recv() failed (104: Connection reset by peer) while reading response header from upstream

nginx http模块添加以下参数配置：

client_header_buffer_size 64k;
large_client_header_buffers 4 64k;
client_body_buffer_size 20m;
fastcgi_buffer_size 128k;
fastcgi_buffers 4 128k;
fastcgi_busy_buffers_size 256k;
gzip_buffers 16 8k;
proxy_buffer_size 64k;
proxy_buffers 4 128k;
proxy_busy_buffers_size 256k;

keepalive_timeout 240;
fastcgi_connect_timeout 600;
fastcgi_send_timeout 600;
fastcgi_read_timeout 600;

proxy_connect_timeout 600s;
proxy_send_timeout 1200;
proxy_read_timeout 1200;