Fix missing shutdown of the batch processor (open-telemetry#1186)

Signed-off-by: Hui Kang <kangh@us.ibm.com>

Co-authored-by: Anthony Mirabella <a9@aneurysm9.com>

CHANGELOG.md

@@ -49,6 +49,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Fixed
 
 - Zipkin example no longer mentions `ParentSampler`, corrected to `ParentBased`. (#1171)
+- Fix missing shutdown processor in otel-collector example. (#1186)
 
 ## [0.11.0] - 2020-08-24
 

example/otel-collector/main.go

@@ -40,7 +40,7 @@ import (
 
 // Initializes an OTLP exporter, and configures the corresponding trace and
 // metric providers.
-func initProvider() (*otlp.Exporter, *push.Controller) {
+func initProvider() func() {
 
 	// If the OpenTelemetry Collector is running on a local cluster (minikube or
 	// microk8s), it should be accessible through the NodePort service at the
@@ -54,13 +54,14 @@ func initProvider() (*otlp.Exporter, *push.Controller) {
 	)
 	handleErr(err, "failed to create exporter")
 
+	bsp := sdktrace.NewBatchSpanProcessor(exp)
 	tracerProvider := sdktrace.NewProvider(
 		sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
 		sdktrace.WithResource(resource.New(
 			// the service name used to display traces in backends
 			semconv.ServiceNameKey.String("test-service"),
 		)),
-		sdktrace.WithBatcher(exp),
+		sdktrace.WithSpanProcessor(bsp),
 	)
 
 	pusher := push.New(
@@ -76,17 +77,18 @@ func initProvider() (*otlp.Exporter, *push.Controller) {
 	global.SetMeterProvider(pusher.Provider())
 	pusher.Start()
 
-	return exp, pusher
+	return func() {
+		bsp.Shutdown() // shutdown the processor
+		handleErr(exp.Shutdown(context.Background()), "failed to stop exporter")
+		pusher.Stop() // pushes any last exports to the receiver
+	}
 }
 
 func main() {
 	log.Printf("Waiting for connection...")
 
-	exp, pusher := initProvider()
-	defer func() {
-		handleErr(exp.Shutdown(context.Background()), "failed to stop exporter")
-	}()
-	defer pusher.Stop() // pushes any last exports to the receiver
+	shutdown := initProvider()
+	defer shutdown()
 
 	tracer := global.Tracer("test-tracer")
 	meter := global.Meter("test-meter")
@@ -112,6 +114,7 @@ func main() {
 		context.Background(),
 		"CollectorExporter-Example",
 		apitrace.WithAttributes(commonLabels...))
+	defer span.End()
 	for i := 0; i < 10; i++ {
 		_, iSpan := tracer.Start(ctx, fmt.Sprintf("Sample-%d", i))
 		log.Printf("Doing really hard work (%d / 10)\n", i+1)
@@ -122,7 +125,6 @@ func main() {
 	}
 
 	log.Printf("Done!")
-	span.End()
 }
 
 func handleErr(err error, message string) {