add p2c peak ewma load balancer

example/graceful/etcd/api/handler/gracefulhandler.go

@@ -18,20 +18,13 @@ import (
 func gracefulHandler(ctx *svc.ServiceContext) http.HandlerFunc {
 	logger := executors.NewLessExecutor(time.Second)
 	return func(w http.ResponseWriter, r *http.Request) {
-		var resp types.Response
-
-		conn, ok := ctx.Client.Next()
-		if !ok {
-			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-			return
-		}
-
 		host, err := os.Hostname()
 		if err != nil {
 			http.Error(w, http.StatusText(http.StatusNotImplemented), http.StatusNotImplemented)
 			return
 		}
 
+		conn := ctx.Client.Conn()
 		client := graceful.NewGraceServiceClient(conn)
 		rp, err := client.Grace(context.Background(), &graceful.Request{From: host})
 		if err != nil {
@@ -40,6 +33,7 @@ func gracefulHandler(ctx *svc.ServiceContext) http.HandlerFunc {
 			return
 		}
 
+		var resp types.Response
 		resp.Host = rp.Host
 		logger.DoOrDiscard(func() {
 			fmt.Printf("%s from host: %s\n", time.Now().Format("15:04:05"), rp.Host)