diff --git a/koa2/.babelrc b/koa2/.babelrc
index 370e802..e6a46dc 100644
--- a/koa2/.babelrc
+++ b/koa2/.babelrc
@@ -1,3 +1,3 @@
 {
-  "presets": ["es2015-node5","stage-3"]
-}
\ No newline at end of file
+  "presets": ["es2017-node7"]
+}
diff --git a/koa2/koa2-async-compile.js b/koa2/koa2-async-compile.js
index add8dfd..9d8277d 100644
--- a/koa2/koa2-async-compile.js
+++ b/koa2/koa2-async-compile.js
@@ -1,43 +1,39 @@
-
 'use strict';
 
-function _asyncToGenerator(fn) { return function () { var gen = fn.apply(this, arguments); return new Promise(function (resolve, reject) { function step(key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { return Promise.resolve(value).then(function (value) { return step("next", value); }, function (err) { return step("throw", err); }); } } return step("next"); }); }; }
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
 
-var http = require('http');
-var koa = require('koa');
-var app = new koa();
+var _http = require('http');
 
-// number of middleware
+var _http2 = _interopRequireDefault(_http);
+
+var _koa = require('koa');
+
+var _koa2 = _interopRequireDefault(_koa);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
 
-var n = parseInt(process.env.MW || '1', 10);
+const app = new _koa2.default();
+
+// number of middleware
+let n = parseInt(process.env.MW || '1', 10);
 console.log('  %s async middleware', n);
 
 while (n--) {
-  app.use((() => {
-    var ref = _asyncToGenerator(function* (ctx, next) {
-      yield next();
-    });
-
-    return function (_x, _x2) {
-      return ref.apply(this, arguments);
-    };
-  })());
+  app.use(async (ctx, next) => {
+    await next();
+  });
 }
 
-var body = new Buffer('Hello World');
-
-app.use((() => {
-  var ref = _asyncToGenerator(function* (ctx, next) {
-    yield next();
-    ctx.body = body;
-  });
+const body = new Buffer('Hello World');
 
-  return function (_x3, _x4) {
-    return ref.apply(this, arguments);
-  };
-})());
+app.use(async (ctx, next) => {
+  await next();
+  ctx.body = body;
+});
 
 // var apprequire('./koa2-async.js')
 app.listen(3333);
 
-module.exports = app;
+exports.default = app;
diff --git a/koa2/koa2-async.js b/koa2/koa2-async.js
index 6393837..06c3c2c 100755
--- a/koa2/koa2-async.js
+++ b/koa2/koa2-async.js
@@ -1,31 +1,28 @@
 
-'use strict';
-
-var http = require('http');
-var koa = require('koa');
-var app = new koa();
+import http from 'http'
+import Koa from 'koa'
 
+const app = new Koa()
 
 // number of middleware
-
-var n = parseInt(process.env.MW || '1', 10);
-console.log('  %s async middleware', n);
+let n = parseInt(process.env.MW || '1', 10)
+console.log('  %s async middleware', n)
 
 while (n--) {
   app.use(async (ctx, next) => {
-    await next();
-  });
+    await next()
+  })
 }
 
-var body = new Buffer('Hello World');
+const body = new Buffer('Hello World')
 
 app.use(async (ctx, next) => {
-  await next();
-  ctx.body = body;
-});
+  await next()
+  ctx.body = body
+})
 
 
 // var apprequire('./koa2-async.js')
-app.listen(3333);
+app.listen(3333)
 
-module.exports = app
+export default app
diff --git a/koa2/package.json b/koa2/package.json
index 051f4a1..d65e2a4 100644
--- a/koa2/package.json
+++ b/koa2/package.json
@@ -19,10 +19,6 @@
   "devDependencies": {
     "babel-cli": "^6.7.5",
     "babel-core": "^6.7.5",
-    "babel-plugin-add-module-exports": "^0.1.2",
-    "babel-plugin-transform-es2015-modules-commonjs": "^6.7.4",
-    "babel-polyfill": "^6.1.4",
-    "babel-preset-es2015-node5": "^1.2.0",
-    "babel-preset-stage-3": "^6.5.0"
+    "babel-preset-es2017-node7": "^0.3.0"
   }
 }
diff --git a/logs/wrk_result.json b/logs/wrk_result.json
index 7312088..90a25ad 100644
--- a/logs/wrk_result.json
+++ b/logs/wrk_result.json
@@ -5,18 +5,18 @@
         "port": "3333",
         "threads": "8",
         "connections": "50",
-        "latency_avg": "10.72",
-        "latency_stdev": "3.40",
-        "latency_max": "51.43",
-        "latency_precent": "93.00%",
-        "req_per_second_avg": "569.64",
-        "req_per_second_stdev": "107.73",
-        "req_per_second_max": "770.00  ",
-        "req_per_second_precent": "87.50%",
-        "requests_count": "13641",
+        "latency_avg": "11.02",
+        "latency_stdev": "5.67",
+        "latency_max": "54.13",
+        "latency_precent": "87.75%",
+        "req_per_second_avg": "568.74",
+        "req_per_second_stdev": "126.03",
+        "req_per_second_max": "740.00  ",
+        "req_per_second_precent": "77.92%",
+        "requests_count": "13617",
         "requests_seconds": "3.01s",
         "requests_read": "2.73MB",
-        "requests_per_sec": "4526.00",
+        "requests_per_sec": "4522.65",
         "transfer_per_sec": "0.91M"
     },
     "koa1.js": {
@@ -25,19 +25,19 @@
         "port": "3333",
         "threads": "8",
         "connections": "50",
-        "latency_avg": "10.04",
-        "latency_stdev": "3.48",
-        "latency_max": "42.47",
-        "latency_precent": "89.97%",
-        "req_per_second_avg": "607.86",
-        "req_per_second_stdev": "188.15",
-        "req_per_second_max": "2.23k ",
-        "req_per_second_precent": "92.56%",
-        "requests_count": "14664",
+        "latency_avg": "10.96",
+        "latency_stdev": "5.30",
+        "latency_max": "54.11",
+        "latency_precent": "85.40%",
+        "req_per_second_avg": "564.54",
+        "req_per_second_stdev": "170.20",
+        "req_per_second_max": "1.62k ",
+        "req_per_second_precent": "90.95%",
+        "requests_count": "13669",
         "requests_seconds": "3.10s",
-        "requests_read": "2.11MB",
-        "requests_per_sec": "4723.93",
-        "transfer_per_sec": "696.60K"
+        "requests_read": "1.97MB",
+        "requests_per_sec": "4405.32",
+        "transfer_per_sec": "649.61K"
     },
     "koa2-async-compile.js": {
         "time": "3",
@@ -45,19 +45,19 @@
         "port": "3333",
         "threads": "8",
         "connections": "50",
-        "latency_avg": "22.57",
-        "latency_stdev": "5.68",
-        "latency_max": "73.34",
-        "latency_precent": "94.58%",
-        "req_per_second_avg": "268.37",
-        "req_per_second_stdev": "48.76",
-        "req_per_second_max": "333.00  ",
-        "req_per_second_precent": "90.83%",
-        "requests_count": "6447",
-        "requests_seconds": "3.03s",
-        "requests_read": "0.93MB",
-        "requests_per_sec": "2129.67",
-        "transfer_per_sec": "314.04K"
+        "latency_avg": "16.74",
+        "latency_stdev": "6.92",
+        "latency_max": "62.26",
+        "latency_precent": "88.88%",
+        "req_per_second_avg": "366.57",
+        "req_per_second_stdev": "74.74",
+        "req_per_second_max": "484.00  ",
+        "req_per_second_precent": "80.83%",
+        "requests_count": "8779",
+        "requests_seconds": "3.01s",
+        "requests_read": "1.26MB",
+        "requests_per_sec": "2914.67",
+        "transfer_per_sec": "429.80K"
     },
     "koa2.js": {
         "time": "3",
@@ -65,18 +65,18 @@
         "port": "3333",
         "threads": "8",
         "connections": "50",
-        "latency_avg": "8.85",
-        "latency_stdev": "2.94",
-        "latency_max": "42.26",
-        "latency_precent": "88.21%",
-        "req_per_second_avg": "688.38",
-        "req_per_second_stdev": "213.02",
-        "req_per_second_max": "2.71k ",
-        "req_per_second_precent": "92.15%",
-        "requests_count": "16609",
+        "latency_avg": "7.07",
+        "latency_stdev": "4.01",
+        "latency_max": "48.51",
+        "latency_precent": "88.19%",
+        "req_per_second_avg": "0.90k",
+        "req_per_second_stdev": "250.80",
+        "req_per_second_max": "1.99k ",
+        "req_per_second_precent": "88.52%",
+        "requests_count": "21852",
         "requests_seconds": "3.10s",
-        "requests_read": "2.39MB",
-        "requests_per_sec": "5353.28",
-        "transfer_per_sec": "789.40K"
+        "requests_read": "3.15MB",
+        "requests_per_sec": "7042.91",
+        "transfer_per_sec": "1.01M"
     }
 }
\ No newline at end of file
diff --git a/logs/wrk_result04-20.json b/logs/wrk_result04-20.json
new file mode 100644
index 0000000..7312088
--- /dev/null
+++ b/logs/wrk_result04-20.json
@@ -0,0 +1,82 @@
+{
+    "express.js": {
+        "time": "3",
+        "host": "localhost",
+        "port": "3333",
+        "threads": "8",
+        "connections": "50",
+        "latency_avg": "10.72",
+        "latency_stdev": "3.40",
+        "latency_max": "51.43",
+        "latency_precent": "93.00%",
+        "req_per_second_avg": "569.64",
+        "req_per_second_stdev": "107.73",
+        "req_per_second_max": "770.00  ",
+        "req_per_second_precent": "87.50%",
+        "requests_count": "13641",
+        "requests_seconds": "3.01s",
+        "requests_read": "2.73MB",
+        "requests_per_sec": "4526.00",
+        "transfer_per_sec": "0.91M"
+    },
+    "koa1.js": {
+        "time": "3",
+        "host": "localhost",
+        "port": "3333",
+        "threads": "8",
+        "connections": "50",
+        "latency_avg": "10.04",
+        "latency_stdev": "3.48",
+        "latency_max": "42.47",
+        "latency_precent": "89.97%",
+        "req_per_second_avg": "607.86",
+        "req_per_second_stdev": "188.15",
+        "req_per_second_max": "2.23k ",
+        "req_per_second_precent": "92.56%",
+        "requests_count": "14664",
+        "requests_seconds": "3.10s",
+        "requests_read": "2.11MB",
+        "requests_per_sec": "4723.93",
+        "transfer_per_sec": "696.60K"
+    },
+    "koa2-async-compile.js": {
+        "time": "3",
+        "host": "localhost",
+        "port": "3333",
+        "threads": "8",
+        "connections": "50",
+        "latency_avg": "22.57",
+        "latency_stdev": "5.68",
+        "latency_max": "73.34",
+        "latency_precent": "94.58%",
+        "req_per_second_avg": "268.37",
+        "req_per_second_stdev": "48.76",
+        "req_per_second_max": "333.00  ",
+        "req_per_second_precent": "90.83%",
+        "requests_count": "6447",
+        "requests_seconds": "3.03s",
+        "requests_read": "0.93MB",
+        "requests_per_sec": "2129.67",
+        "transfer_per_sec": "314.04K"
+    },
+    "koa2.js": {
+        "time": "3",
+        "host": "localhost",
+        "port": "3333",
+        "threads": "8",
+        "connections": "50",
+        "latency_avg": "8.85",
+        "latency_stdev": "2.94",
+        "latency_max": "42.26",
+        "latency_precent": "88.21%",
+        "req_per_second_avg": "688.38",
+        "req_per_second_stdev": "213.02",
+        "req_per_second_max": "2.71k ",
+        "req_per_second_precent": "92.15%",
+        "requests_count": "16609",
+        "requests_seconds": "3.10s",
+        "requests_read": "2.39MB",
+        "requests_per_sec": "5353.28",
+        "transfer_per_sec": "789.40K"
+    }
+}
\ No newline at end of file
diff --git a/run b/run
index e3ff2b3..b0a2022 100755
--- a/run
+++ b/run
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 echo
-MW=$1 node $2 &
+MW=$1 node --harmony $2 &
 pid=$!
 
 sleep 2
diff --git a/run2 b/run2
index b010e4f..c4e94dc 100755
--- a/run2
+++ b/run2
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 echo
-MW=$1 node $2 &
+MW=$1 node --harmony $2 &
 pid=$!
 
 sleep 2