diff --git a/app.js b/app.js
index b64f69f..c41870c 100644
--- a/app.js
+++ b/app.js
@@ -175,6 +175,6 @@ exports.useMiddleware = useMiddleware;
 exports.registerDb = registerDb;
 exports.getDbConn = getDbConn;
 exports.addStaticDirectory = addStaticDirectory;
-exports.getNodeId = getPid;
+exports.getPid = getPid;
 exports.getNodeId = getNodeId;
 exports.getInstanceId = getInstanceId;
diff --git a/utils.js b/utils.js
index f831ff4..414e003 100644
--- a/utils.js
+++ b/utils.js
@@ -351,7 +351,7 @@ function safeDumpErrStack(err) {
 }
 
 function normalMd5UrlSign(params, $secretKey) {
-  const sortedKeys = params.keys().sort();
+  const sortedKeys = Object.keys(params).sort();
   const connStr = '&';
   let paramsStr = '';
   sortedKeys.forEach