Clustering

Striped, partially striped, and spotted configurations

By virtue of command propagation, all nodes in a cluster have the same configurations. However, you might want some configurations to be available only on certain cluster nodes. While you cannot restrict the nodes on which the configurations are available, you can specify the nodes on which the configurations are active.

For example, you can:

  • define a SNIP address to be active on only one node, or
  • define a SNIP address to be active on all nodes, or
  • define a VIP address to be active on only one node, or
  • define a VIP address to be active on all nodes, or
  • define a VIP address to be active only on two nodes of a 3-node cluster

Depending on the number of nodes the configurations are active on, cluster configurations are referred to as striped, partially striped, or spotted configurations.

Figure 1. Three-node cluster with striped, partially striped, and spotted configurations

Cluster partial striped

The following table provides more details on the types of configurations:

Configuration Type Active on Applicable to Configurations
Striped configuration All the cluster nodes All entries No specific configuration required to make an entity striped. By default, all entities defined on a cluster IP address are striped on all the cluster nodes.
Partially striped configuration A subset of cluster nodes Refer Cluster Node groups. Bind the entities that you want to be partially striped, to a node group. The configuration is active only on the cluster nodes that belong to the node group.
Spotted configuration Single cluster node SNIP address, SNMP Engine ID, host name of cluster nodes, Entities that can be bound to a node group A spotted configuration can be defined using one of two approaches. SNIP address When creating the SNIP address, specify the node on which you want the SNIP address to be active, as the owner node. Example, add ns ip 10.102.29.106 255.255.255.0 -type SNIP -ownerNode 2 (assuming node NS2 ID is 2). Note: You cannot change the ownership of a spotted SNIP address at run time. To change the ownership, you must first delete the SNIP address and add it again by specifying the new owner. Entities that can be bound to a node group. By binding the entity to a single-member node group.

Note

When you disable USIP, Citrix recommends you to use spotted SNIP addresses. You can use striped SNIP addresses only if there is a shortage of IP addresses. The use of striped IP addresses can result in ARP flux issues if no spotted IP addresses are present in the same subnet for ARP resolution.

When you enable USIP, Citrix recommends you to use striped SNIP addresses as a gateway for server initiated traffic.

ARP owner support for striped IP

In a cluster setup, you can configure a specific node to respond to the ARP request for a striped IP. The configured node responds to the ARP traffic.

A new parameter “arpOwner” is introduced in the “add, set, and unset ip” commands.

To enable the ARP owner on a node by using the CLI.

At the command prompt, type:

add ns ip <ip_address> -arpOwner <node_id>

Note

The ARP owner parameter is supported only in L2 cluster.

Neighbor discovery owner support for striped IPv6 address

In a cluster setup, you can configure a specific node as neighbor discovery (ND) owner for the striped IPv6 address to determine the link-layer address. A client sends a Neighbor Solicitation (NS) message to all the nodes in the cluster setup. The ND owner responds with a Neighbor Advertisement (NA) message with the link-layer address for the striped IPv6 address, and serves traffic.

To enable ND owner on a node by using the CLI

At the command prompt, type:

add ns ip6 <IPv6Address> -ndOwner <node id>

set  ns ip6 <IPv6Address> -ndOwner <node id>

Example:

add ns ip6 2001::21/64 -ndOwner 1

set ns ip6 2001::21/64 -ndOwner 1

To enable ND owner on a node by using the GUI

  1. Navigate to System > Network > IPs.
  2. In the IPs page, go to the IPv6s tab and click Add.
  3. In the Create IPv6 page, select one of the node IDs listed in NdOwner in Cluster drop-down menu.

Note

The ND owner parameter is supported only in L2 cluster.

Striped, partially striped, and spotted configurations