Some domains don't resolve.
Sten Carlsen
ccc2716 at vip.cybercity.dk
Sat Jun 7 23:33:59 UTC 2008
I am sorry if this came out that way. I actually tried to agree with you
but based on my own experience.
I believe the original question assumed that forwarding was beneficial,
I will just say that my experience is different.
Barry Margolin wrote:
> In article <g2dhd2$1mb8$1 at sf1.isc.org>,
> Sten Carlsen <ccc2716 at vip.cybercity.dk> wrote:
>
>
>> The question as I read it, is if a very small amount of users will
>> benefit most from using the cached lookups of a large number of users
>> (the whole ISP population) or from having their own independent resolver.
>>
>> I have that situation here, I first used forward but later switched to
>> just resolving. My feeling (I have no statistics) is clearly in favour
>> of NOT forwarding. I don't see any speed penalty in real life but got
>> rid of some mysterious issues that happened while forwarding and the
>> speed seems to be higher.
>>
>
> I'm not saying that I recommend forwarding. I don't, because it adds an
> extra layer of dependency, and the benefit is probably not worth it.
>
> I was just refuting the guy who said that the theory that you get better
> cache hits is a myth.
>
>
>> Barry Margolin wrote:
>>
>>> In article <g2aeee$1bb9$1 at sf1.isc.org>, Kevin Darcy <kcd at chrysler.com>
>>> wrote:
>>>
>>>
>>>
>>>> Barry Margolin wrote:
>>>>
>>>>
>>>>> But if your ISP has 100,000 users of the same caching server, it will be
>>>>> cached if any of 1,000 users have accessed it recently. For any one of
>>>>> them, there's only a 0.1% chance that their lookup will be the one that
>>>>> has to wait for fetching from the source.
>>>>>
>>>>>
>>>>>
>>>> And if you have 100,000 users using the same caching server, it's likely
>>>> to experience big spikes of activity (e.g. several thousands of queries,
>>>> within the course of less than a second), during which time some users
>>>> will experience some extra delay in getting their queries resolved.
>>>>
>>>>
>>> Certainly if the nameserver is not engineered to handle the load it's a
>>> bad idea to use it as a forwarder. That's a completely different issue
>>> than whether it's useful to share caches via a forwarding hierarchy.
>>>
>>>
>>>
>
>
--
Best regards
Sten Carlsen
No improvements come from shouting:
"MALE BOVINE MANURE!!!"
More information about the bind-users
mailing list