What is chaining of event channels? Why chain event channels?
Event channels are themselves suppliers and consumers of events. As such, they can be chained together.Consider the following scenario: a supplier supplies events to multiple nearby consumers and to multiple distant consumers that are located far away over a slow communication link. If the event channel is located near the supplier, the expensive communication takes place for each distant consumer. On the other hand, if the event channel is located near the distant consumers, the expensive communication takes place for each local consumers. The solution is to used two chained event channels: one near the local consumers and another near the distant consumers. This way the event only travels over the slow communication link once.