pymqi commands are all blocked

Question

I have the following environment:

• Redhat
• Python 2.7

I have a module which reads messages from an IBM MQ and then process them. The scenarios is as follows:

1. Start the application
2. Simulate connection is lost with the VM where the IBM MQ resides by issuing ifdown eth0 command
3. As expected the connection is lost

Expected behavior:

• An pymqi.MQMIError being raised

Observed behavior:

• All the pymqi calls just get blocked. The running thread does nothing unless the connection is enabled again with ifup.

This is part of the code:

def connect_and_subscribe(self):
    """Connect to IBM MQ and subscribe"""
    self.qmgr         = pymqi.connect(self.qmgr_name, self.qmgr_channel, self.qmgr_connect)
    self.queue        = pymqi.Queue(self.qmgr, self.queue_name)
    self.queue_i      = pymqi.Queue(self.qmgr, self.queue_name)
    self.queue_i_type = self.queue_i.inquire(pymqi.CMQC.MQIA_Q_TYPE)
    self.connected    = True
    logging.info('CONNECTED TO MQ USING PYMQI VERSION <%s>' % (pymqi.__version__))
    return

#--------------------------------------------------------------------

    m = None
    # Message Options
    gmo = pymqi.GMO()
    gmo.Options = pymqi.CMQC.MQGMO_WAIT | pymqi.CMQC.MQGMO_FAIL_IF_QUIESCING | pymqi.CMQC.MQPMO_SYNCPOINT
    gmo.WaitInterval = self.max_cycle_wait_secs * 1000

    while True:
        try:
            m = None
            md = pymqi.MD()
            m = self.queue.get(None, md, gmo)
            self.queue.commit()

        except pymqi.MQMIError as e:
            if e.reason == pymqi.CMQC.MQRC_NO_MSG_AVAILABLE:

          .....

Any ideas?