hornetq stomp durable subscriber

import logging
logging.basicConfig()
#logging.getLogger().setLevel(logging.DEBUG)
import stomp

cnt=0
class RadiusListener(object):
    def on_error(self, headers, message):
        print 'received an error %s' % message

    def on_message(self, headers, message):
        global cnt
        # return these attributes from the headers in ACK frame
        ack_keys = ['message-id', 'subscription']

        if int(headers['content-length'])!=len(message):
            print "content error",headers['content-length'],len(message)
            import sys
            sys.exit(1)
        cnt+=1
        print cnt
        conn.ack(dict([(i, headers[i]) for i in ack_keys if i in headers]))


if __name__ == '__main__':
    conn = stomp.Connection(host_and_ports=[('mq.private',61612)],
                            version='1.1',
                            heartbeats=(1000, 3000),
                            user='radius_consumer',
                            passcode='pass',
                            use_ssl=True,
                            ssl_key_file = '/etc/stunnel/radius-consumer.key',
                            ssl_cert_file = '/etc/stunnel/radius-consumer.pem',
                            )
    conn.set_listener('', RadiusListener())
    conn.start()
    conn.connect(headers={'client-id':'radiusmq'})
    conn.subscribe(headers={
                            'destination':'jms.topic.radius',
                            #'destination':'/topic/radius',
                            'ack':'client',
                            'id':1,
                            'durable-subscriber-name':'radiusmq',
                            'activemq.subscriptionName':'radiusmq',
                            'selector':"Xsystem = 'wired' AND ("
                            "Xstatustype = 'STOP' OR "
                            "Xstatustype = 'INTERIM_UPDATE')",
                            }
                   )

    while True:
        import time
        print time.time()
        time.sleep(1)