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

Florian Weimer fw at deneb.enyo.de
Thu Nov 7 20:30:32 UTC 2013

* Joe Abley:

>> | 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.

I think we've already discussed that somewhere.

There are two other halfway plausible choices: a ridiculously low
default value (Unbound, PostgreSQL) or something scaled arbitrarily
with available memory (Hotspot reserves a quarter of physical RAM).

None of these choises is really ideal.  Many users will never change
the defaults until they hit a problem, so I can understand to some
degree why you would prefer defaults which increase performance under
benign circumstances, like BIND and Hotspot.

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