Migrating from a single server to two servers with DNS clustering.

[PeteS]

Server A is a standard profile server with 3 IPs (main, NS1,NS2) which handles all services.

I'm wanting to split this server off into server A and server B (also a standard profile server) and establish DNS clustering between them. The domain that the nameservers are on will move to server B. The goal is to have server B in a different data center than A, separating NS1 and NS2, and allowing the nameserver domain to be a support portal separate from client domains on server A. (Other servers, C, D, E..., could then be DNS clustered as well, but they have nothing to do with nameserver domain nor the existing nameservers.)

I've read docs on DNS clustering, but I have not set up a DNS cluster before, so I don't know if the nameserver IPs replicate across all servers, or if they are only set on the server handling that nameserver. I'm also unclear if there is a master/slave relationship, or if DNS changes in any clustered server propagate to all.

My guess was:
1- spin up server B with Cpanel Solo
2- DNS cluster A and B
3- move the nameserver domain account to B
4- remove NS2 from A and add it to B (new IP, so also update registry IP for NS2 glue record)

Is it that simple...?

 

[techAMIGO]

HI,
I think you can install cPanel DNSonly (cPanel DNSOnly® Installation | cPanel & WHM Documentation) under two seperate tiny vps ( if needed) , cPanel dns only is free ,
So you can standardise your nameservers ( ns1 and ns2 ) and cluster them, clustering is very much easier as few simple clicks by generating the whm api keys and add them

Since you need to have nameserver server to use as a support portal too then you can create a standard cpanel profile server with solo license as you said and use it as nameservers too.
( cPanel DNS only cannot be used as hosting server)

also if any zone changes happens in anyserver will sync to all servers if the cluster server is added synchronize

 

[cPanelWilliam]

I agree with @techAMIGO 's input here. It is much more common to use separate DNS Only servers to host your nameservers, then set up your Webservers to sync to the DNS Only servers. If you are going to use DNS Clustering, we recommend not using your WHM/Web servers as the authoritative nameserver for simplicity.

We have a detailed article describing this setup I'll include below:

cPanel DNS Cluster Guide

 

[PeteS]

I agree with @techAMIGO 's input here. It is much more common to use separate DNS Only servers to host your nameservers, then set up your Webservers to sync to the DNS Only servers. If you are going to use DNS Clustering, we recommend not using your WHM/Web servers as the authoritative nameserver for simplicity.

We have a detailed article describing this setup I'll include below:

cPanel DNS Cluster Guide

I have read all the docs referenced here (and more)... So you're saying that two standard profile servers, DNS clustered in a synchronize role won't work, or isn't a best practice? Assuming the latter, what is the drawback? My server A is already handling all nameserver requirements, so it seems like splitting NS1 and NS2 to two such servers would only help, and not hurt.

Is this what that would look like? --> Each server would be the authoritative nameserver for the domains hosted on it, they would each service one NS (with the glue record pointed to that server for that NS), and they would mutually snyc bi-dictionally to the most recent DNS records for all domains in the cluster.

I'm sorry if I'm missing the point here. I've read all the docs I can find and I'm still unclear.

 

[techAMIGO]

HI @PeteS
standard profile servers will work fine with DNS cluster and zones will synchronise without any issues you can proceed in this way if needed, no issues it will work perfectly as normal.. but we're trying to say is, to standardize the DNS cluster is splitting ns1 and ns2 with dns only cPanel servers. so later on you can add any number of cpanel servers to those two namerservers..

 

[PeteS]

HI @PeteS
standard profile servers will work fine with DNS cluster and zones will synchronise without any issues you can proceed in this way if needed, no issues it will work perfectly as normal.. but we're trying to say is, to standardize the DNS cluster is splitting ns1 and ns2 with dns only cPanel servers. so later on you can add any number of cpanel servers to those two namerservers..

Thank you for clarifying that it is best practice, and that my configuration also will work. I agree with your suggestion and will make it the end goal, but for now with this server I need to proceed as I outlined. A couple followup questions:

1- Going forward could I migrate the nameservers to their own DNS Only servers as you suggested?
2- Until then could I add additional standard profile servers in synchronize role to my 2 standard profile server DNS cluster)?
3- Re: Home / Server Configuration / Basic WebHost Manager® Setup (nameserver section), I get now that this would have all NS servers setup, on each server. My question is do changes made to a NS on one server propagate to cluster, or does this need to be manually updated?

Thank you again for helping me plan a short term and long term road map.

*EDIT*
I just noticed that the cPanel DNS Cluster Guide link from @cPanelWilliam is not the same Guide I thought it was! Reading that helped a lot! I will take this advise into consideration as I move forward.

*EDIT2*
One more (maybe dumb, but I just want to make sure I'm not missing something) question...
4- I understand the difference between authoritative and non-authoritative namerservers in the context of DNS lookups, but in the context of cPanel setup/configuration, are we simply talking about whether the nameserver service is enabled or not on a server? Or are there other settings/factors involved? Meaning, if DNS Only servers are used in a cluster, the nameserver service would be disabled on the website server. Or would that disable all DNS services including DNS zone management?