Probe dns service - anycast network

Hi, We are thinking of deploying anycast in our network for dns servers. I have the following scenario: - 10 server DNS (isc-bind) , linux and zebra for propagating ospf ip anycast. Are there someone who has developed a "solid scripts (perl/c/ecc..)" that is used to probe a dns service (udp/tcp port 53) and in case of failure (or max lookup query time problem) automatic shutdown ospf annunce or remove a server from a anycast network? Best regards Antony Findanno