vCloud Director cells are stateless front-end processors for the vCloud. Each cell has a variety of purposes and self-manages various functions among cells while connecting to a central database. The cell manages connectivity to the vCloud and provides API and UI endpoints, or clients.

To improve availability and scale, implement a vCloud Director server group comprised of multiple vCloud Director cells. A multicell configuration requires load balancing or content switching of the front-end portal. Load balancers present a consistent address for services regardless of the underlying, responding node. They can spread session load across cells, monitor cell health, and add/remove cells from the active service pool. The cell architecture is not a true cluster because is no failover from one cell to another.

Any load balancer that supports SSL session persistence with network connectivity to the public-facing Internet or internal service network, such as the vCloud Networking and Security Edge Gateway, can perform load balancing of vCloud Director cells. Refer to general design guidelines regarding performance, security, manageability, and so forth when deciding to share or dedicate load balancing resources.

Note: SSL offloading does not work with console proxy connections (VMRC).

See Appendix A: Availability for additional load balancing considerations.