+ my_instance_ids = self.get_instance_ids()
+ invalid_instances = (
+ [instance_id for instance_id in instance_ids
+ if instance_id not in my_instance_ids])
+ if invalid_instances:
+ self.log.error('Invalid instances: %s' % invalid_instances)
+ reply_state = 'NACK_MAINTENANCE'
+ else:
+ reply_state = 'ACK_MAINTENANCE'