diff --git a/sarracenia/moth/mqtt.py b/sarracenia/moth/mqtt.py
index 552d07a3f..963ef8ae6 100755
--- a/sarracenia/moth/mqtt.py
+++ b/sarracenia/moth/mqtt.py
@@ -59,6 +59,8 @@ class MQTT(Moth):
        Message Queue Telemetry Transport support.
            talks to an MQTT broker.  Tested with mosquitto. requires MQTTv5
 
+       -  broker url schemes:  mqtt, mqtts, mqttw, mqttws
+
        Sarracenia Concept mapping from AMQP:
 
            AMQP -> MQTT topic hierarcy mapping: 
@@ -372,9 +374,15 @@ def __getSetup(self):
                             "paho library using auto_ack. may lose data every crash or restart."
                         )
     
-                    self.client.connect_async( self.o['broker'].url.hostname, port=self.__sslClientSetup(), \
+                    self.client.connect( self.o['broker'].url.hostname, port=self.__sslClientSetup(), \
                            clean_start=False, properties=props )
                     self.client.enable_logger(logger)
+                    while (self.connect_in_progress) or (self.subscribe_in_progress > 0):
+                         self.client.loop()
+                         time.sleep(0.1)
+                         if self.please_stop:
+                              break
+                         logger.info("waiting for subscription to be set up.")
                     self.client.loop_start()
                     self.connected=True
                     break
@@ -460,18 +468,21 @@ def __putSetup(self):
                 self.connect_in_progress = True
                 res = self.client.connect_async(self.o['broker'].url.hostname,
                                           port=self.__sslClientSetup(),
-                                          properties=props)
+                                         properties=props)
                 logger.info('connecting to %s, res=%s' % (self.o['broker'].url.hostname, res))
 
                 self.client.loop_start()
 
                 while self.connect_in_progress:
                      time.sleep(0.1)
+                     if self.please_stop:
+                          break
                      logger.info( f"waiting for connection to {self.o['broker']}")
                      self.client.loop()
 
-                self.connected=True
-                break
+                if not self.connect_in_progress:
+                    self.connected=True
+                    break
 
             except Exception as err:
                 logger.error("failed to {} with {}".format(
@@ -522,6 +533,8 @@ def getCleanUp(self):
                    clean_start=False, properties=props )
                 while self.connect_in_progress:
                     myclient.loop(0.1)
+                    if self.please_stop:
+                       break
                 myclient.disconnect()
                 logger.info('instance deletion for %02d done' % i)
 
@@ -696,8 +709,9 @@ def putNewMessage(self,
         props.ContentType = PostFormat.content_type( postFormat )
 
         try:
-            raw_body, headers, content_type = PostFormat.exportAny( body, postFormat, [exchange]+self.o['topicPrefix'], self.o )
+            raw_body, headers, content_type = PostFormat.exportAny( body, postFormat, self.o['topicPrefix'], self.o )
             # FIXME: might
+            logger.critical( f" headers:{headers} format: {postFormat}, pfx: {self.o['topicPrefix']} " )
             topic = '/'.join(headers['topic']) 
 
             # url-quote wildcard characters in topics.
diff --git a/sarracenia/postformat/__init__.py b/sarracenia/postformat/__init__.py
index 7ad37e3c7..13c02d2b4 100644
--- a/sarracenia/postformat/__init__.py
+++ b/sarracenia/postformat/__init__.py
@@ -75,6 +75,38 @@ def exportAny(msg, post_format='v03', topicPrefix=[ 'v03' ], options={ 'post_for
 
         return None, None, None
 
+    def topicDerive(msg, options ) -> list:
+        """
+           Sarracenia standard topic derivation.
+
+           https://metpx.github.io/sarracenia/Explanation/Concepts.html#amqp-v09-rabbitmq-settings
+        """
+
+        if options['broker'].url.scheme.startswith('mqtt'):
+            if ( 'exchange' in options ) and ( 'topicPrefix' in options ):
+                if 'exchangeSplit' in options and options['exchangeSplit'] > 1:
+                    idx = sum( bytearray(msg['identity']['value'], 'ascii')) % len(options['exchange'])
+                    exchange = options['exchange'][idx]
+                else:
+                    exchange = options['exchange'][0]
+            topic_prefix = [exchange] + options['topicPrefix']
+            topic_separator='/'
+        else:
+            topic_prefix = options['topicPrefix']
+            topic_separator='.'
+
+        if 'topic' in options:
+            topic = options['topic'].split(topic_separator)
+        else:
+            if 'relPath' in msg: 
+                topic = topic_prefix + msg['relPath'].split('/')[0:-1]
+            else:
+                topic = topic_prefix
+
+        return topic
+
+   
+
 # test for v04 first, because v03 may claim all other JSON.
 import sarracenia.postformat.wis
 import sarracenia.postformat.v03
diff --git a/sarracenia/postformat/v02.py b/sarracenia/postformat/v02.py
index 49a7fbd0f..996df758b 100644
--- a/sarracenia/postformat/v02.py
+++ b/sarracenia/postformat/v02.py
@@ -139,7 +139,7 @@ def exportMine(body, options) -> (str, dict, str):
            given a v03 (internal) message, produce an encoded version.
        """
         v2m = v2wrapper.Message(body)
-
+                                
         # v2wrapp
         for h in [
                     'pubTime', 'baseUrl', 'fileOp', 'relPath', 'size', 
@@ -148,8 +148,6 @@ def exportMine(body, options) -> (str, dict, str):
             if h in v2m.headers:
                     del v2m.headers[h]
 
-        if ( 'broker' in options ) and ( 'exchange' in options ) and \
-            options['broker'].url.scheme.startswith('mqtt'):
-            v2m.headers['topic'] = options['exchange'] +  v2m.headers['topic']
+        v2m.headers['topic'] = PostFormat.topicDerive( body, options )
 
         return v2m.notice, v2m.headers, V02.content_type()
diff --git a/sarracenia/postformat/v03.py b/sarracenia/postformat/v03.py
index 0bea6ee09..80dcbd63c 100644
--- a/sarracenia/postformat/v03.py
+++ b/sarracenia/postformat/v03.py
@@ -86,23 +86,6 @@ def exportMine(body,options) -> (str, dict, str):
        """
         raw_body = json.dumps(body)
 
-        topic_separator='.'
-
-        if options['broker'].url.scheme.startswith('mqtt'):
-            if ( 'exchange' in options ) and ( 'topicPrefix' in options ):
-                topic_prefix = options['exchange'] + options['topicPrefix'] 
-            topic_separator='/'
-        else:
-            topic_prefix = options['topicPrefix']
-
-        if 'topic' in options:
-            topic = options['topic'].split(topic_separator)
-        else:
-            if 'relPath' in body:
-                topic = topic_prefix + body['relPath'].split('/')[0:-1]  
-            else:
-                topic = topic_prefix
-
-        headers = { 'topic': topic }
+        headers = { 'topic': PostFormat.topicDerive(body,options) }
 
         return raw_body, headers, V03.content_type()