diff --git a/.gitignore b/.gitignore
index 3683826..b451985 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,7 +7,6 @@ build.sh
 .DS_Store
 *.*~
 *.log
-
 cup/net/async/msgcenter_dict.py
-
 cup.tar
+tmp
diff --git a/ChangeLog b/ChangeLog
index 86fd5fb..de1d1e5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,27 @@
+Version 1.6.0 - Under development, not released yet.  starting from 2017.9.6 ~ 
+    * [Enhancement] cup.mail enhanced for analyzing cc and bcc lists.                                                           
+                                                                                                                   
+Version 1.5.6 - starting from  2017.3.1 ~ 2017.9.5                                                                 
+    * [Enhancement] async enhancement for stability                                                                
+    * [New] CycleIDGenerator for generating universally unique_id (ip, port                         
+        encoded as part of the id)                                                                                 
+    * [Enhancement] cup.net.async exits more quickly than before                                                   
+    * [Bug] cup.net.async - Fix CPU-utilization too high bug                                                       
+    * [Bug] cup.net.async - Fix getting-peerinfo bug                                                               
+    * [Bug] cup.res.linux - Kernel version was returned with a tuple                                
+        ('2', '6', '32') which should be (2, 6, 32)                                                                
+                                                                                                                   
+Version: 1.5.5 - staring from 11.18 ~ 2017.3.1                                                                                                                                                                
+    * [Enhancement] debug method for executor                                                                      
+    * [async] CNeedAckMsg & retry mechnism added. CAckMsg added                                                    
+                                                                                                                   
+Version: 1.5.4 - Starting from 2016.9 ~ 2016.11.11                                                                 
+    * [Enhancement] generator supports staring point                                                               
+    * [Enhancement] catch exception socket.gaierror when it encounters network                      
+        instability                                                                                                
+    * [Bug] Set up splitter other thant colon in a Configure2Dict with blanks and comments          
+    * [Async] Support automatic msg retry                                                                          
+    * [Async] Support ack msg       
 
 Version: 1.5.1                                                                                      
     * [New] cup.log - add xxx_if                                                                    
diff --git a/cup/mail.py b/cup/mail.py
index c148000..3f55475 100644
--- a/cup/mail.py
+++ b/cup/mail.py
@@ -254,7 +254,7 @@ def sendmail(self, recipients, subject='', body='', attachments=None,
             if type(cc) == str:
                 outer['Cc'] = cc
                 toaddrs.append(cc)
-            elif type(cc) == list:
+            elif isinstance(cc, list):
                 outer['Cc'] = self._COMMA_SPLITTER.join(cc)
                 toaddrs.extend(cc)
             else:
@@ -263,7 +263,7 @@ def sendmail(self, recipients, subject='', body='', attachments=None,
             if type(bcc) == str:
                 outer['Bcc'] = bcc
                 toaddrs.append(bcc)
-            elif type(bcc) == list:
+            elif isinstance(bcc, list):
                 outer['Bcc'] = self._COMMA_SPLITTER.join(bcc)
                 toaddrs.extend(bcc)
             else:
diff --git a/cup/services/msgbroker.py b/cup/services/msgbroker.py
index 3cc45e1..f5b1b91 100644
--- a/cup/services/msgbroker.py
+++ b/cup/services/msgbroker.py
@@ -11,7 +11,7 @@
 :description:
     Msg Broker Service. Every component of a process can produce_msg
 """
-from cup import decorators
+# from cup import decorators
 
 
 MSG_ERROR_DISK_ERROR = 1
@@ -19,19 +19,25 @@
 __all__ = ['BrokerCenter']
 
 
+MSG_TYPE_FATAL = 0
+MSG_TYPE_WARN = 1
+
+
 class BaseBroker(object):
     """
     Base Broker for a system
     """
+    _name = None
+    def __init__(self, name):
+        self._name = name
 
 
-@decorators.Singleton
 class BrokerCenter(BaseBroker):
     """
     Errmsg broker center
     """
     def __init__(self, name):
-        self._name = name
+        BaseBroker.__init__(self, name)
 
     def produce_msg(self, msg_type, extra_info, error):
         """register msg"""
@@ -42,4 +48,60 @@ def comsume_msg(self, msg_type):
         """
 
 
+class SystemErrmsgBroker(BrokerCenter):
+    """
+    system errmsg broker, you can use it to determine whether
+    exiting from the system is on the way
+    """
+    def __init__(self, name):
+        BrokerCenter.__init__(self, name)
+
+    def need_stop(self, path):
+        """
+        return True if the system registered on
+            the path needs to stop immediately
+        """
+
+    def fatal_alert(self, path, msg, need_stop=True):
+        """fatal alert systems"""
+
+    def warnning_alert(self, path, msg):
+        """
+        warnning alert
+        """
+
+    def register_msg(self, path, msgtype, msg):
+        """register msg into the system"""
+
+    def get_fatal_alerts(self, path):
+        """
+        get fatal alerts of the current running round
+        """
+
+    def clean_data(self, path, exclude_msgtypes=None):
+        """
+        clean data of the remaining data
+        """
+
+    def register_wakeup(self, path, msgtype, alert_cap_num, callfunc):
+        """
+        register wakeups.
+
+        :param alert_cap_num:
+            If alert_cap_num is 0, whenever a msg of msgtype is received,
+            the callfunc will be called.
+        :param msgtype:
+            [msgbroker.FATAL|msgbroker.WARN]
+        """
+
+    def _wakeup(self, path, msgtype, alert_cap_num, callfunc):
+        """
+        wake up callfunc
+        """
+
+    def register_msgtype_callback(self, path, msg_type, callback_func):
+        """
+        register msgtype with callback functions
+        """
+
 # vi:set tw=0 ts=4 sw=4 nowrap fdm=indent