Get metrics for each MapReduce task
        Return a dictionary of {task_id: 'tracking_url'} for each MapReduce task

def _mapreduce_task_metrics(self, running_jobs, auth, ssl_verify, addl_tags):
        """
        Get metrics for each MapReduce task
        Return a dictionary of {task_id: 'tracking_url'} for each MapReduce task
        """
        for job_stats in itervalues(running_jobs):

            metrics_json = self._rest_request_to_json(
                job_stats['tracking_url'], auth, ssl_verify, 'tasks', self.MAPREDUCE_SERVICE_CHECK, tags=addl_tags
            )

            if metrics_json.get('tasks'):
                if metrics_json['tasks'].get('task'):

                    for task in metrics_json['tasks']['task']:
                        task_type = task.get('type')

                        if task_type:
                            tags = [
                                'app_name:' + job_stats['app_name'],
                                'user_name:' + job_stats['user_name'],
                                'job_name:' + job_stats['job_name'],
                                'task_type:' + str(task_type).lower(),
                            ]

                            tags.extend(addl_tags)

                            if task_type == 'MAP':
                                self._set_metrics_from_json(task, self.MAPREDUCE_MAP_TASK_METRICS, tags)

                            elif task_type == 'REDUCE':
                                self._set_metrics_from_json(task, self.MAPREDUCE_REDUCE_TASK_METRICS, tags)