consumer group 和provider group设计在一起了，是有问题的

[taotao365s]

1. provider端发送消息时，需要知道consumer的group，否则消息查询不到，group设计耦合了
2. 测试用例中可以用，是因为都是DEFAULT

        List<XxlMqMessage> list = xxlMqMessageDao.pullNewMessage(XxlMqMessageStatus.NEW.name(), topic, group, consumerRank, consumerTotal, pagesize);

对应sql

SELECT <include refid="Base_Column_List" />
		FROM xxl_mq_message AS t
		WHERE 	t.topic = #{topic}
			AND t.group = #{group}
			AND t.status = #{newStatus}
			AND t.effectTime <![CDATA[ < ]]> NOW()
			<if test="consumerTotal > 1">
				AND (
					(
						t.shardingId <![CDATA[ = ]]> 0
						AND
						MOD(t.id, #{consumerTotal}) = #{consumerRank}
					)
					OR
					(
						t.shardingId <![CDATA[ > ]]> 0
						AND
						MOD(t.shardingId, #{consumerTotal}) = #{consumerRank}
					)
				)
			</if>
		ORDER BY t.id ASC
		LIMIT #{pagesize}