DNS Cluster on cPanel
cPanel is the most used control panel in the World through which we can manage our websites and settings easily via a User-Friendly interface. If you have more than one cPanel servers, it would be good to setup cPanel’s DNS cluster to lower the risk of a DNS failure on a nameserver taking down all of your sites. A DNS cluster is a service and it has a group of name servers that share records with each other. It allows physically separate nameservers that handle the domain name requests from web servers. In the event of, a power outage, currently you still have DNS functionality. In this way, visitors can easily get websites on your server more quickly after the web server comes back online. DNS resolves domain names to an IP address. This is one step in loading a website. In this type of instances DNS cluster will give a backup for name resolution. The requirements to setup DNS cluster is listed below:
1) At least two cPanel servers required with DNS running (bind).
2) The bind must have configured on port 53 on both server and accepting connection each other.
Let’s see the steps on how we can setup the DNS cluster on a cPanel server.
1) First thing is, you will need to enable DNS cluster on each server’s WHM interface. For this navigate to WHM Home >> Clusters >> DNS Cluster option on each server and enable the clustering by clicking on “Enable DNS clustering” button.
Once you have enabled the DNS clustering, you can see a new configuration there as “Global Cluster options”. This configuration decides when to drop a server from the cluster (if they are unresponsive to commands) and how many commands if they are unresponsive must be considered as server down. You can keep the default settings and can enable notification when a server is dropped from the DNS cluster.
2) For setting up the DNS cluster, select the Backend type as cPanel and then select “Configure” button there.
3) On the new interface enter the details of additional nameservers such as server IP on host field, username of the remote server, and SSH key of remote nameserver server. You can create the SSH key using the nameservers WHM interface.
Select the DNS role as ‘Synchronize Changes’ and click on submit button at the bottom. This means the changes made on this server will propagate to any server in the cluster that is linked to this server.
You will need to repeat the above same steps on another server too so that each server will be in sync.