问HTTPS请求使用弹性负载均衡和EC2/Nginx如何解决502 Bad Gateway错误？

EN

#user  nobody;
worker_processes  1;

events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;
    access_log /etc/nginx/access.log;  
    sendfile        on;

    # Configuration containing list of application servers
    upstream app_servers {

        server 127.0.0.1:6543;
    }   

    server {
        listen       80;
        server_name  [MY-EC2-SERVER-NAME];


        # Proxy connections to the application servers
        # app_servers
        location / {

            proxy_pass         http://app_servers;
            proxy_redirect     off;
            proxy_set_header   Host $host;
            proxy_set_header   X-Real-IP $remote_addr;
            proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Host $server_name;

        }
    }
}