Note that some production environments do not support multicast. However, if your environment supports multicast, there are no issues in using this as your membership scheme.
In the example below, we use the WKA membership scheme, and the ELB acts as the well-known member in the cluster. It will accept all the service requests on behalf of the ESB instances and divide the load among worker nodes in the ESB cluster.
The Well-Known Addresses (WKA) feature is a mechanism that allows cluster members to discover and join a cluster using unicast instead of multicast. WKA is enabled by specifying a small subset of cluster members (referred to as WKA members) that are able to start a cluster. The WKA member starts the cluster and the other members join the cluster through this WKA member. If the WKA member is down, the cluster breaks, and the members will not be able to communicate with each other.
The system should have at least two well-known address (WKA) members in order to work correctly and to recover if a single WKA member fails.