Add warning for ZMQ < 3 to the master

Author: basepi

salt/master.py

@@ -167,6 +167,12 @@ def __init__(self, opts):
         '''
         Create a salt master server instance
         '''
+        # Warn if ZMQ < 3
+        if int(zmq.zmq_version()[0]) < 3:
+            log.warning('You have a version of ZMQ less than ZMQ 3! There are '
+                        'known connection keep-alive issues with ZMQ < 3 '
+                        'which may result in loss of contact with minions. '
+                        'Please upgrade your ZMQ!')
         SMaster.__init__(self, opts)
 
     def _clear_old_jobs(self):