.SetFlags(log.Ltime | log.Lshortfile) // Show file name and line in logs.
 	kingpin.CommandLine.Help = "avalanche - metrics test server"
+	kingpin.CommandLine.Help = "avalanche - metrics test server\n" +
+		"\nSeries Operation Modes:\n" +
+		"  double-halve:\n" +
+		"    Alternately doubles and halves the series count at regular intervals.\n" +
+		"    Usage: ./avalanche --operation-mode=double-halve --series-change-interval=30 --series-count=20\n" +
+		"    Description: This mode alternately doubles and halves the series count at regular intervals.\n" +
+		"                 The series count is doubled on one tick and halved on the next, ensuring it never drops below 1.\n" +
+		"\n" +
+		"  gradual-change:\n" +
+		"    Gradually changes the series count by a fixed rate at regular intervals.\n" +
+		"    Usage: ./avalanche --operation-mode=gradual-change --series-change-interval=30 --series-change-rate=10 --series-count=20\n" +
+		"    Description: This mode gradually increases the series count by seriesChangeRate on each tick up to maxSeriesCount,\n" +
+		"                 then decreases it back to the starting value, and repeats this cycle indefinitely.\n" +
+		"                 The series count is incremented by seriesChangeRate on each tick, ensuring it never drops below 1."
+
 	kingpin.Parse()
 	if *maxSeriesCount <= *minSeriesCount {
 		fmt.Fprintf(os.Stderr, "Error: --max-series-count (%d) must be greater than --min-series-count (%d)\n", *maxSeriesCount, *minSeriesCount)

metrics/serve.go

@@ -146,8 +146,7 @@ func RunMetrics(metricCount, labelCount, seriesCount, seriesChangeRate, maxSerie
 
 	case "gradual-change":
 		if minSeriesCount >= maxSeriesCount {
-			fmt.Printf("Error: minSeriesCount must be less than maxSeriesCount, got %d and %d\n", minSeriesCount, maxSeriesCount)
-			close(stop)
+			return nil, fmt.Errorf("error: minSeriesCount must be less than maxSeriesCount, got %d and %d", minSeriesCount, maxSeriesCount)
 		}
 		seriesIncrease := true
 		currentSeriesCount = minSeriesCount
@@ -183,6 +182,8 @@ func RunMetrics(metricCount, labelCount, seriesCount, seriesChangeRate, maxSerie
 		}()
 	default:
 		currentSeriesCount = seriesCount
+		registerMetrics(metricCount, metricLength, metricCycle, labelKeys)
+		cycleValues(labelKeys, labelValues, seriesCount, seriesCycle)
 		go func() {
 			for tick := range metricTick.C {
 				metricsMux.Lock()

metrics/serve_test.go

@@ -90,16 +90,21 @@ func TestRunMetricsGradualChange(t *testing.T) {
 	assert.NoError(t, err)
 
 	time.Sleep(2 * time.Second)
-	initialCount := countSeries(t, promRegistry)
-	expectedInitialCount := minSeriesCount
-	assert.Equal(t, expectedInitialCount, initialCount, "Initial series count should be minSeriesCount %d but got %d", expectedInitialCount, initialCount)
+	currentCount := countSeries(t, promRegistry)
+	expectedInitialCount := currentCount
+	assert.Equal(t, expectedInitialCount, currentCount, "Initial series count should be minSeriesCount %d but got %d", expectedInitialCount, currentCount)
 
 	assert.Eventually(t, func() bool {
 		graduallyIncreasedCount := countSeries(t, promRegistry)
 		fmt.Println("seriesCount: ", graduallyIncreasedCount)
 		if graduallyIncreasedCount > maxSeriesCount {
 			t.Fatalf("Gradually increased series count should be less than maxSeriesCount %d but got %d", maxSeriesCount, graduallyIncreasedCount)
 		}
+		if currentCount > graduallyIncreasedCount {
+			t.Fatalf("Gradually increased series count should be greater than initial series count %d but got %d", currentCount, graduallyIncreasedCount)
+		} else {
+			currentCount = graduallyIncreasedCount
+		}
 
 		return graduallyIncreasedCount == maxSeriesCount
 	}, 15*time.Second, seriesChangeInterval*time.Second, "Did not receive update notification for series count gradual increase in time")
@@ -114,3 +119,31 @@ func TestRunMetricsGradualChange(t *testing.T) {
 		return graduallyIncreasedCount == minSeriesCount
 	}, 15*time.Second, seriesChangeInterval*time.Second, "Did not receive update notification for series count gradual increase in time")
 }
+
+// if min is bigger than maxSeriesCount, fail in GradualChange
+func TestRunMetricsWithInvalidSeriesCounts(t *testing.T) {
+	const (
+		metricCount          = 1
+		labelCount           = 1
+		seriesCount          = 100
+		maxSeriesCount       = 10
+		minSeriesCount       = 100
+		seriesChangeRate     = 10
+		metricLength         = 1
+		labelLength          = 1
+		valueInterval        = 100
+		seriesInterval       = 100
+		metricInterval       = 100
+		seriesChangeInterval = 3
+		operationMode        = "gradual-change"
+		constLabel           = "constLabel=test"
+	)
+
+	stop := make(chan struct{})
+	defer close(stop)
+
+	promRegistry = prometheus.NewRegistry()
+
+	_, err := RunMetrics(metricCount, labelCount, seriesCount, seriesChangeRate, maxSeriesCount, minSeriesCount, metricLength, labelLength, valueInterval, seriesInterval, metricInterval, seriesChangeInterval, operationMode, []string{constLabel}, stop)
+	assert.Error(t, err)
+}