PDNS Question, or really any other auth server…

Hi DNS friends.

I have a PDNS server with mysql back end. This works great.

I also have a custom built pipe back end which also works great.

I would like a query to be first attempted with the mysql backend and then fail to the pipeback end if the record is not found in the mysql table.

This seems like a simple scenario, but perhaps I’ve been spending too much time in the sun and I don’t see an easy way to do this.

I’d even entertain switching servers. If a server could check it’s local data and if it has no record, forward the query to another server before returning the nxdomain, that would also be acceptable.

I could write my own pipe back end to handle the entire process, but this seems like overkill on something that should be fairly simple.

Is there an easy way to do this and I’m missing something? Or should I create my own pipe backend to handle this?

EDIT:

Thought I should add a simple example.

I have 2 servers configured for foo.com….

Server A:

• www.foo.com

• ftp.foo.com

Server B:

• mail.foo.com

• wiki.foo.com

I would like a query to come in to server A, and rather than server A returning NXDOMAIN for wiki.foo.com, I would like it to query server B and return the result back to the original client. These don’t have to be physically separated servers, but I could do it either way.

I know I can add NS records and handle it through delegation, but in my particular scenario, this is not going to work efficiently as we’re talking about a fairly large number of records.

Edit 2: Seems pdns probably does what I want it to do out of the box. It queries back ends in order in the config file, and does not give up on the first if it doesn’t find an exact match. This behaviour allows me to do what I need to do I think. I will provide more details and likely the source code to the sub once I have it tweaked and working.