Manage the Round Robin Polls

The round robin is a load balancing technique in which balance power is placed in the DNS server instead of a strictly dedicated machine as other load techniques do. Round robin works on a rotating basis in that one server IP address is handed out, then moves to the back of the list; the next server IP address is handed out, and then it moves to the end of the list; and so on, depending on the number of servers being used. This works in a looping fashion.

The Round Robin Polls for DNS {zone_name} management page allows you to:

• Visualize the Current Polls.
• Define a New Round Robin Poll by clicking the Add new poll icon.
• Search for certain polls.
• Edit one of the existing round robin polls.
• Remove unused polls.

The page displays the following information about the available polls:

• S - The round robin poll's status (enabled or disabled). Click the icon to modify the poll's status.
• Name - The round robin poll's name. Click the link to edit the poll.
• Monitored records - The number of monitored records.
• Active records - The number of active records out of the total monitored records.
• Last update - The date and time the poll was last updated.

Add a New Round Robin Poll

Follow the next steps to add a new poll:

Use the controls available in the Add New Resource Poll fieldset to define the poll's behaviour:

• Name - fill in the poll's name

• Tested protocol - the list of tested protocols. The available options are:

  • HTTP
  • IMAP
  • MySQL
  • PING
  • POP3
  • SIP
  • SMTP

• Monitoring interval - the number of minutes between two subsequent tests

• Tested resource - specify a resource corresponding to the protocol that is to be tested. You can type in a particular IP address or hostname or you can monitor the value set for the selected records. For the later, use the $RR variable.

  $RR is replaced by one of the entries in the Value column listed for the selected records. You can use expressions such as http://$RR or http://$RR.php.

• Try resource for {x} seconds - decide for how long the round robin will attempt to access the resource before failing.

Next, choose the DNS record(s) you wish to add to the poll from the DNS Records table by selecting the corresponding check box(es) available in the M column. If you want to select all the records in the list, then simply select the check box displayed in the top header.

Click the Apply changes link to associate the selected records with the new poll.

To finalize the process, click OK and return to the previous page. Click Cancel if you do not want to create the round robin poll.