[Dnsmasq-discuss] priority of local= and ipset=

[Simon Kelley]

On 07/01/2022 06:08, Justin wrote:
> thanks Simon
> 
> another related question
> 
> 1) 
> 
> if i have 6000 domains, do i write 6000 lines of local=/domain/8.8.8.8
> <http://8.8.8.8>, or do i write
> 
> local=/domain1/2/3/.../8.8.8.8 <http://8.8.8.8>
> 
> which one is faster for dnsmasq to locate and assign the nameserver? 

They're both the same.

> 
> 2) 
> 
> btw, how much time does it take for dnsmasq  ( 2.86 here) to locate one
> domain from 100,000 domains in conf-file in the form of local= or ipset=? 

How long is a piece of string? It depends on the speed of the machine.

What's more important is that the time taken grows in proportion to log
n. In older dnsmasq releases, it was linear with n, or possibly a bit
slower.

Unless you're running on very weedy hardware or with massive load,
100,000 domains should be no trouble at all.


Ahh. I just noted that you asked about ipset. The 2.86 rewrite _didn't_
include ipset, so those lookups are still O(n). Be cautious with large
numbers, and please report back if you get interesting results.

Simon.



> 
> 3) 
> 
> the search speed for local= and ipset= are the same? i mean do they use
> the same algo?
> 
> 
> 
> On Fri, Jan 7, 2022 at 07:46 Simon Kelley <simon at thekelleys.org.uk
> <mailto:simon at thekelleys.org.uk>> wrote:
> 
>     repeating a domain in --server (or --local) is sensible and dnsmasq will
>     use some or all of the servers for an individual query, depending on
>     unknowable stuff.
> 
>     You would imagine that
> 
>     ipset=/google.com/one <http://google.com/one>
>     ipset=/google.com/two <http://google.com/two>
> 
>     would be equivalent to the documented
> 
>     ipset=/google.com/one,two <http://google.com/one,two>
> 
>     but clearly it isn't. The advice is to stick to the documented way of
>     expressing those semantics, I guess.
> 
> 
>     Cheers,
>     Simon.
> 
> 
> 
>     On 04/01/2022 07:55, Justin wrote:
>     > I just did some test. looks like the 'google.com
>     <http://google.com>' will be send to both
>     > 1.1.1.1 and 8.8.8.8. but the all the resolved ip address will only be
>     > added to ipset 'one'
>     >
>     > On Tue, Jan 4, 2022 at 2:20 PM Justin <cattyhouse at gmail.com
>     <mailto:cattyhouse at gmail.com>> wrote:
>     >>
>     >> Hello
>     >> i have settings in the order like this in dnsmasq.conf
>     >>
>     >> local=/google.com/1.1.1.1 <http://google.com/1.1.1.1>
>     >> local=/google.com/8.8.8.8 <http://google.com/8.8.8.8>
>     >> ipset=/google.com/one <http://google.com/one>
>     >> ipset=/google.com/two <http://google.com/two>
>     >>
>     >> what is the behavior of dnsmasq? which nameserver will be uses to
>     >> resolve google.com <http://google.com> and which set name will
>     the resolved ip of
>     >> google.com <http://google.com> be added to?
>     >>
>     >> thanks.
>     >
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> -- 
> 
> Regards
> Justin He