Two masters for one zone

[Kevin Darcy]

Vladimir at isc.org, Trebicky at isc.org wrote:

> Hi,
>
> is there any way to solve this problem?:
>
> 1) I want to have to master servers for one zone, eg. "example.com"
> 2) Each of them can add records to this zone
> 3) Each of them synchronizes the other one's records
> 3) Each of them can delete its own records

You can't configure this in the nameservers if they are running BIND.
But, if you have complete control over the update process, you could
define both nameservers as "master" and have the update-client part of
the mechanism "spray" the relevant (e.g. additions but not deletions)
updates across both nameservers. As for limiting deletions to a
nameserver's "own records", again you'd need complete control of the
update process, such that every time a nameserver adds a record to the
zone, you'd need to record that "ownership" attribute somewhere (in DNS,
perhaps in a different, server-specific part of the namespace, or,
outside of DNS completely).

Any way you implement it, though, you'll have to have some way of
resolving replication conflicts. What if, for example, both nameservers
try to add a particular record before they've had a chance to replicate
with each other? Who wins? Who "owns" the record and thus has the
authority to delete it?


- Kevin