An administrator needs to provision a PostgreSQL cluster instance with an external Load Balancer. Which software can be omitted on the Reference: VM while creating the Software Profile?
Correct Answer: B
When provisioning a PostgreSQL cluster instance with an external load balancer in NDB, the administrator creates a software profile from a Reference: VM. The Reference: VM typically includes software like Patroni (for HA management), HAProxy (for internal load balancing), keepalived (for high availability IP management), and etcd (for distributed configuration). Since an external load balancer is used, the internal HAProxy can be omitted from the Reference: VM.
NDB will rely on the external load balancer to distribute traffic, eliminating the need for HAProxy in the software profile, while the other components remain essential for cluster management.