使用 nginx 代理的 websocket 经常会出现消息延迟的现象，请问可能是什么原因？

个人的 nginx 配置如下：

upstream websocket { server 127.0.0.1:10300; server 127.0.0.1:10301; server 127.0.0.1:10302; } server { listen 80; client_max_body_size 4G; access_log /home/work/logs/nginx_access.log; error_log /home/work/logs/nginx_error.log; # 域名 server_name www.example.com; add_header X-UA-Compatible "IE=edge,chrome=1"; # IE 用最新内核渲染页面 location / { proxy_pass http://websocket; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "Upgrade"; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_set_header X-NginX-Proxy true; proxy_redirect default; add_header "Access-Control-Allow-Origin" "*"; add_header "Access-Control-Allow-Credentials" "true"; add_header "Access-Control-Allow-Headers" "X-Requested-With"; } }