NSX Advanced Load Balancer Controller clusters provide high availability (HA) and redundancy, as well as increased analytic workload scale.
NSX Advanced Load Balancer Controllers communicate with each other over a single management IP address, the cluster IP address. They also use this path to communicate with all NSX Advanced Load Balancer Service Engines (SE) within the fabric.
The Controllers are not required to exist within the same IP network, but here are a few generic limitations to be considered:
The Controllers must be within the same region (ideally the same data center). This helps in quickly synchronizing the databases and perform actions such as, log indexing and data retrieval.
The Controllers have the option of sharing a cluster IP address. The cluster IP address is owned by the primary NSX Advanced Load Balancer Controller within the cluster. In order to share an IP address, all the Controllers must have a NIC in the same network.
Each NSX Advanced Load Balancer Controller must have access to the IP addresses of other NSX Advanced Load Balancer Controller through configured network routes.
Considerations for AWS
Availability Zones (AZs) provide redundancy and separate fault domains. All AWS regions support a minimum of two AZs. To leverage high availability provided by AWS AZs, it is recommended to deploy different NSX Advanced Load Balancer Controller instance of a cluster in different AZs.
It is recommended to deploy a cluster of three NSX Advanced Load Balancer Controller instances. Once the NSX Advanced Load Balancer Controller cluster is formed, the controllers synchronize the state, irrespective of the controller instance used to configure NSX Advanced Load Balancer features or retrieve operational data.
For more details on the Controller cluster architecture and configuration, see HA for Avi Controllers.
