[Pdns-dev] Negative Caching

Patrick Domack patrickdk at patrickdk.com
Thu Dec 20 04:30:13 CET 2012

Quoting Peter van Dijk <peter.van.dijk at netherlabs.nl>:

> Hello Patrick,
> On Nov 2, 2012, at 17:10 , Patrick Domack wrote:
>> I have been adjusting the source to increase the negative cache  
>> size, for when quering against rbl's
>> From my stats, it seems to me that the negative cache is not part  
>> of the positive cache, but totally different cache area/counters.
>> So it seems the real max-cache-size = max-cache-size * 110% (as the  
>> negative cache is hard coded at 10% of the max-cache-size currently).
>> I adjusted my source, so I could specify the negative cache size as  
>> a percentage of the max-cache-size, but as it seems to be  
>> different, I'm wondering if my patch (before I submit it in a  
>> feature request) should be changed to a negative-cache-size, that  
>> would just default to the current behavure.
> Concrete numbers are usually better than percentages of other numbers.
> In any case, please submit your patch at wiki.powerdns.com so people  
> can look at it!

I'll submit it sometime next week, I've been playing with it, and  
seeing how it works, it does seem to be seperate from stats point of  
view, and I had decided next time I look at it, to change it from  
percent to just a raw number, and just leave the default as a percent  
if undefined, so there isn't any suprises on an upgrade.

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