A DNS cluster is a number of nameservers that share records. This allows you to physically separate your nameservers, so that in the event of, for instance, a power outage, you still have DNS functionality. Nameservers in different locations, using different providers, in different data centers, and on different uplinks removes the DNS single point of failure issue with using a DNS server on your hosting machine. This way, visitors can reach websites on your server more quickly after the web server comes back online.
DNS cluster requirements
To configure your DNS cluster, you must meet the following minimum requirements:
- Clusters must include at least two servers.
- You must have at least one web server with cPanel & WHM installed. A DNS cluster that includes multiple cPanel DNSONLY servers and cPanel & WHM servers is also acceptable.
- All machines in the DNS cluster must have cPanel & WHM or cPanel DNSONLY version 11 or higher installed. Some features may not work with older versions of cPanel & WHM.
As per the setup, we are hosting our domains in a server with cPanel & WHM and use it as Primary name server (ns1.configpixel.com) for the domains hosted. Add a new DNSONLY cPanel server to cluster and configured as secondary name server (ns2.configpixel.com ).
cPanel Hosting Server - server1.configpixel.com DNSONLY cPanel Server - dns1.configpixel.com
Name servers used are
ns1.configpixel.com - Point to server server1.configpixel.com ns2.configpixel.com - Point to server dns1.configpixel.com
How to enable Clustering ?
Enable Clustering in server1.configpixel.com
- Go to “DNS Cluster” under Clusters and Enable DNS clustering via WHM
- Add a new server to the cluster
- Select “Backend Type” as cPanel and click on Configure
- And enter “Host”, “username” ( root on most of the case ) and “Remote server access hash”
- Go to second server dns1.configpixel.com and go to “Remote Access Key” to get the “Remote server access hash”
- Enable “Setup Reverse Trust Relationship”
- Enable “Debug”, if debugging required
- Select “DNS Role” as “Synchronize Changes”
- Click on “Submit” to add.
- After adding the cluster, sync the records using “Synchronize DNS Records” from WHM after selecting “Synchronize all zones to all servers”, so that all the dns zones will copied to the secondry DNSONLY cPanel Server.
- Zero% downtime due to DNS service being down. If the DNS service is down in the server, the domain DNS will be served by the other servers in the cluster.
- If your DNS is served by a cluster of servers, and your website server is down, then your mail is queued by the sender’s mail server, instead of being “returned to sender” due to delivery failure. Once your site comes back online your mail is then delivered.
- It is easy to transfer domains among servers. The client will not have to change the nameservers used by the domains. The same nameservers can be used to point the domain to the new server.
- The response time to your website is shortened, since resolvers (usually) query the closest namservers to provide your user’s browser with your website’s IP address.
- You can use Global nameservers for all your servers. No need to set specific nameservers for each server.