Avoid error logs in BenchmarkMultipleExportersToCollector (#323)

* Gracefully shutdown exporter connections before stopping collector.
* Do not log an error for graceful client shutdown (EOF error).

Signed-off-by: Antonin Bas <abas@vmware.com>

pkg/collector/process.go

@@ -383,7 +383,7 @@ func getMessageLength(reader *bufio.Reader) (int, error) {
 	var msgLen uint16
 	err = util.Decode(bytes.NewBuffer(partialHeader[2:]), binary.BigEndian, &msgLen)
 	if err != nil {
-		return 0, fmt.Errorf("cannot decode message: %v", err)
+		return 0, fmt.Errorf("cannot decode message: %w", err)
 	}
 	return int(msgLen), nil
 }

pkg/collector/tcp.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"crypto/tls"
 	"crypto/x509"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -70,25 +71,29 @@ func (cp *CollectingProcess) handleTCPClient(conn net.Conn) {
 		reader := bufio.NewReader(conn)
 		for {
 			length, err := getMessageLength(reader)
+			if errors.Is(err, io.EOF) {
+				klog.V(2).InfoS("Connection was closed by client")
+				return
+			}
 			if err != nil {
-				klog.Errorf("error when retrieving message length: %v", err)
+				klog.ErrorS(err, "Error when retrieving message length")
 				cp.deleteClient(address)
 				return
 			}
 			buff := make([]byte, length)
 			_, err = io.ReadFull(reader, buff)
 			if err != nil {
-				klog.Errorf("error when reading the message: %v", err)
+				klog.ErrorS(err, "Error when reading the message")
 				cp.deleteClient(address)
 				return
 			}
 			message, err := cp.decodePacket(bytes.NewBuffer(buff), address)
 			if err != nil {
-				klog.Error(err)
+				klog.ErrorS(err, "Error when decoding packet")
 				continue
 			}
-			klog.V(4).Infof("Processed message from exporter with observation domain ID: %v ser type: %v number of records: %v",
-				message.GetObsDomainID(), message.GetSet().GetSetType(), message.GetSet().GetNumberOfRecords())
+			klog.V(4).InfoS("Processed message from exporter",
+				"observationDomainID", message.GetObsDomainID(), "setType", message.GetSet().GetSetType(), "numRecords", message.GetSet().GetNumberOfRecords())
 		}
 	}()
 	<-cp.stopChan

pkg/test/collector_perf_test.go

@@ -71,6 +71,7 @@ func BenchmarkMultipleExportersToCollector(b *testing.B) {
 	}
 	go cp.Start()
 	waitForCollectorStatus(b, cp, true)
+	exporters := make([]*exporter.ExportingProcess, 0, numOfExporters)
 	b.ResetTimer()
 	for i := 0; i < numOfExporters; i++ {
 		b.StartTimer()
@@ -89,17 +90,25 @@ func BenchmarkMultipleExportersToCollector(b *testing.B) {
 			exporter.SendSet(createDataSet(templateID, true, false, false))
 		}
 		b.StopTimer()
+		exporters = append(exporters, exporter)
 		time.Sleep(time.Millisecond)
 	}
 	b.StartTimer()
 	count := 0
 	for range cp.GetMsgChan() {
 		count++
 		if count == numOfRecords*numOfExporters {
-			cp.Stop()
 			break
 		}
 	}
+	b.StopTimer()
+	// Gracefully shutdown all the exporters to avoid "use of closed network connection" error
+	// logs.
+	for i := 0; i < numOfExporters; i++ {
+		exporters[i].CloseConnToCollector()
+	}
+	b.StartTimer()
+	cp.Stop()
 	waitForCollectorStatus(b, cp, false)
 }