Choosing A records based on hosts' load?

[Reindl Harald]

Am 18.01.21 um 10:04 schrieb Marek Kozlowski:
> :-)
> 
> On 1/18/21 9:59 AM, Reindl Harald wrote:
>> Am 18.01.21 um 09:49 schrieb Marek Kozlowski:
>>> I believe that such a solution (read to install) should exist. 
>>> Unfortunately I don't know the magic keywords to find it:
>>>
>>> I have a group of hosts with different IPs offering the same 
>>> services. I'm able to install some agents on them for monitoring 
>>> their network/cpu/number of users/whatever utilization. I'm wondering 
>>> if there is an option for BIND9 to obtain those load parameters on a 
>>> regular basis (let's say: every 10 minutes) and when queried for the 
>>> A record return ONLY one IP address - the one of the server with the 
>>> lowest utilization?
>>>
>>> It can be implemented on those servers but in the solution I'm asking 
>>> about the key point is that the BIND server takes the decision.
>>
>> this can't work - only a minority of clients is asking your nameserver 
>> directly, most talk to caches
>>
>> you try to solve the problem on the wrong side
>> you need a loadbalancer in front of the cluster
> 
> The problem is: I'm supervising the BIND. I'm NOT supervising the other 
> servers. Their admins requested such a solution. Personally I agree with 
> your opinion but... The question is: is there such a ready solution as I 
> described?

i doubt that someone wrote arelieable solution, it's just not the job of 
dns and even if such a solution exists it's not well tested/maintained 
by lack of consumers

reject the request with "i don't solve issues outside my responsibility 
ignoring best practices"

that starts starts with agents (network/cpu/number of users/whatever 
utilization) where you suddenly mix responsibilities

what does it mean for sour nameservers if that agents itself are 
overloaded? does it reduce the quality or even bring down nameservices?

solve problems where they exist instead compromise additional services - 
bind itself can't do it anyways, it would be whatever software which 
decides to update the dns-zone runniong outside of named