Nodegroups for spotted and partially-striped configurations
By virtue of the default cluster behavior, all configurations performed on the cluster IP address are available on all nodes of the cluster. However, there might be cases where you need some configurations to be available only on specific cluster nodes.
You can achieve this requirement by defining a nodegroup that includes the specific cluster nodes, and then binding the configuration to that nodegroup. This ensures that the configuration is active only on those cluster nodes. These configurations are called partially-striped or spotted (if active only one a single node). For more information, see Striped, Partially Striped, and Spotted Configurations.
For example, consider a cluster with three nodes. You create a nodegroup NG0 that includes node n1 and another nodegroup NG1 that includes n2 and n3. Bind load balancing virtual servers .77 to NG0 and load balancing virtual server .69 to NG1.
This means that virtual server .77 will be active only on n1 and consequently only n1 will receive traffic that is directed to .77. Similarly, virtual server .69 will be active only on nodes n2 and n3 and consequently only n2 and n3 will receive traffic that is directed to .69.
Figure 1. NetScaler cluster with nodegroups configured for spotted and partial-striped configurations
The entities or configurations that you can bind to a nodegroup are:
- Load balancing, content switching, cache redirection, authentication, authorization, and auditing virtual servers.
FTP load balancing virtual servers cannot be bound to nodegroups.
- VPN virtual server (Supported from NetScaler 10.5 Build 50.10 onwards).
- Global Server Load Balancing (GSLB) sites and other GSLB entities (Supported from NetScaler 10.5 Build 52.11 onwards).
- Limit identifiers and stream identifiers.