Limit robots

[António P. P. Almeida]

On 13 Jan 2012 13h36 WET, nginx-forum at nginx.us wrote:

> Hello,
>
> Is there a chance to limit robots to 1 request per second?
> The down below does not work:  [emerg] "limit_req" directive is not
> allowed here

Yes. Try:

At the *http* level:

limit_req_zone $http_user_agent zone=useragenttrack:1m rate=1r/s; 

map $http_user_agent $is_bot {
    default 0;
    ~[a-z]bot[^a-z] 1;
}

At the server level:

location / {
    error_page 418 @bots;

    if ($is_bot) {
      return 418;  
    }
    ...
}

location @bots {
   limit_req zone=useragenttrack burst=100 nodelay;  
   ...
}

Cf: http://wiki.nginx.org/HttpLimitReqModule

--- appa