PypoMessageHandlers using a kombu Consumer solves MVC/Liquidsoap synchronization issues:

The real error was PypoMessageHandler wasn't consuming messages from RabbitMQ, thus schedules were only updated on PypoFetch time out.
Proably queue is in a stale state  because it didn't recover from a broken connection.
The issue is a SimpleQueue was being used, which's 'python-like' *get*  method apparently doesn't handle recovery.
Consumers are the way to go instead.

python_apps/pypo/pypo/pypomessagehandler.py

@@ -7,15 +7,32 @@ import sys
 from threading import Thread
 import time
 # For RabbitMQ
-from kombu.connection import BrokerConnection
+from kombu.connection import Connection
 from kombu.messaging import Exchange, Queue
 from kombu.simple import SimpleQueue
 from amqp.exceptions import AMQPError
 import json
 
+from kombu.mixins import ConsumerMixin
+
 logging.captureWarnings(True)
 
 
+class RabbitConsumer(ConsumerMixin):
+    def __init__(self, connection, queues, handler):
+        self.connection = connection
+        self.queues = queues
+        self.handler = handler
+
+    def get_consumers(self, Consumer, channel):
+        return [
+            Consumer(self.queues, callbacks=[self.on_message], accept=['text/plain']),
+        ]
+
+    def on_message(self, body, message):
+        self.handler.handle_message(message.payload)
+        message.ack()
+
 class PypoMessageHandler(Thread):
     def __init__(self, pq, rq, config):
         Thread.__init__(self)
@@ -26,22 +43,18 @@ class PypoMessageHandler(Thread):
 
     def init_rabbit_mq(self):
         self.logger.info("Initializing RabbitMQ stuff")
-        simple_queue = None
         try:
             schedule_exchange = Exchange("airtime-pypo", "direct", durable=True, auto_delete=True)
             schedule_queue = Queue("pypo-fetch", exchange=schedule_exchange, key="foo")
-            connection = BrokerConnection(self.config["host"],
+            with Connection(self.config["host"], \
-                                          self.config["user"],
+                            self.config["user"], \
-                                          self.config["password"],
+                            self.config["password"],\
-                                          self.config["vhost"])
+                            self.config["vhost"]) as connection:
-
+                rabbit = RabbitConsumer(connection, [schedule_queue], self)
-            channel = connection.channel()
+                rabbit.run()
-            simple_queue = SimpleQueue(channel, schedule_queue)
         except Exception, e:
             self.logger.error(e)
 
-        return simple_queue
-
     """
     Handle a message from RabbitMQ, put it into our yucky global var.
     Hopefully there is a better way to do this.
@@ -89,12 +102,7 @@ class PypoMessageHandler(Thread):
 
     def main(self):
         try:
-            with self.init_rabbit_mq() as queue:
+            self.init_rabbit_mq()
-                while True:
-                    message = queue.get(block=True)
-                    self.handle_message(message.payload)
-                    # ACK the message to take it off the queue
-                    message.ack()
         except Exception, e:
             self.logger.error('Exception: %s', e)
             self.logger.error("traceback: %s", traceback.format_exc())