[dns-operations] Opinions sought .... have I come to the right place?

Joe Abley jabley at hopcount.ca
Thu Nov 7 20:08:16 UTC 2013


On 2013-11-07, at 12:03, Florian Weimer <fw at deneb.enyo.de> wrote:

> * Stephan Lagerholm:
> 
>> Keep in mind that most cache system are using Least Recent Used
>> Algorithm for their cache without any removal of expired records.  
> 
> Doesn't BIND use an unbound cache by default?

I think you need to say "unbounded" to avoid knee-jerk cognitive dissonance, but hopefully at least you made some NLNet Labs people smile :-)

> | max-cache-size
> | 
> | […] A value of 0 is special, meaning that records are purged from
> | the cache only when their TTLs expire. […] The default is 0.
> 
> <ftp://ftp.isc.org/isc/bind9/9.9.4/doc/arm/Bv9ARM.ch06.html>

Someone from ISC should probably weigh in, but if that really means that on a busy cache the in-memory cache can grow beyond the extent of physical RAM and start swimming with the sharks in swap, that seems like a weird default.

But if that's what happens, it certainly helps explain the oft-shouted guidance "TUNE YOUR CACHE".


Joe
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