Use Endpoint Groups to Configure Connectivity in Windows Azure Connect

The following diagram, which is also shown in Overview of Windows Azure Connect, shows two endpoint groups that each have a single connection to a Windows Azure role. The yellow dots mark local endpoints, that is, computers on which Windows Azure Connect has been installed, and the yellow dotted lines outline the endpoint groups.

The endpoint group that contains development computers is connected to Worker Role 1. This means that each development computer can communicate with any role instances in Worker Role 1. Similarly, the endpoint group that contains database computers is connected to Web Role 1. Each database computer can communicate with any role instances in Web Role 1.

Endpoint groups that have a single connection

The following diagram expands the configuration for the database computers shown in the previous diagram. The database computers are still in the same endpoint group. However, that endpoint group includes not only Web Role 1, but also a new Web role called Web Role 3. This means that each database computer can communicate with any role instances in either Web Role 1 or Web Role 3.

Endpoint groups where one group has multiple connections

Note that Windows Azure Connect is not designed to support direct connections between instances in Windows Azure roles—in the diagram, this would be connections between instances in Web Role 1 and instances in Web Role 3. Use other functionality in Windows Azure for such connections.

The following diagram expands the configuration for all computers shown in the previous diagram. The computers are still in the same endpoint groups as they were in previous diagrams. However, the endpoint group that contains development computers now has a connection to Web Role 3, and also has a connection to the other endpoint group. The endpoint group that contains database computers is connected to the same roles as in the previous diagram.

Endpoint groups that use multiple connections

The diagram shows that each local endpoint can be assigned to only one endpoint group. However, the diagram also shows that:

• Multiple Windows Azure roles can be assigned to one endpoint group. For example, both Web Role 1 and Web Role 3 are assigned to the endpoint group that contains database computers.
  
  
• Multiple endpoint groups can include a given Windows Azure role. For example, both endpoint groups include Web Role 3.
  
  
• An endpoint group can have a connection to another endpoint group. For example, the endpoint group that contains development computers has a connection to the endpoint group that contains database computers.
  
  

Note

With Windows Azure Connect, connections are point-to-point, not linked up in a series of multiple connections. Therefore, in the preceding configuration, even though the two endpoint groups are connected, the development computers (on the left) do not have a connection to Web Role 1 (on the right). Similarly, the database computers (on the right) do not have a connection to Worker Role 1 (on the left).

The following diagram shows what happens when you enable interconnections among the systems in a group of endpoints. One development computer is in the central corporate network, and one development computer is outside that network, at a branch location. Both development computers are connected to Worker Role 1, and interconnection has been enabled, which means that the development computers can use Windows Azure Connect to connect to each other. With this configuration, whenever both development computers are connected to the Internet, they will have a connection to each other.

Endpoint group that uses interconnections