wget http://download.github.com/replay-ngx_http_consistent_hash-77b6940.tar.gz
tar zxvf replay-ngx_http_consistent_hash-77b6940.tar.gz
cd nginx-0.7.65
./configure --prefix=/home/nginx   --with-pcre=/tmp/pcre-8.01 --with-http_stub_status_module --with-http_ssl_module --without-http_rewrite_module --add-module=/tmp/nginx_upstream_hash-0.3 --add-module=/tmp/replay-ngx_http_consistent_hash-77b6940
make && make install

upstream images6.static.com {
    server 11.11.11.12:80;
    server 11.11.11.13:80;
    consistent_hash $request_uri;
}

upstream backup {
    server 11.11.11.14:80;
}

error_page 404 500 502 503 504 =200 @fetch;
location @fetch {
    proxy_pass        http://backup;
    proxy_set_header   Host             $host;
    proxy_set_header   X-Real-IP        $remote_addr;
    proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
}