Performance Improved in cPanel 11.25 DNS Clustering
cPanel DNS clustering utility, DNSAdmin, now sends updates in batches with a single call, reducing the server’s memory consumption during DNS synchronization.
cPanel have also added a feature that will automatically disable unresponsive cluster members, preventing outdated information from being sent to up-to-date servers when the unresponsive server come back online. Plus, cPanel simplified reconfiguring and restarting BIND into a single call, speeding up the process.
DNS Clustering dnsadmin operations.
Certain dnsadmin operations are now performed in batches. This reduces both the memory needed during large operations, and the amount of time needed to perform the operation.
Each cPanel™ 11.25 cluster member may now configure a peer failure threshold. This option is found in the Configure Cluster interface in WHM. The threshold specifies how many dnsadmin commands a peer may fail to respond to before that peer is automatically disabled. The threshold is local to the server where it is stipulated.
By default, each cPanel™ 11.25 cluster member will notify the system administrator when peers are disabled due to reaching the failure threshold. The notifications are sent to the High priority destinations as set in the Contact Manager in WHM.
The amount of time between BIND restarts issued by dnsadmin is configurable via a new option in the WHM Tweak Settings interface.
cPanel’s DNS clustering
cPanel’s DNS clustering allows you to synchronize DNS records between multiple cPanel or cPanel DNS ONLY machines. In order to synchronize your DNS records, all machines in the cluster must be running cPanel or cPanel DNS ONLY versions 8.9 or higher.
When configuring your server cluster, it is important to minimize the amount of hops between servers to create the shortest path possible. When possible, you should link webserver server directly to your dns servers or any other servers you wish to update. Each time a DNS zone is modified, the modification will travel down the path to reach each server in the path. The performance of the system is directly proportional to the length of the path.
Notes:
Synchronize Changes: All changes made on your webserver server will be replicated to any server linked to the webserver in the cluster.
Synchronization is one-way: Changes made on the other server will not be replicated to webserver server unless Synchronize Changes is selected on that server as well.
Standalone: All changes made on webserver server will not replicated to any other server(s).
Enabling DNS clustering on each server
A DNS cluster is a number of nameservers that share records. To optimally configure your DNS cluster, you will need 2 spare servers, both preferably running cPanel DNS ONLY. You will also need at least 1 web server with cPanel/WHM installed.
You can download the cPanel DNS ONLY software here.
http://layer1.cpanel.net/cpanel-dnsonly-install.sea
All machines in the cluster must be running cPanel or cPanel DNS ONLY version 11 or higher. Some features may not work with older versions of cPanel.
Enabling DNS clustering on each server
First, you will need to enable DNS clustering via each server’s WHM interface.
1. Navigate to WHM’s Configure Cluster screen.
2. Click Enable Dns Clustering.
3. Click Change.
4. Click Return to Cluster Status.
Next, you will need to specify which server(s) you wish to cluster, or share DNS information with.
You do not need to link dedicated DNS servers to each other, or link dedicated web servers to each other.
You will need to sync each web server to its DNS servers.
You should not set a DNS server to sync data back to a web server, as this will put extraneous data on the web server.
Enabling DNS clustering on cpanel server
First, you will need to enable DNS clustering via each server’s WHM interface.
You will need to sync each web server to its DNS servers.
You do not need to link dedicated DNS servers to each other, or link dedicated web servers to each other.
You should not set a DNS server to sync data back to a web server, as this will put extraneous data on the web server.
Steps:
1. Navigate to WHM’s Configure Cluster screen.
2. Click Enable Dns Clustering.
3. Click Change.
4. Click Return to Cluster Status.
DNS clustering is now enabled. Next, you will need to specify which server(s) you wish to cluster, or share DNS information with.
