Всем привет.
Собственно в чем проблема. При проверке сайта утилитой
ab -n 1000 -c 100 http://www.mysite.com/ - сайт мгновенно падает и даже если выставить параметр -n 100 - ситуация та же.
Нашел статью по решению этой проблемы: http://habrahabr.ru/blogs/nginx/124684/
Все делаю как описано в статье. Вот мой конфиг /etc/ngnix/sites-available/000-mysite.com

server {
listen 192.168.1.1:80;
server_name mysite.com www.mysite.com;

location ~* ^/(webstat/|awstats|webmail/|myadmin/|manimg/|cgi-bin/) {
proxy_pass http://192.168.1.1:8080;
proxy_redirect http://mysite.com:8080/ /;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Real-IP $remote_addr;
}
location / {
proxy_pass http://192.168.1.1:8080;
proxy_redirect http://mysite.com:8080/ /;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Real-IP $remote_addr;

proxy_cache cache;
proxy_cache_valid 10m;
proxy_cache_valid 404 1m;


}
location ~* ^.+\.(jpg|jpeg|gif|png|svg|js|css|mp3|ogg|mpe?g|avi|zip|gz|bz2?|rar)$ {
root /srv/d_mysite/www/mysite.com/htdocs;
access_log /srv/d_mysite/www/mysite.com/logs/nginx-mysite.com-access.log;
error_page 404 = @fallback;
}
location @fallback {
proxy_pass http://192.168.1.1:8080;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Real-IP $remote_addr;
}
}

proxy_cache_path /var/lib/nginx/cache levels=1:2 keys_zone=cache:30m max_size=1G;
proxy_temp_path /var/lib/nginx/proxy 1 2;
proxy_ignore_headers Expires Cache-Control;
proxy_cache_use_stale error timeout invalid_header http_502;
proxy_cache_bypass $cookie_session;
proxy_no_cache $cookie_session;

После рестарта ngnix я получаю сообщение об ошибке:

Restarting nginx: nginx: [emerg] the size 31457280 of shared memory zone "cache" conflicts with already declared size 0 in /etc/nginx/sites-enabled/000-mysite.com:36
nginx: configuration file /etc/nginx/nginx.conf test failed

Вот сам файл /etc/nginx/nginx.conf

user www-data;
worker_processes 4;
pid /var/run/nginx.pid;

events {
worker_connections 768;
# multi_accept on;
}

http {

##
# Basic Settings
##

sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
# server_tokens off;

# server_names_hash_bucket_size 64;
# server_name_in_redirect off;

include /etc/nginx/mime.types;
default_type application/octet-stream;

##
# Logging Settings
##

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

##
# Gzip Settings
##

gzip on;
gzip_disable "msie6";

# gzip_vary on;
# gzip_proxied any;
# gzip_comp_level 6;
# gzip_buffers 16 8k;
# gzip_http_version 1.1;
# gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

##
# Virtual Host Configs
##

include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
}


#mail {
# # See sample authentication script at:
# # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
#
# # auth_http localhost/auth.php;
# # pop3_capabilities "TOP" "USER";
# # imap_capabilities "IMAP4rev1" "UIDPLUS";
#
# server {
# listen localhost:110;
# protocol pop3;
# proxy on;
# }
#
# server {
# listen localhost:143;
# protocol imap;
# proxy on;
# }
#}

Версия ngnix

nginx -V
nginx: nginx version: nginx/1.0.5
nginx: TLS SNI support enabled
nginx: configure arguments: --prefix=/etc/nginx --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-log-path=/var/log/nginx/access.log --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --lock-path=/var/lock/nginx.lock --pid-path=/var/run/nginx.pid --with-debug --with-http_addition_module --with-http_dav_module --with-http_geoip_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_realip_module --with-http_stub_status_module --with-http_ssl_module --with-http_sub_module --with-http_xslt_module --with-ipv6 --with-sha1=/usr/include/openssl --with-md5=/usr/include/openssl --with-mail --with-mail_ssl_module --add-module=/build/buildd/nginx-1.0.5/debian/modules/nginx-echo --add-module=/build/buildd/nginx-1.0.5/debian/modules/nginx-upstream-fair

apache2 -v
Server version: Apache/2.2.14 (Ubuntu)

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.04.3 LTS
Release: 10.04
Codename: lucid

Помогите решить этот вопрос. Или возможно есть другой способ защиты от такой "атаки"?
Спасибо.