- Behavior of Nodegroups
- Configuring Nodegroups for Spotted and Partially-Striped Configurations
Due to the interoperability of nodegroups with different NetScaler features and entities, there are some behavioral aspects to be noted. Nodes in a nodegroup can also be backed up. Read on for more information.
By default, a nodegroup is designed to provide back up nodes for members of a nodegroup. If a nodegroup member goes down, a cluster node that is not a member of the nodegroup dynamically replaces the failed node. This node is called the replacement node.
When the original member of the nodegroup comes up, the replacement node, by default, is replaced by the original member node.
From NetScaler 10.5 Build 50.10 onwards, however, the NetScaler allows you to change this replacement behavior. When you enable the sticky option, the replacement node is retained even after the original member node comes up. The original node takes over only when the replacement node goes down.
You can also disable the backup functionality. To do this, you must enable the strict option. In this scenario, when a nodegroup member goes down, no other cluster node is picked up as a backup node. The original node continues being part of the nodegroup when it comes up. This option ensures that entities bound to a nodegroup are active only on nodegroup members.