upstream timed out (60: Operation timed out)

[darksmoke]

upstream site {
    server xx.xx.xx.185:33084 max_fails=20 fail_timeout=1;
    server xx.xx.xx.96:33084 max_fails=20 fail_timeout=1;
     server xx.xx.xx.94:7070 max_fails=20 fail_timeout=1;
     serverxx.xx.xx.167:7070 max_fails=20 fail_timeout=1;

}


server {
    server_name site.loc;
    listen 80;

    access_log  /opt/nginx/logs/now/site.access.log;
    error_log   /opt/nginx/logs/site.error.log error;

    location / {
        proxy_pass http://site;

        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-Request-Id $request_id;

        proxy_read_timeout 3s;
        proxy_send_timeout 3s;
        proxy_next_upstream error http_502 http_500 http_503 http_504
timeout;
    }
}

Posted at Nginx Forum: https://forum.nginx.org/read.php?21,282422,282426#msg-282426