A Comprehensive Guide for DNS Cluster Configurations

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A Comprehensive Guide for DNS Cluster
Configurations
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Table of Contents

• DNS Cluster
• DNS
• Web Hosting
• Managing DNS Clusters

• Cluster Members Failure Threshold
• DNS Cluster Requirements
• DNS Cluster Structures

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DNS Cluster

• A DNS (Domain Name System) cluster refers to a
  collection of nameservers. This groups shares
  records among each other. It serves the purpose
  of separating in physical form the nameservers
  that are handing the web servers DNS requests.
  It makes it possible to configure a DNS cluster,
  so that servers could be added to a DNS cluster
  that already exists.

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DNS

• DNS is the abbreviation of Domain Name System. It
  refers to the naming system used by computers and
  other resources that are connected to either a
  private network or to the Internet. It is
  decentralized as well as hierarchical. It is the
  DNS that ensures the delegation of the task which
  caters to the assignment of domain names and
  mapping those to Internet resources. Moreover,
  the more easily memorized domain names are
  translated by it to IP addresses that are
  numerical. These IP addresses are needed to
  locate and identify computer services and
  devices. The technical functionality of the
  service related to database is also specified by
  DNS.

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Web Hosting

• In the context of the Internet which is used to
  browse innumerable websites, web hosting is
  important to mention. Web Hosting refers to the
  leasing of server space along with providing the
  necessary service and technology to make a
  website accessible over the Internet. There are
  many website hosting service providers (also
  referred to as web hosts) that offer various
  plans for various types of web hosting, such as
  shared, dedicated, resellers, WordPress, cloud
  etc.
• The terms that are often heard in the context of
  web hosting are Top Cloud Hosting Company, the
  Best Website Hosting Company and the Best
  Windows Hosting Company. These refer to web
  hosts that excel in the quality of services
  provided by them.

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Managing DNS Clusters

• Those users who have the All ACL privilege are
  able to add to a DNS cluster their own custom DNS
  servers. Such users who possess this privilege
  also have the ability to make changes to the
  cluster members that exist. Modifying DNS cluster
  settings involves choosing between managing ones
  DNS clusters as the root user or in the form of a
  reseller from the Managing DNS Cluster as menu.
• Prior to the addition of custom DNS servers or
  making changes to existing cluster members, one
  is supposed to choose the root setting that is in
  the Managing DNS Cluster as menu.

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Cluster Members Failure Threshold

• The failure threshold with regard to cluster
  members setting enables the user to specify that
  particular number of DNS Admin commands that are
  allowed to fail, prior to WHM disabling a DNS
  cluster member that is unresponsive. It is
  advisable to disable an unresponsive DNS cluster
  member in order to aid improvement in
  performance.
• The steps that need to be followed in order for
  the failure threshold for cluster members
  setting to be configured are mentioned below-
• Step 1- Selection of the desired setting. A user
  should opt for 10 (Default) to use the default
  setting. In this setting a cluster member is
  permitted to fail DNS Admin commands up to 10
  times. It is usually recommended to use this
  setting. Next the second setting should be
  chosen, so that the custom failure threshold
  could be entered. It is advisable to increase the
  count for failure number in those situations
  where the server down time is frequent and
  network interruption happens frequently. This
  ensures that certain cluster members are not
  marked offline by the system. If the user wants
  to keep all of the servers in his DNS cluster
  online perpetually and doesnt want to consider
  the number of DNS Admin commands that have
  failed, then he should opt for Keep all cluster
  members online at all times

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Cluster Members Failure Threshold

• Step 2- Receive a notification when WHM disables
  an unresponsive cluster member option should be
  selected in order to receive notifications in
  that case when an unresponsive member in the DNS
  cluster is disabled. Disabled cluster members
  must be enabled manually.
• Step 3- The option to change must be clicked. In
  the scenario when any cluster member that is in
  the sync role is found to be offline for a very
  long period of time, the other servers zones
  need to be resynchronized. This keeps the cluster
  member updated.

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DNS Cluster Requirements

• Certain minimum requirements need to be met
  in order to configure a DNS cluster. These are
  mentioned below-
• A minimum of 2 servers must be present in the
  clusters.
• There must be at least 1 cPanel and WHM server
  present with cPanel and WHM installed. A scenario
  involving a DNS cluster that has more than 1 of
  these, also functions properly.
• Every machine that is in the DNS cluster needs to
  have cPanel and WHM or have a version 11 or
  higher of cPanel DNS Only installed. This is
  necessary as some of the features of cPanel and
  WHM might not function with versions that are
  old.
• The most efficient structure should be considered
  prior to setting up the DNS cluster. The speed of
  resolution of DNS requests is determined by the
  way in which each server is linked.
• To digress, terms such as Top Cloud Hosting
  Company, the Best Website Hosting Company and
  the Best Windows Hosting Company are used for
  those web hosts that provide reliable web hosting
  services.

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DNS Cluster Structures

• Direct links should be used- When there are
  multiple steps present between a cPanel and WHM
  and a nameserver, then the speed of servers tend
  to decrease. It is advisable to link cPanel and
  WHM server to the DNS servers directly, in order
  to enhance the performance of the servers. This
  ensures the elimination of the steps performed by
  every request. Hence, the DNs requests get
  resolved swiftly. It is optimal to have a direct
  link between each of the 2 nameservers and the
  web server. Such a configuration can be created
  by one cPanel and WHM server with the need for
  nameservers that can be one or more in number.
• The primary nameserver should be used as an
  intermediary- If the need arises, the primary
  nameserver can be placed between the cPanel and
  WHM server and the nameserver that is secondary.
  Any intermediate server that gets added will slow
  the data transfer speed to three times in
  comparison with that for a direct link. An
  intermediate nameserver that is present between
  the web server and that nameserver that is
  secondary is admissible. For the creation of such
  a configuration, one cPanel and WHM server with a
  minimum of 2 nameservers is needed.
• Multiple intermediary nameservers should be used-
  In this configuration multiple steps are used
  between WHM server and cPanel and nameservers. A
  minimum of two cPanel and WHM servers along with
  a minimum of two nameservers is needed for the
  creation of this configuration. Such a
  configuration is known to reduce the servers
  response time significantly. This is not a method
  that is advisable as it reduces performance
  considerably.

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