Hi,
Few days ago, DNS forwarding was broken between two datacenters and one of the URL was broken. At that time, when I did "nslookup gemprov.clc.prdv51.com", it failed. Below is description, how it works.
The webserver/application server of this website is on servers hosted in Raleigh/Dallas. Any query goes to this URL, reached to DNS servers of Raleigh/Dallas. prdv512.com zone is not available on Raleigh/Dallas DNS servers, so there is a forwarder set, which send this query to Seattle/Phoenix (4 in numbers) DNS servers and then it will be resolved.
As a custom solution of monitoring, I want to setup something like, we should get email if the resolution doesn't work and fails. One way I can think is, setup a cronjob like below. Can it work?
Code:
dig gemprov.clc.prdv51.com | grep NOERROR 1>/dev/null || echo "DNS lookup fail from clc" | mail -s "DNS lookup of gemprov.clc.prdv51.com fails" abc_group@prdv51.com
For testing, if I make typo in domain, then only it works.
Code:
[root@lin-32serv ~]# dig gemprov123.clc.prdv51.com | grep NOERROR
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57436
[root@lin-32serv ~]# dig gemprov.clc.comtech911.com | grep NOERROR
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56694
[root@lin-32serv ~]# dig gemprov.clc.prdv51123.com | grep NOERROR
[root@lin-32serv ~]#
What would be best way to achieve it?
Advice, please
Thanks
