Warn client when invocation fail.

Before the relay panics when the function did
not repond in time or something breaks.
Instead of breaking we send back a waring to the
invoking client.

Signed-off-by: David Schall <[email protected]>

tools/relay/server.go

@@ -61,6 +61,10 @@ var (
 	value           = flag.String("value", "helloWorld", "String input to pass to benchmark")
 	functionMethod  = flag.String("function-method", "default", "Which method of benchmark to invoke")
 
+	clientReqRecv  = 0
+	funcInvSuccess = 0
+	funcInvFail    = 0
+
 	// Client
 	grpcClient     grpcClients.GrpcClient
 	inputGenerator grpcClients.Generator
@@ -77,6 +81,11 @@ func isDebuggingEnabled() bool {
 	}
 }
 
+func printStats() {
+	log.Printf("Client Requests: %d", clientReqRecv)
+	log.Printf("Function Invocations: %d successful, %d fail", funcInvSuccess, funcInvFail)
+}
+
 func main() {
 	flag.Parse()
 
@@ -139,17 +148,29 @@ func main() {
 	log.Printf("Started relay server at %s", *address)
 
 	if err := grpcServer.Serve(listener); err != nil {
-		log.Fatalf("failed to serve: %v", err)
+		log.Fatalf("Failed to serve: %v", err)
 	}
 }
 
 func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
-	log.Info("Received from invoker: ", in.GetName())
+	log.Debug("Received from invoker: ", in.GetName())
+	clientReqRecv++
+
+	if clientReqRecv%100 == 0 {
+		printStats()
+	}
 
 	// Create new packet
 	pkt := inputGenerator.Next()
 	log.Debug("Send to func: ", pkt)
-	reply := grpcClient.Request(ctx, pkt)
+	reply, err := grpcClient.Request(ctx, pkt)
+	if err != nil {
+		log.Warnf("Failed to send request to function: %v\n", err)
+		funcInvFail++
+		return nil, err
+	}
+
+	funcInvSuccess++
 	log.Debug("Recv from func: ", reply)
 
 	return &pb.HelloReply{Message: reply}, nil