[Pdns-users] New documentation on PowerDNS backends, and what they are and aren't

[bert hubert]

Hi everybody,

We just posted this on our blog http://blog.powerdns.com/2015/06/23/what-is-a-powerdns-backend-and-how-do-i-make-it-send-an-nxdomain/

"PowerDNS is a dynamic nameserver, with a ton of backends. If the supplied
backends aren’t flexible enough, our architecture enable operators to write
their own, or to use one of our forwarding backends (Pipe and Remote), which
can send PowerDNS queries over a pipe, a UNIX domain socket, an HTTP
connection or even a ZMQ link.

Very often however (weekly at this point!), we get questions from users
confused about our backends:

 Why does my backend get ANY queries, when no ANY queries are sent to the
  nameserver?
 How do I generate an NXDOMAIN response from my backend?
 Why do I get SOA queries, even for domains not in my backend?
 Why does PowerDNS ignore the records my backend sent back to put in the
  packet?
 Why do I get more backend queries than DNS queries (sometimes)?
 Why do I get *way less* backend queries than DNS queries at other times?
 Why are backends launched for AXFRs?"

With your feedback, we hope to merge this blog post into our documentation
soon. Please let us know if this helps clarify what a PowerDNS backend is
supposed to do, and if we could do any better.

Thanks!

	Bert