[Pdns-users] Duplicate RRs in records table

[Klaus Darilion]

On 03.07.2014 17:41, ktm at rice.edu wrote:
> On Thu, Jul 03, 2014 at 05:30:52PM +0200, Klaus Darilion wrote:
>>> Hi Klaus,
>>>
>>> We use gpgsql as well. We only have problems on the initial transfer of
>>> the zone because there are no existing records in the domain. Then if
>>> multiple AXFRs are started, records can be duplicated. Once the zone has
>>> been populated, the delta logic prevents anymore duplication of records.
>>
>> I think your delta-logic is not needed to prevent duplications. (but
>> there may be other reasons why you need the delta logic)
>>
>> regards
>> Klaus
>>
> Hi Klaus,
> 
> We calculate the delta because we do not perform the initial zone delete
> followed by a complete re-population. We have the zone tranfer load into
> a temporary table and then join it with the existing records table to
> calculate what to delete/insert to make them the same.

Interesting idea. Do you achieve this solely with SQL queries? I would
like to see them.

> This really reduces
> the WAL generated as well as the table re-writes caused by the full delete/
> re-populate cycles for the typical case of a 1 or 2 record delta.

I am just curios: do you have real problems with the standard behavior
(WAL files fill up your disk, the zones are so huge that you have
problems while inserting the new records)? Or it just cosmetic?

In our setup we use the default behavior. We have ~1 WAL file per minute
(16MB) which we just rsync to a backup server.

regards
Klaus