[Pdns-users] Reliable supermaster setup - howto?

Frank Louwers frank at openminds.be
Fri Oct 23 13:36:47 UTC 2009

On 23 Oct 2009 wk 43, at 15:17, Przemyslaw Wegrzyn wrote:

> Kenneth Marshall wrote:
>>> This leaves my initial  question unanswered - how does such setup  
>>> recover from lost notifications from supermaster to slave?
>>> As of PostgreSQL - my idea was to use PostgreSQL on master, and  
>>> SQLite on slave, for simplicity, but that would render your patch  
>>> useless, unfortunately. Where can I find the patch?
>> The slave will check after the cache period times out. You could
>> also run a tickle script to check that you do not have any stale
>> zones.
> I'm not sure if I understand things right - I'm talking about a  
> situation when I add a whole new zone to the master server, and I'd  
> like the slave server to add it automatically as well. The zone is  
> not yet configured on the slave, so it will not ask for that. It  
> only asks when notified by master. So the only way to make it  
> reliable, I suppose, is to repeat the notifications form master,  
> until a successful AXFR to slave occurs.

AXFR's are so 20-th century :)

No really, try other schema's if you can. Let me explain you our pdns  

We have one master database that contains all profiles. From that db,  
a script generates the actual zones every 10 minutes. These are stored  
in the PDNS Master database on our primary nameserver, using the MySQL  

NS2 and NS3 use MySQL replication to replicate that master DB.

This means that if a new zone is added and committed to the NS1 PDNS  
Master MySQL db, it is automatically available on NS2 and NS3. No need  
to configure anything on ns2/ns3, no need for AXFR, etc.

For customers that run BIND, we use the "supermaster" functionality as  

Primary BIND of the customer (CUST-NS) configures the zone, and  
notifies our NS1. Our NS1 gets the NOTIFY, sees that it doesn't know  
anything about the zone, sees that CUST-NS is a configured  
supermaster, and it will AXFR the zone from CUST-NS and commit it to  
it's own master MySQL db. Again, MySQL replication takes care of  
distributing the zone to NS2 and NS3.


Frank Louwers
Openminds bvba

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