DNS Clustering Confusion

[Ray Hayes]

I have read so many articles that my eyes bleed. But, yet, no matter what I do, it seems DNSOnly is an issue.

My setup
1. Multiple Cpanel hosting nodes several locations
2. ONE DNSOnly elsewhere for failovers

Here is the config
ns1 (full cpanel node with hosting accounts)
ns2 (DNSOnly)
cpanel3, cpanel4, etc

Let just discuss a simple scenario...

On NS1, NS2 is set as 'WRITE ONLY'
On NS2, NS1 is set as 'STANDALONE'

So, any changes or syncs from NS1 should change records on NS2. Changes made on NS2 should be ignored (not making changes there anyways).

So, I deleted a ZONE on NS1, but it will not delete from NS2. I synced from both sides, but it will not disappear.

I will avoid discussing issues with cpanel3 and cpanel4 for now...I just need to understand the cluster dynamic, and why these changes do not appear.

 

[LucasRolff]

On ns1:
- Add your ns2 nameserver, and set it to "Synchronize changes" - do not add a reverse trust - there's no need for it.

on cpanel3,4,5.... (I assume full cPanel servers?):
- Add ns1 and ns2, set both to "Synchronize changes" - do not add a reverse trust - there's no need for it.

The I happen to do a similar setup, where my "ns1" is also a full cPanel server, and ns2, ns3, ns4 are all "DNS Only", and the easy way is to just keep it simple, and only add the servers from the cPanel machine that you expect zone changes to happen on.

But at least, skip the reverse trust part - there's no reason to trust the other way around

 

[Ray Hayes]

@LucasRolff

Thanks. And should I add ns1 to ns2 also, or just add ns2 to ns1 (as you noted) and be done?

Then the question arises...if I have a VPS with just a few accounts, but want to use ns1, ns2 as the main nameservers, do I add ns1 to the VPS as write only, which should write to ns1 and ns1 will sync the records to ns2? Thus, nothing from ns1 syncs to VPS?

Note: This is how I assumed it worked, but still see some issues at times...

thanks

 

[cPanelMichael]

Hello @Ray Hayes,

I recommend using the "Direct Links" example at:

Guide to DNS Cluster Configurations - cPanel Knowledge Base - cPanel Documentation

If you use "Synchronize" instead of "Write-Only" as the DNS roles, then it will prevent the creation of a DNS zone on your other web servers in the same cluster if the zone already exists (e.g. Customer on Web Server 1 can't create addondomain123.tld if a customer on Web Server 2 has already created addondomain123.tld). Here's an example of the direct link structure:

webserver1 >sync changes> dnsonly1
webserver2 >sync changes> dnsonly1
webserver3 >sync changes> dnsonly1

We do not recommend that you set up the nameserver to synchronize data to a web server, because this creates extraneous zones on the web server. This means that you do not need to log in to WHM on the nameserver and set the web server's DNS role to Synchronize changes.

Thank you.