Nginx平滑的基于权重轮询算法描述为: Algorithm is as follows: on each peer selection we increase current_weight of each eligible peer by its weight, select peer with greatest current_weight and reduce its current_weight by total number of weight points distributed among peers. 算法执行2步,选择出1个当前节点: 每个节点,用它们的当前值加上它们自己的权