dwrr is Dynamic Weighted Round Robin.

icmp is load balance by ping rtt.

p2c is reference https://exceting.github.io/2020/08/13/%E8%B4%9F%E8%BD%BD%E5%9D%87%E8%A1%A1-P2C%E7%AE%97%E6%B3%95/.

wr is Weighted random.

wrr is Weighted Round Robin reference Nginx https://blog.csdn.net/zhangskd/article/details/50194069.