nginx 代理 web socket 报错“WebSocket is already in CLO

nginx 代理 web socket 报错“WebSocket is already in CLOSING or CLOSED state.”

在生产环境中需要使用 nginx 代理 websocket ，按照正常配置之后发现浏览器一直提示 “WebSocket is already in CLOSING or CLOSED state.”

这是因为 nginx 在代理需要添加如下两个参数

           proxy_set_header Upgrade $http_upgrade;
           proxy_set_header Connection "upgrade";

加上如下参数正常