diff --git a/stress/client/main.go b/stress/client/main.go
index 0568c459..bb665e98 100644
--- a/stress/client/main.go
+++ b/stress/client/main.go
@@ -69,16 +69,16 @@ type testCaseWithWeight struct {
 }
 
 // parseTestCases converts test case string to a list of struct testCaseWithWeight.
-func parseTestCases(testCaseString string) ([]testCaseWithWeight, error) {
+func parseTestCases(testCaseString string) []testCaseWithWeight {
 	testCaseStrings := strings.Split(testCaseString, ",")
 	testCases := make([]testCaseWithWeight, len(testCaseStrings))
 	for i, str := range testCaseStrings {
-		temp := strings.Split(str, ":")
-		if len(temp) < 2 {
-			return nil, fmt.Errorf("invalid test case with weight: %s", str)
+		testCase := strings.Split(str, ":")
+		if len(testCase) != 2 {
+			panic(fmt.Sprintf("invalid test case with weight: %s", str))
 		}
 		// Check if test case is supported.
-		switch temp[0] {
+		switch testCase[0] {
 		case
 			"empty_unary",
 			"large_unary",
@@ -86,16 +86,16 @@ func parseTestCases(testCaseString string) ([]testCaseWithWeight, error) {
 			"server_streaming",
 			"empty_stream":
 		default:
-			return nil, fmt.Errorf("unknown test type: %s", temp[0])
+			panic(fmt.Sprintf("unknown test type: %s", testCase[0]))
 		}
-		testCases[i].name = temp[0]
-		w, err := strconv.Atoi(temp[1])
+		testCases[i].name = testCase[0]
+		w, err := strconv.Atoi(testCase[1])
 		if err != nil {
-			return nil, fmt.Errorf("%v", err)
+			panic(fmt.Sprintf("%v", err))
 		}
 		testCases[i].weight = w
 	}
-	return testCases, nil
+	return testCases
 }
 
 // weightedRandomTestSelector defines a weighted random selector for test case types.
@@ -114,25 +114,24 @@ func newWeightedRandomTestSelector(tests []testCaseWithWeight) *weightedRandomTe
 	return &weightedRandomTestSelector{tests, totalWeight}
 }
 
-func (selector weightedRandomTestSelector) getNextTest() (string, error) {
+func (selector weightedRandomTestSelector) getNextTest() string {
 	random := rand.Intn(selector.totalWeight)
 	var weightSofar int
 	for _, test := range selector.tests {
 		weightSofar += test.weight
 		if random < weightSofar {
-			return test.name, nil
+			return test.name
 		}
 	}
-	return "", fmt.Errorf("no test case selected by weightedRandomTestSelector")
+	panic("no test case selected by weightedRandomTestSelector")
 }
 
-// gauge defines type for gauge.
+// gauge stores the qps of one interop client (one stub).
 type gauge struct {
 	mutex sync.RWMutex
 	val   int64
 }
 
-// Set updates the gauge value
 func (g *gauge) set(v int64) {
 	g.mutex.Lock()
 	defer g.mutex.Unlock()
@@ -145,9 +144,10 @@ func (g *gauge) get() int64 {
 	return g.val
 }
 
-// Server implements metrics server functions.
+// server implements metrics server functions.
 type server struct {
-	mutex  sync.RWMutex
+	mutex sync.RWMutex
+	// gauges is a map from /stress_test/server_<n>/channel_<n>/stub_<n>/qps to its qps gauge.
 	gauges map[string]*gauge
 }
 
@@ -162,8 +162,7 @@ func (s *server) GetAllGauges(in *metricspb.EmptyMessage, stream metricspb.Metri
 	defer s.mutex.RUnlock()
 
 	for name, gauge := range s.gauges {
-		err := stream.Send(&metricspb.GaugeResponse{Name: name, Value: &metricspb.GaugeResponse_LongValue{gauge.get()}})
-		if err != nil {
+		if err := stream.Send(&metricspb.GaugeResponse{Name: name, Value: &metricspb.GaugeResponse_LongValue{gauge.get()}}); err != nil {
 			return err
 		}
 	}
@@ -181,19 +180,18 @@ func (s *server) GetGauge(ctx context.Context, in *metricspb.GaugeRequest) (*met
 	return nil, grpc.Errorf(codes.InvalidArgument, "gauge with name %s not found", in.Name)
 }
 
-// CreateGauge creates a guage using the given name in metrics server
-func (s *server) createGauge(name string) (*gauge, error) {
+// createGauge creates a guage using the given name in metrics server.
+func (s *server) createGauge(name string) *gauge {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 
-	grpclog.Printf("create gauge: %s", name)
 	if _, ok := s.gauges[name]; ok {
 		// gauge already exists.
-		return nil, fmt.Errorf("gauge %s already exists", name)
+		panic(fmt.Sprintf("gauge %s already exists", name))
 	}
 	var g gauge
 	s.gauges[name] = &g
-	return &g, nil
+	return &g
 }
 
 func startServer(server *server, port int) {
@@ -208,57 +206,35 @@ func startServer(server *server, port int) {
 
 }
 
-// stressClient defines client for stress test.
-type stressClient struct {
-	testID        int
-	address       string
-	selector      *weightedRandomTestSelector
-	interopClient testpb.TestServiceClient
-	stop          <-chan bool
-}
-
-// newStressClient construct a new stressClient.
-func newStressClient(id int, addr string, conn *grpc.ClientConn, selector *weightedRandomTestSelector, stop <-chan bool) *stressClient {
+// performRPCs uses weightedRandomTestSelector to select test case and runs the tests.
+func performRPCs(gauge *gauge, conn *grpc.ClientConn, selector *weightedRandomTestSelector, stop <-chan bool) {
 	client := testpb.NewTestServiceClient(conn)
-	return &stressClient{testID: id, address: addr, selector: selector, interopClient: client, stop: stop}
-}
-
-// mainLoop uses weightedRandomTestSelector to select test case and runs the tests.
-func (c *stressClient) mainLoop(gauge *gauge) {
 	var numCalls int64
-	timeStarted := time.Now()
+	startTime := time.Now()
 	for {
-		done := make(chan bool)
+		done := make(chan bool, 1)
 		go func() {
-			test, err := c.selector.getNextTest()
-			if err != nil {
-				grpclog.Printf("%v", err)
-				done <- false
-			}
+			test := selector.getNextTest()
 			switch test {
 			case "empty_unary":
-				interop.DoEmptyUnaryCall(c.interopClient)
+				interop.DoEmptyUnaryCall(client)
 			case "large_unary":
-				interop.DoLargeUnaryCall(c.interopClient)
+				interop.DoLargeUnaryCall(client)
 			case "client_streaming":
-				interop.DoClientStreaming(c.interopClient)
+				interop.DoClientStreaming(client)
 			case "server_streaming":
-				interop.DoServerStreaming(c.interopClient)
+				interop.DoServerStreaming(client)
 			case "empty_stream":
-				interop.DoEmptyStream(c.interopClient)
-			default:
-				grpclog.Fatalf("Unsupported test case: %d", test)
+				interop.DoEmptyStream(client)
 			}
 			done <- true
 		}()
 		select {
-		case <-c.stop:
+		case <-stop:
 			return
-		case r := <-done:
-			if r {
-				numCalls++
-				gauge.set(int64(float64(numCalls) / time.Since(timeStarted).Seconds()))
-			}
+		case <-done:
+			numCalls++
+			gauge.set(int64(float64(numCalls) / time.Since(startTime).Seconds()))
 		}
 	}
 }
@@ -284,10 +260,7 @@ func logParameterInfo(addresses []string, tests []testCaseWithWeight) {
 func main() {
 	flag.Parse()
 	addresses := strings.Split(*serverAddresses, ",")
-	tests, err := parseTestCases(*testCases)
-	if err != nil {
-		grpclog.Fatalf("%v\n", err)
-	}
+	tests := parseTestCases(*testCases)
 	logParameterInfo(addresses, tests)
 	testSelector := newWeightedRandomTestSelector(tests)
 	metricsServer := newMetricsServer()
@@ -296,7 +269,6 @@ func main() {
 	wg.Add(len(addresses) * *numChannelsPerServer * *numStubsPerChannel)
 	stop := make(chan bool)
 
-	var clientIndex int
 	for serverIndex, address := range addresses {
 		for connIndex := 0; connIndex < *numChannelsPerServer; connIndex++ {
 			conn, err := grpc.Dial(address, grpc.WithInsecure())
@@ -304,17 +276,12 @@ func main() {
 				grpclog.Fatalf("Fail to dial: %v", err)
 			}
 			defer conn.Close()
-			for stubIndex := 0; stubIndex < *numStubsPerChannel; stubIndex++ {
-				clientIndex++
-				client := newStressClient(clientIndex, address, conn, testSelector, stop)
-				buf := fmt.Sprintf("/stress_test/server_%d/channel_%d/stub_%d/qps", serverIndex+1, connIndex+1, stubIndex+1)
+			for clientIndex := 0; clientIndex < *numStubsPerChannel; clientIndex++ {
+				name := fmt.Sprintf("/stress_test/server_%d/channel_%d/stub_%d/qps", serverIndex+1, connIndex+1, clientIndex+1)
 				go func() {
 					defer wg.Done()
-					if g, err := metricsServer.createGauge(buf); err != nil {
-						grpclog.Fatalf("%v", err)
-					} else {
-						client.mainLoop(g)
-					}
+					g := metricsServer.createGauge(name)
+					performRPCs(g, conn, testSelector, stop)
 				}()
 			}
 
diff --git a/stress/metrics_client/main.go b/stress/metrics_client/main.go
index fbce662c..983a8ff2 100644
--- a/stress/metrics_client/main.go
+++ b/stress/metrics_client/main.go
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2014, Google Inc.
+ * Copyright 2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -35,8 +35,8 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"io"
-	"time"
 
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
@@ -45,54 +45,53 @@ import (
 )
 
 var (
-	metricsServerAddressPtr = flag.String("metrics_server_address", "", "The metrics server addresses in the fomrat <hostname>:<port>")
-	totalOnlyPtr            = flag.Bool("total_only", false, "If true, this prints only the total value of all gauges")
+	metricsServerAddress = flag.String("metrics_server_address", "", "The metrics server addresses in the fomrat <hostname>:<port>")
+	totalOnly            = flag.Bool("total_only", false, "If true, this prints only the total value of all gauges")
 )
 
-const timeoutSeconds = 10
-
 func printMetrics(client metricspb.MetricsServiceClient, totalOnly bool) {
-	ctx, _ := context.WithTimeout(context.Background(), timeoutSeconds*time.Second)
-	stream, err := client.GetAllGauges(ctx, &metricspb.EmptyMessage{})
+	stream, err := client.GetAllGauges(context.Background(), &metricspb.EmptyMessage{})
 	if err != nil {
 		grpclog.Fatalf("failed to call GetAllGuages: %v", err)
 	}
 
-	var overallQPS int64
-	var rpcStatus error
+	var (
+		overallQPS int64
+		rpcStatus  error
+	)
 	for {
 		gaugeResponse, err := stream.Recv()
 		if err != nil {
 			rpcStatus = err
 			break
 		}
-		if _, ok := gaugeResponse.GetValue().(*metricspb.GaugeResponse_LongValue); ok {
-			if !totalOnly {
-				grpclog.Printf("%s: %d", gaugeResponse.Name, gaugeResponse.GetLongValue())
-			}
-			overallQPS += gaugeResponse.GetLongValue()
-		} else {
-			grpclog.Printf("gauge %s is not a long value", gaugeResponse.Name)
+		if _, ok := gaugeResponse.GetValue().(*metricspb.GaugeResponse_LongValue); !ok {
+			panic(fmt.Sprintf("gauge %s is not a long value", gaugeResponse.Name))
 		}
+		v := gaugeResponse.GetLongValue()
+		if !totalOnly {
+			grpclog.Printf("%s: %d", gaugeResponse.Name, v)
+		}
+		overallQPS += v
 	}
-	grpclog.Printf("overall qps: %d", overallQPS)
 	if rpcStatus != io.EOF {
 		grpclog.Fatalf("failed to finish server streaming: %v", rpcStatus)
 	}
+	grpclog.Printf("overall qps: %d", overallQPS)
 }
 
 func main() {
 	flag.Parse()
-	if len(*metricsServerAddressPtr) == 0 {
-		grpclog.Fatalf("Cannot connect to the Metrics server. Please pass the address of the metrics server to connect to via the 'metrics_server_address' flag")
+	if *metricsServerAddress == "" {
+		grpclog.Fatalf("Metrics server address is empty.")
 	}
 
-	conn, err := grpc.Dial(*metricsServerAddressPtr, grpc.WithInsecure())
+	conn, err := grpc.Dial(*metricsServerAddress, grpc.WithInsecure())
 	if err != nil {
 		grpclog.Fatalf("cannot connect to metrics server: %v", err)
 	}
 	defer conn.Close()
 
 	c := metricspb.NewMetricsServiceClient(conn)
-	printMetrics(c, *totalOnlyPtr)
+	printMetrics(c, *totalOnly)
 }