Health Check feature in BIND ?

[Mike Hoskins (michoski)]

-----Original Message-----

From: "<Lawrence K. Chen>", "P.Eng." <lkchen at ksu.edu>
Date: Monday, June 17, 2013 2:55 PM
To: Gaurav Kansal <gaurav.kansal at nic.in>
Cc: "bind-users at lists.isc.org" <bind-users at lists.isc.org>
Subject: Re: Health Check feature in BIND ?

>----- Original Message -----
>> Dear All,
>> 
>> I was just thinking whether it is possible to have a some type of
>> health checking of servers through BIND DNS Server and DNS Server
>> should replied to clients based on that only.
>> 
>> 
>> 
>> i.e., Suppose I have two entries of www record for domain xyz.in
>> having ip address 10.1.1.10 and 10.2.2.10.
>> 
>> Now I want that my DNS Server should check whether the server is up
>> or not before replying to clients.
>> 
>> If one is down, then DNS server should reply the IP address of the
>> second one.
>> 
>> 
>> 
>> Although this is not a DNS Job and we should use Load-Balancer for
>> this.
>> 
>> But I just wanna to check whether this feature is available in Bind
>> or in any Open-Source Program which in turn can be combined with
>> BIND to achieve the desired result.
>> 
>
>Well, doesn't DNS kind of already do this...if the first DNS server isn'
>up, then the user's resolver will timeout and try the next resolver....

For DNS/MX yes, but I didn't read that as a limitation of the original
request (e.g. how would you do the same auto-redirect with web or other
server types -- round robin alone can be particularly problematic).

You could certainly handle the more generic case with commercial
appliances, or a bit of tinkering on a budget.