add tests; remove periodic.go

examples/metrics/metrics.go

@@ -45,19 +45,29 @@ func main() {
 	ctx := context.Background()
 	meter := metricglobal.Meter("testing")
 
-	// This example shows 1 instrument each for (UpDown)?(SumObserver|Counter)
-	// The two monotonic instruments of these have a fixed rate of +1.
-	// The two non-monotonic instruments of these have a fixed rate of -1.
-	// There are 2 example ValueObserver instruments (one a Gaussian, one a Sine wave).
-	//
-	// TODO: ValueRecorder examples.
+	// This example shows 1 instrument each for synchronous and
+	// asynchronous Counter and UpDownCounter.  The two monotonic
+	// instruments of these have a fixed rate of +1.  The two
+	// non-monotonic instruments of these have a fixed rate of -1.
+	// There are 2 example Gauge instruments (one a Gaussian, one
+	// a Sine wave), and one Histogram.
 
 	c1, _ := meter.SyncInt64().Counter(prefix + "counter")
 	c2, _ := meter.SyncInt64().UpDownCounter(prefix + "updowncounter")
+	hist, _ := meter.SyncFloat64().Histogram(prefix + "histogram")
 	go func() {
 		for {
 			c1.Add(ctx, 1)
 			c2.Add(ctx, -1)
+
+			secs := float64(time.Now().UnixNano()) / float64(time.Second)
+			mult := math.Sin(secs / (40 * math.Pi))
+			mult *= mult
+
+			for i := 0; i < 10000; i++ {
+				hist.Record(ctx, mult*(100+rand.NormFloat64()*100))
+			}
+
 			time.Sleep(time.Second)
 		}
 	}()
@@ -114,6 +124,7 @@ func main() {
 		func(ctx context.Context) {
 			secs := float64(time.Now().UnixNano()) / float64(time.Second)
 
+			sineWave.Observe(ctx, math.Sin(secs/(50*math.Pi)), attribute.String("period", "fastest"))
 			sineWave.Observe(ctx, math.Sin(secs/(200*math.Pi)), attribute.String("period", "fast"))
 			sineWave.Observe(ctx, math.Sin(secs/(1000*math.Pi)), attribute.String("period", "regular"))
 			sineWave.Observe(ctx, math.Sin(secs/(5000*math.Pi)), attribute.String("period", "slow"))

launcher/config.go

@@ -141,6 +141,15 @@ func WithMetricReportingPeriod(p time.Duration) Option {
 	}
 }
 
+// WithMetricTemporalityPreference controls the temporality preference
+// used for Counter and Histogram (only not for UpDownCounter, which
+// ignores this preference for specified reasons).
+func WithMetricTemporalityPreference(prefName string) Option {
+	return func(c *Config) {
+		c.MetricTemporalityPreference = prefName
+	}
+}
+
 // WithMetricEnabled configures whether metrics should be enabled
 func WithMetricsEnabled(enabled bool) Option {
 	return func(c *Config) {
@@ -199,6 +208,7 @@ type Config struct {
 	LogLevel                       string            `env:"OTEL_LOG_LEVEL,default=info"`
 	Propagators                    []string          `env:"OTEL_PROPAGATORS,default=b3"`
 	MetricReportingPeriod          string            `env:"OTEL_EXPORTER_OTLP_METRIC_PERIOD,default=30s"`
+	MetricTemporalityPreference    string            `env:"OTEL_EXPORTER_OTLP_METRIC_TEMPORALITY_PREFERENCE,default=cumulative"`
 	ResourceAttributes             map[string]string
 	Resource                       *resource.Resource
 	logger                         Logger
@@ -361,11 +371,12 @@ func setupMetrics(c Config) (func() error, error) {
 		return nil, nil
 	}
 	return pipelines.NewMetricsPipeline(pipelines.PipelineConfig{
-		Endpoint:        c.MetricExporterEndpoint,
-		Insecure:        c.MetricExporterEndpointInsecure,
-		Headers:         c.Headers,
-		Resource:        c.Resource,
-		ReportingPeriod: c.MetricReportingPeriod,
+		Endpoint:              c.MetricExporterEndpoint,
+		Insecure:              c.MetricExporterEndpointInsecure,
+		Headers:               c.Headers,
+		Resource:              c.Resource,
+		ReportingPeriod:       c.MetricReportingPeriod,
+		TemporalityPreference: c.MetricTemporalityPreference,
 	})
 }
 

launcher/config_test.go

@@ -314,6 +314,7 @@ func TestDefaultConfig(t *testing.T) {
 		MetricExporterEndpointInsecure: false,
 		MetricReportingPeriod:          "30s",
 		MetricsEnabled:                 true,
+		MetricTemporalityPreference:    "cumulative",
 		LogLevel:                       "info",
 		Propagators:                    []string{"b3"},
 		Resource:                       resource.NewWithAttributes(semconv.SchemaURL, attributes...),
@@ -349,6 +350,7 @@ func TestEnvironmentVariables(t *testing.T) {
 		MetricExporterEndpoint:         "metrics-url",
 		MetricExporterEndpointInsecure: true,
 		MetricReportingPeriod:          "30s",
+		MetricTemporalityPreference:    "delta",
 		LogLevel:                       "debug",
 		Propagators:                    []string{"b3", "w3c"},
 		Resource:                       resource.NewWithAttributes(semconv.SchemaURL, attributes...),
@@ -372,6 +374,7 @@ func TestConfigurationOverrides(t *testing.T) {
 		WithSpanExporterInsecure(false),
 		WithMetricExporterEndpoint("override-metrics-url"),
 		WithMetricExporterInsecure(false),
+		WithMetricTemporalityPreference("stateless"),
 		WithLogLevel("info"),
 		WithLogger(logger),
 		WithErrorHandler(handler),
@@ -395,6 +398,7 @@ func TestConfigurationOverrides(t *testing.T) {
 		MetricExporterEndpoint:         "override-metrics-url",
 		MetricExporterEndpointInsecure: false,
 		MetricReportingPeriod:          "30s",
+		MetricTemporalityPreference:    "stateless",
 		Headers:                        map[string]string{"lightstep-access-token": "override-access-token"},
 		LogLevel:                       "info",
 		Propagators:                    []string{"b3"},
@@ -600,6 +604,7 @@ func setEnvironment() {
 	os.Setenv("OTEL_LOG_LEVEL", "debug")
 	os.Setenv("OTEL_PROPAGATORS", "b3,w3c")
 	os.Setenv("OTEL_RESOURCE_ATTRIBUTES", "service.name=test-service-name-b")
+	os.Setenv("OTEL_EXPORTER_OTLP_METRIC_TEMPORALITY_PREFERENCE", "delta")
 	os.Setenv("LS_METRICS_ENABLED", "false")
 }
 
@@ -616,6 +621,7 @@ func unsetEnvironment() {
 		"OTEL_PROPAGATORS",
 		"OTEL_RESOURCE_ATTRIBUTES",
 		"OTEL_EXPORTER_OTLP_METRIC_PERIOD",
+		"OTEL_EXPORTER_OTLP_METRIC_TEMPORALITY_PREFERENCE",
 		"LS_METRICS_ENABLED",
 	}
 	for _, envvar := range vars {

pipelines/common.go

@@ -14,7 +14,9 @@
 
 package pipelines
 
-import "go.opentelemetry.io/otel/sdk/resource"
+import (
+	"go.opentelemetry.io/otel/sdk/resource"
+)
 
 type PipelineConfig struct {
 	Endpoint        string
@@ -23,6 +25,9 @@ type PipelineConfig struct {
 	Resource        *resource.Resource
 	ReportingPeriod string
 	Propagators     []string
+
+	// TemporalityPreference is one of "cumulative", "delta", or "stateless"
+	TemporalityPreference string
 }
 
 type PipelineSetupFunc func(PipelineConfig) (func() error, error)