[Pdns-dev] A & CNAME

David Saez eslist at ols.es
Wed Jan 4 12:57:15 CET 2012


ah, ok, i see the gmysql query definition for any, maybe the skip-cname 
documentation should
be updated in http://doc.powerdns.com/dns-to-query.html where it says 
"In reality, each query
for a question tuple first involves checking for a CNAME"
> Hi David,
> On Jan 4, 2012, at 12:31 , David Saez wrote:
>> Hi
>> so, for every request, powerdns does not a CNAME databse lookup and then a A database
>> lookup if it did notr find the CNAME record, right ?
>> if this is true and your zones contain more A records than CNAME records , then most of
>> the CNAME databse lookups are useless (and take valuable resources), for those cases
>> it's possible to save those lookups by:
>> a) first do the A lookup and the then CNAME lookup
>> or
>> b) allow hostnames in the A record and when found return a CNAME
> For every request, PowerDNS does an ANY database lookup. If there's a CNAME in there, it follows the chain; if there's an A in there, it's done. There are only extra queries *if* the first ANY lookup yields a CNAME. So, PowerDNS already does something better than suggestion (a).
> Kind regards,
> Peter van Dijk
> Netherlabs
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