DNS Load Distribution

When you use a scale-out cluster configuration (see Configure Scale-Out NAS Clusters), you can enable DNS Load Distribution to start a DNS server on the master node for the zone represented by the cluster hostname. This DNS server allows you to provide an IP address based on the number of SMB connections to each node.

Note: For a list of all the Appliance Controller commands, see the Command Index.

  1. Log in to the Appliance Controller CLI.

  2. At the prompt, enter the following command to enable DNS load balancing:

    > nascluster dns enable

    Checking configuration ...

    NAS Cluster enabling DNS ...

    Applying DNS settings ..

    Broadcasting share config-sync to NAS cluster ...

    Waiting for nascluster_share_config_sync to complete on node 192.168.16.11

    Waiting for nascluster_share_config_sync to complete on node 192.168.16.12

    Successfully modified NAS cluster DNS

  1. Log in to the Appliance Controller CLI.

  2. At the prompt, enter the following command to disable DNS load balancing:

    > nascluster dns disable

    Checking configuration ...

    NAS Cluster disabling DNS ...

    Applying DNS settings ..

    Broadcasting share config-sync to NAS cluster ...

    Waiting for nascluster_share_config_sync to complete on node 192.168.16.11

    Waiting for nascluster_share_config_sync to complete on node 192.168.16.12

    Successfully modified NAS cluster DNS

  1. Log in to the Appliance Controller CLI.

  2. At the prompt, enter the following command to display the current DNS balancing configuration and status:

    > nascluster dns balancing show

    Balancing type: leastconn_node

    NODE connections:

      10.65.163.163   (weight=1)    :  10
  10.65.163.164   (weight=1)    :  11

VIP connections:
  10.65.164.76    :  10
  10.65.164.77    :  11

By default, the balancing type is set to leastconn_node; however, you can configure the balancing type to random, as follows.

  1. Log in to the Appliance Controller CLI.

  2. At the prompt, enter the following command to configure the balancing type:

    > nascluster dns balancing set random

    Successfully modified NAS cluster load balancing

By default, the leastconn_node balancing type assumes you need to spread the load evenly across all nodes; however, in some cases you might want to provide more node weight to specified nodes that can handle more connections.

For example, an Xcellis Workflow Extender can handle more connections than an Xcellis Workflow Director. The node weight allows you to configure the DNS server to send more connections to a specified node.

  1. Log in to the Appliance Controller CLI.

  2. At the prompt, enter the following command to configure the node weight:

    > nascluster dns set weight 10.65.163.163 2

    Successfully modified NAS cluster load balancing

    Note: A weight of zero (0) is a special configuration that is valid in all balancing types. You can use it to disable any new connections to a node when you are troubleshooting, or have to plan for maintenance.

  3. (Optional) At the prompt, enter the following command to display the current DNS balancing configuration and status:

    > nascluster dns balancing show

    Balancing type: leastconn_node

    NODE connections:

      10.65.163.163   (weight=2)    :  8
  10.65.163.164   (weight=1)    :  4

VIP connections:
  10.65.164.76    :  8
  10.65.164.77    :  4