Communication within Application Systems

In System Designer, you can configure communication pathways between the members of a system by connecting them. On a system diagram, connections describe how applications are connected when an instance of the system is deployed. Connections on system diagrams are also instructions for configuring consumer endpoints with the addresses assigned to provider endpoints, for example, Web service URLs.

By comparison, connections on the application diagram represent how applications are connected in the development environment, based on the actual configuration of consumer endpoints.

For more information, see the following topics:

Configuring Communication Pathways on System Diagrams

On a system diagram, you configure and connect members of a system as necessary and appropriate for that system. For example, you do not need to configure and connect application members in the same way that their underlying definitions are connected on the application diagram or on other system diagrams. You can configure communication pathways on a system diagram by connecting endpoints on members of the system.

In contrast to the application diagram, endpoints on members of a system definition must be already be defined for you to connect them. For example, you can connect systems within a system definition only if those systems expose the behavior of their members through proxy endpoints. While you can connect, disconnect, and override settings on endpoints, you cannot add or remove endpoints from members in a system definition. To add or remove endpoints from members, you must add or remove them on the diagrams that define those members. Otherwise, the rules for connecting members of a system are similar to those on the application diagram.

In addition, a consumer endpoint on a member typically requires a connection to a suitable provider endpoint or a delegation to a proxy endpoint in order for the member to function correctly. On the application diagram, the definition of a consumer endpoint has a Connection Required application endpoint setting, which is set to True and is not overridable by default when a use of the associated application is included in a system. However, if the application's implementation requires the connection to be optional, you can change this setting to False on the definition or override the setting within the context of a system. Otherwise, the consumer endpoint must be connected or delegated for the system to be valid.

Note

If a Web service consumer endpoint is disconnected when a connection is required, the endpoint will not be configured at deployment, and a validation error will result when evaluating deployment for the system. The only time a connection should not be required is when the application can be deployed and used without configuration information, which is not the usual case.

For more information, see the following topics:

See Also

Tasks

How to: Delete Endpoints from System Diagrams

How to: Reroute and Redraw Connections on System Diagrams

Other Resources

Defining Communication Pathways on System Diagrams