performance hit in using too many if's

[Anoop Alias]

I understand that the map may look cleaner on the config as each vhost
don't need the if matchings ..but the variable evaluation and
therefore the pattern matching for all possible values  is still
happening when the mapped variable in encountered? and therefore there
is still a huge performance penalty ?

I am mainly asking this..as the above type of security configs are
mostly not seen on nginx official blogs /documentation etc .
Just wanted to know if people who know the internals have purposefully
omitted these setting even though they are serving the purpose of
security.



On Sat, Sep 24, 2016 at 2:45 PM,  <lists at lazygranch.com> wrote:
> ‎I suspect the map module can do that more efficiently. There is an example of how to use the map module in this post:
>
> http://ask.xmodulo.com/block-specific-user-agents-nginx-web-server.html
>
> The code is certainly cleaner using map. I use three maps, specifically for  bad user agent, bad request, and bad referrer.
>
>
>
>   Original Message
> From: Anoop Alias
> Sent: Saturday, September 24, 2016 1:58 AM
> To: Nginx
> Reply To: nginx at nginx.org
> Subject: performance hit in using too many if's
>
> Hi,
>
> I was following some suggestions on blocking user agents,sql
> injections etc as in the following URL
>
> https://www.howtoforge.com/nginx-how-to-block-exploits-sql-injections-file-injections-spam-user-agents-etc
>
> Just wanted to know what is the performance hit when using so many of
> these if's ( in light of the if-is-evil policy ). Especially if the
> server is having a lot of virtual hosts and the rules are matched for
> each of them.
>
> Is it like:
>
> If the server is capable (beefy) it should be able to handle these URL ?
>
> or
>
> There is a huge performance penalty .Significantly more than
> apache+mod_security as an example
>
> or
>
> The is a performance penalty but not as much as other security tools
> or WAF's like naxsi or mod_security
>
>
> Thanks in advance,
>
> --
> Anoop P Alias
>
> _______________________________________________
> nginx mailing list
> nginx at nginx.org
> http://mailman.nginx.org/mailman/listinfo/nginx
>
> _______________________________________________
> nginx mailing list
> nginx at nginx.org
> http://mailman.nginx.org/mailman/listinfo/nginx



-- 
Anoop P Alias