The nginx make proxy server...

Some time was ok,some time :
[error] 18528#0: *50881 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 222.178.73.129, server: oa.owenschool.com, request: "GET / HTTP/1.1", upstream: "http://10.2.4.33:80/", host: "oa.owens.com.cn"

Why? But some time is ok, some time is error....

The proxy config file:

server {
listen 80;
server_name oa.owens.com.cn;
location / {
root html;
index index.html index.htm;
proxy_pass http://10.2.4.11;
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 Accept-Encoding "";
proxy_connect_timeout 60;
proxy_send_timeout 60;
proxy_read_timeout 60;
proxy_buffer_size 512k;
proxy_buffers 8 512k;
proxy_busy_buffers_size 512k;
}


location = /50x.html {
root html;
}


}