[Pdns-users] Recursor: Black list

[Ciro Iriarte]

2014-10-27 14:27 GMT-03:00 Aki Tuomi <cmouse at youzen.ext.b2.fi>:
> On Mon, Oct 27, 2014 at 01:56:17PM -0300, Ciro Iriarte wrote:
>> 2014-10-27 3:46 GMT-03:00 Aki Tuomi <cmouse at youzen.ext.b2.fi>:
>> >
>> > In a way i'd chosen sqlite3 instead as it is pretty much on par with cdb.
>> > But, to make it work properly, i'd just add "*.domain.com", and when you lookup,
>> > you could reduce it like this with get()
>> >
>> > www.my.long.name.com => NOT FOUND
>> > *.my.long.name.com => NOT FOUND
>> > *.long.name.com => NOT FOUND
>> > *.name.com => FOUND
>> >
>> > (
>> > of course you could continue with
>> > *.com
>> > *
>> > )
>> >
>> > Aki
>>
>> Hi Aki!, I couldn't find a (finished) benchmark that compares directly
>> sqlite3 vs cdb, but the unfinished tests imply that cdb is faster.
>> Given it's SQL I assume we can just use a SELECT with LIKE clause to
>> match an "ending" on the DB with the requested fqdn, would it be
>> faster than doing multiple cdb queries (one for each part of the
>> requested fqdn)?
>>
>> Regards,
>>
>> --
>> Ciro Iriarte
>> http://iriarte.it
>> --
>>
>
> The difference, to my eyes, is the diference between
>
>   SELECT name FROM table WHERE name LIKE '%suffix';
>
> and
>
>   SELECT name FROM table WHERE name = 'www.my.long.name.com';
>   SELECT name FROM table WHERE name = '*.my.long.name.com';
>   SELECT name FROM table WHERE name = '*.long.name.com';
>   SELECT name FROM table WHERE name = '*.name.com';
>   SELECT name FROM table WHERE name = '*.com';
>
> (assuming you'll want to filter out, say, *.xxx)
>
> Obviously using suffix would require you to know what you are
> doing, since you'd have to know what suffix to look for, otherwise
> you'll end up with very unpredicable behaviour.
>
> Consider, you have www.name.com in your blacklist, you'll look for
> %.name.com. It'll always return match. So it's safer to go with
> repeated lookups for *.parent.
>
> Performance-wise you should consider that your most likely usage
> patterns are,
>
> not blacklisted:
>   SELECT name FROM table WHERE name = 'www.name.com';
>   SELECT name FROM table WHERE name = '*.name.com';
>   SELECT name FROM table WHERE name = '*.com';
>
> blacklisted:
>   SELECT name FROM table WHERE name = 'www.name.com';
>
> or:
>   SELECT name FROM table WHERE name = 'www.name.com';
>   SELECT name FROM table WHERE name = '*.name.com';
>
>
> to give proper answer whether SQLite3 or CDB is better, you'd have to
> run benchmark tests against these use cases as they cover most of your
> situations.
>
> Also, you might want to consider early-break on any query ending with
> in-addr.arpa and i6.arpa, unless you are required to filter these too,
> because you can get pretty long iterations especially with IPv6 reverses.
>
> All in all, i'd say go with cdb, since you already have the code there
> and it's not a big mod to make. Just keep this is mind.
>
> ---
> Aki

Thanks a lot for the suggestions, got a new version at
http://iriarte.it/?p=348, it apparently works fine. Anybody would care
to benchmark it? :)

Regards,

-- 
Ciro Iriarte
http://iriarte.it
--