You can deploy a set of three NSX Advanced Load Balancer Controllers as a High Availability cluster, as a best practise. In a cluster deployment, one of the Controllers acts as a leader. It performs load balancing and configuration management for the cluster. While the other two Controllers are followers, they collaborate along with the leader to perform data collection from SEs and process analytics data.
High Availability for NSX Advanced Load Balancer Controllers
NSX Advanced Load Balancer can run with a single Controller (single-node deployment) or with a three-node Controller cluster. In a deployment that uses a single Controller, that Controller performs all the administrative functions, it also gathers and processes all the analytics data.
You can create a three-node cluster by adding two additional nodes. This three-node cluster provides a node-level redundancy for the Controller and maximizes performance for CPU-intensive analytics functions. However, for a single Controller in a single-node deployment, it performs all administrative functions; collects and processes all the analytics data. These tasks are distributed in a three-node cluster.
In a three-node Controller cluster, one node is the primary (leader) node and performs the administrative functions. The other two nodes are followers (secondaries), and perform data collection for analytics, in addition to standing by as backups for the leader.