How to monitor a name server

Hi,
You may use custom shell monitor with the following command:
nslookup <known DNS address> <name server of question>
and apply content check to the output of this command - look for the IP address of this known address. If address is present this means the name server responded ok. You may also use dig instead of nslookup.
Thank you

It would also be nice to monitor name server metrics, any hints on this would be appreaciated

Hello Alex,
We can consider this for future and provide workaround for now. 
A question: which metrics you are interested in?
Thanks

Hello Andrew, just standard performance data available via 'rndc stats' on a bind name server, ie. number of success queries, referral, nxrrset, nxdomain, failure, recursion