diff --git a/conf/docklet.conf.template b/conf/docklet.conf.template
index 01f2e23..e9c838b 100644
--- a/conf/docklet.conf.template
+++ b/conf/docklet.conf.template
@@ -178,3 +178,7 @@
 # The two ports next to '-' are inclueded. If there are several ranges,
 # Please seperate them by ',' , for example: 10000-20000,30000-40000
 # ALLOCATED_PORTS=10000-65535
+
+# ALLOW_SCALE_OUT: allow docklet to rent server on the cloud to scale out
+# Only when you deploy docklet on the cloud can you set it to True
+# ALLOW_SCALE_OUT=False
diff --git a/src/cloudmgr.py b/src/cloudmgr.py
index 936616d..2b8957a 100755
--- a/src/cloudmgr.py
+++ b/src/cloudmgr.py
@@ -162,6 +162,11 @@ class AliyunMgr():
         thread.setDaemon(True)
         thread.start()
 
+class EmptyMgr():
+    def addNodeAsync(self):
+        logger.error("current cluster does not support scale out")
+        return False
+
 class CloudMgr():
     
     def getSettingFile(self):
@@ -185,4 +190,7 @@ class CloudMgr():
 
 
     def __init__(self):
-        self.engine = AliyunMgr()
+        if env.getenv("ALLOW_SCALE_OUT") == "True":
+            self.engine = AliyunMgr()
+        else:
+            self.engine = EmptyMgr()
diff --git a/src/env.py b/src/env.py
index 87ae996..3fcc8d1 100755
--- a/src/env.py
+++ b/src/env.py
@@ -77,5 +77,7 @@ def getenv(key):
         return os.environ.get("APPROVAL_RBT","ON")
     elif key =="ALLOCATED_PORTS":
         return os.environ.get("ALLOCATED_PORTS","10000-65535")
+    elif key =="ALLOW_SCALE_OUT":
+        return os.environ.get("ALLOW_SCALE_OUT", "False")
     else:
         return os.environ.get(key,"")