nginx reverse proxy performance problems

[kevin.liu]

nginx version: nginx/1.2.0
built by gcc 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu3) 
TLS SNI support enabled
configure arguments: --add-module=/tmp/chunkin --with-http_ssl_module
--with-http_sub_module --with-http_gzip_static_module
--with-http_stub_status_module --with-pcre --prefix=/usr/local/nginx

Number of connections in the 35000 normal, the number of connections up
to 40 000, nginx the status url can sometimes open sometimes not open
,other url is such a situation.Open nginx the status url, refresh a few,
how does that matter?
nginx configuration is as follows:

user www-data;
worker_processes  8;

error_log  /var/log/nginx/error.log;
pid        /var/run/nginx.pid;
worker_cpu_affinity 00000001 00000010 00000100 00001000 00010000
00100000 01000000 10000000;
worker_rlimit_nofile 655350;
events {
	use epoll;
	worker_connections 51200;  
}

http {
    charset  utf-8;
    include       /etc/nginx/mime.types;

    access_log	/var/log/nginx/access.log ;

    sendfile       on;
    tcp_nopush     on;
    keepalive_timeout  60;
    tcp_nodelay        off;  
    gzip  on;
    gzip_disable "MSIE [1-6]\.(?!.*SV1)";
    gzip_min_length 1k;
    gzip_buffers     4 16k;
    gzip_http_version 1.0;
    gzip_comp_level 2;
    gzip_types       text/plain application/x-javascript text/css
application/xml;
    gzip_vary on;   

    client_max_body_size 128M;
    client_body_buffer_size 256k;
    client_header_buffer_size 4k;
    large_client_header_buffers 4 16k;
    proxy_connect_timeout 60;
    proxy_send_timeout 60;
    proxy_read_timeout 60;
    proxy_buffer_size 512k;
    proxy_buffers 64 256k;
    proxy_busy_buffers_size 512k;
    proxy_temp_file_write_size 512k;
    proxy_next_upstream error timeout invalid_header http_500 http_503
http_404;
    proxy_max_temp_file_size 128m;
   
    include /etc/nginx/log_format.conf;
    include /etc/nginx/proxy_upstream.conf;
    include /etc/nginx/conf.d/*.conf;
   
}

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,226673,226673#msg-226673