DNS Cluster with cPanel/WHM

[sajithgsm]

Hi,
I'm trying to clustering the all dns zone with a master server and child server.

one.abc.com is master server
two.abc.com is other server.

WHM > DNS Cluster in the Master Server, I added other server and it is appearing in the bottom page now.

this screenshot is the Master Server’s DNS Cluster page and it showing the 2nd server’s record and I selected Synchronize Changes there.

----


This 2nd Screenshot is in the two.abc.com (other server) and in this screenshot showing the master server record in DNS Cluster Page and I selected Standalone.

Is this the correct method? or there should be change the DNS role as opposite?

 

[sajithgsm]

and I want to create a multiple Master DNS servers in several locations. Is it also possible?

 

[DennisMidjord]

Doing it like that is not the recommended way. You should not configure your different name servers to connect to each other.

Once you've setup all of your name servers, go to each of your cPanel/WHM servers (not the DNSOnly servers) and add all of your name servers.
If you check the DNS Path Diagram in the DNS Cluster interface, it should look like this:

webhosting.abc.com
↳ one.abc.com
↳ two.abc.com

See this for more information: Guide to DNS Cluster Configurations | cPanel & WHM Documentation

 

[sajithgsm]

Hi @DennisMidjord ,

Actually, I was mentioning one.abc.com and two.abc.com as hostnames of the servers.

 

[DennisMidjord]

Ah, so you're not using any DNSOnly servers?

 

[sajithgsm]

Thank you so much @DennisMidjord

Today im going to create a dns only server.

may I know is there any possibility to maintain 2 or 3 DNS only server to maintain the 100% uptime for main cluster dns server?

 

[DennisMidjord]

Yes. We have 3 DNSOnly servers in our cluster.

 

[sajithgsm]

Can you please give me how to handle it? Think we purchase 2 VPS from different locations and set up the DNS Only WHM/cPanel server.
what will be the further configurations?

 

[sajithgsm]

@DennisMidjord

I added DNS Only Server and here it is the method I added it.

MainServer (Synchronize Changes) >> Slave1 (Standalone) | Slave2 (Standalone)

Can you please tell me which method I add the 2nd DNS Only Server?

 

[cPRex]

Thanks for the details, @DennisMidjord

@sajithgsm - all the DNSOnly machines would get added to the cluster in the same way. Most people setup their cluster like @DennisMidjord mentioned, using the image here:

Guide to DNS Cluster Configurations | cPanel & WHM Documentation

A DNS cluster is a group of nameservers that share records with each other.

docs.cpanel.net

so the webserver(s) can be served by multiple DNSOnly machines.

Does that help clear things up?

 

[sajithgsm]

Dear @DennisMidjord
Dear @cPRex

Is this the method should I configure 3 DNS Only Servers with other servers?

 

[DennisMidjord]

Yes, that is the recommended way to configure the DNS cluster.

 

[citizen8601]

I'm puzzled about the roles. I would have expected the roles to be reversed, based on the DNS cluster documentation which says:

Servers with a Standalone DNS role receive changes from zones with newer serials (modified timestamps) but will not send signals to modify other servers. Most administrators use this setting on their DNS profile servers.

Servers with a Synchronize DNS role synchronize records between the local server and the remote server, prioritizing the server with the most recent changes. If a Synchronize server tries to push changes to a DNS zone that has been updated more recently than the Synchronize server, it will also pull the changes from the updated zone. Using the Synchronize setting on servers with DNS profiles can cause overwrite conflicts. Most administrators use this setting on their standard profile servers.

(emphasis mine)

Can someone help me clear up the apparent disagreement between documentation and the recommendation in this thread?

 

[sajithgsm]

I set it up as the above method. DNS-only servers will be always synchronized and all other servers will be standalone. I set two DNS Only Servers from two locations (Two DCs) and everything works great now.

 

[citizen8601]

@sajithgsm Thank you for following up, and thank you for the excellent image! It is helpful to hear that this is working as intended for you.

I am looking to understand cluster configuration more deeply, so I am still wondering what I am missing in comparing your setup with the documentation. It appears that "roles" actually represent relationships between the servers.

To use an example from your setup, when you go to cPanel Server 1 and there configure the role for DNS Server 1 as "synchronize", cPanel Server 1 says something to DNS Server 1, but I'm not really sure what it's saying. It could be, "I will push updates to you, but not without first asking you for recent changes and merging them with any changes that I didn't know about yet."

And when you go to DNS Server 1 and there configure the role for cPanel Server 1 as "standalone", DNS Server 1 says to cPanel Server 1, "I will receive updates from you but if I get a updates from another source, I will not push them out to you."

I suppose in that case, cPanel Server 1 will only receive updates from DNS Server 1 if it asks for them. This seems to make sense to get your cluster working, although I am not yet seeing how the "standalone" role is necessary. If all roles were "synchronize", would we not still have the most recent changes reaching the DNS servers with the added benefit of having the web servers kept up-to-date? And again, what of the documentation, which seems to suggest the roles be the reverse of @sajithgsm's setup?

 

[sajithgsm]

@sajithgsm Thank you for following up, and thank you for the excellent image! It is helpful to hear that this is working as intended for you.

I am looking to understand cluster configuration more deeply, so I am still wondering what I am missing in comparing your setup with the documentation. It appears that "roles" actually represent relationships between the servers.

To use an example from your setup, when you go to cPanel Server 1 and there configure the role for DNS Server 1 as "synchronize", cPanel Server 1 says something to DNS Server 1, but I'm not really sure what it's saying. It could be, "I will push updates to you, but not without first asking you for recent changes and merging them with any changes that I didn't know about yet."

And when you go to DNS Server 1 and there configure the role for cPanel Server 1 as "standalone", DNS Server 1 says to cPanel Server 1, "I will receive updates from you but if I get a updates from another source, I will not push them out to you."

I suppose in that case, cPanel Server 1 will only receive updates from DNS Server 1 if it asks for them. This seems to make sense to get your cluster working, although I am not yet seeing how the "standalone" role is necessary. If all roles were "synchronize", would we not still have the most recent changes reaching the DNS servers with the added benefit of having the web servers kept up-to-date? And again, what of the documentation, which seems to suggest the roles be the reverse of @sajithgsm's setup?

when the beginning, I also keep used in reversed over 1 week and I had to manually sync all DNS again and again but I could not findout how to solve it. After that I set it as current setup, after that everything has been fixed and dns synchronization also become automatically.