This use pattern shows the potential to deploy a WS-Notification service across multiple servers in a network deployment environment. In this pattern applications can connect to any WS-Notification service point and use them identically when inserting notifications, because WS-Notification topic namespaces are shared by all the WS-Notification service points of the WS-Notification service. Notification messages are propagated throughout the bus to any interested NotificationConsumers, regardless of the location where they attached to the bus (that is, regardless of the WS-Notification service point to which they are connected).
In the following diagram, the three servers (server1, server2 and server3) are configured with service points for the same WS-Notification service. Note that by implication (because of the scope of a WS-Notification service) these three servers are all bus members of the same service integration bus.
In the following figure, a cell contains three application servers, and each application server contains a WS-Notification service and messaging engine. All three messaging engines within the cell are linked. Consequently, requests received by any server in the cell, are available to consumers associated with any other server in the cell.
This use pattern allows you to distribute your clients across multiple servers, and thereby share the load amongst these servers. In this use pattern, you manually configure the balancing of applications. An alternative approach is to use workload distribution across the servers in a cluster, as described in the Load balanced use pattern.