EMS Channels in a Cluster

When eFTL services cooperate in a cluster, their corresponding EMS channels do not forward messages across the cluster. Instead the EMS server forwards messages to the corresponding channels in each eFTL service.

Figure 11: EMS Channels in a Cluster

The diagram illustrates a cluster of two eFTL services. The purple arrow indicates that when Pub_B1 sends a message, Service_1 translates it and forwards it the EMS server. The EMS server forwards it in two directions:

• The downward black arrow indicates delivery to EMS subscribers, such as Sub_B2.
• The upward blue arrows indicate delivery to channel B of both eFTL services, which translate the message again, and forward it to eFTL subscribers, such as Sub_B1 and Sub_B3.

When EMS publisher Pub_B2 sends a message, the EMS server forwards it over same upward paths.