How to limit requests rate per visitor in engintron

[el5olfaa.com]

Hello,

In some cases we need to limit the rate of requests per ip when our website is overloaded or under heavy ddos attack.

Let's follow our instructions to do that :
1) Do the following command on server shell :

nano /etc/nginx/nginx.conf

2) Go to http section and add this after this line "http {" :

limit_req_zone $binary_remote_addr zone=mylimit:10m rate=1r/s;

This will limit 1 request per second for every visitor depending on his ip address .

3) Now we need to modify the following files by commands :

nano /etc/nginx/common_http.conf
nano /etc/nginx/common_https.conf

In each file search for the needed "location" you want to rate limit it and add the following after "location" line :

limit_req zone=mylimit;

For example :

    location /login.php {
        limit_req zone=mylimit;
        proxy_pass http://my_upstream;
    }

If you need to add a delay instead of getting an error page you need to use "burst" attribute :

limit_req zone=mylimit burst=10;

Now visitor will be delayed in case of exceeded 1 request per second for a total 10 max delayed requests if exceeded an error page will appear .

4) Reload nginx with new configuration :

service nginx reload

That's all .

Good luck