nginx codeigniter 502 错误网关

nginx的配置如下：

server {
        listen       80;
        server_name  www.example.com;

        root   /home/wwwroot/example.com;
        index index.php  index.html index.htm;

        location / {
                index  index.php index.html index.htm;
        }

        location ~ \.php($|/) {
            fastcgi_pass   127.0.0.1:9000;
            fastcgi_index  index.php;
            fastcgi_split_path_info ^(.+\.php)(.*)$;
            fastcgi_param   PATH_INFO $fastcgi_path_info;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            include        fastcgi_params;
        }

        if (!-e $request_filename) {
            rewrite ^/(.*)$ /index.php/$1 last;
            break;
        }

        location ~ /\.ht {
                deny  all;
        }
}

请大家给我一些建议，谢谢~

我终于自己改正了。

server {
    listen       80;
    server_name  example.com;

    root   /home/wwwroot/example.com;
    index index.php  index.html index.htm;

    location / {
    root /home/wwwroot/example.com;
            index  index.php index.html index.htm;
        if (!-e $request_filename) {
                rewrite ^/(.*)$ /index.php/$1 last;
                break;
        }
    }
    location ~ \.php($|/) {
        fastcgi_pass  unix:/tmp/php-cgi.sock;
        fastcgi_index  index.php;
        fastcgi_split_path_info ^(.+\.php)(.*)$;
        fastcgi_param   PATH_INFO $fastcgi_path_info;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        fastcgi_params;
    }
    location ~ /\.ht {
            deny  all;
    }
}