nginx经过负载多台后 TPS降低

Question

问题

nginx负载只负载到一台时 TPS能接近4W
nginx负载负载到两台时 TPS却降低到1W出头
这个为什么呢？应该怎么解决！

环境

主机
172.17.0.1 nginx centos7
172.17.0.2 tomcat centos7
172.17.0.3 tomcat centos7

nginx配置

#
user  root;
worker_processes  auto;
worker_rlimit_nofile 65536;
events {
    use epoll;
    worker_connections  65536;
    accept_mutex on;
    multi_accept on;
}
stream{
    upstream  probe {
        server 172.17.0.2:8095 weight=3;
        # server 172.17.0.3:8095 weight=3;
    }
   server {
     listen 8091;
     proxy_pass probe;
     proxy_connect_timeout 1h;
     proxy_timeout 1h;
   }

}