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;

}