At PDC09, Microsoft introduced two communication-related capabilities, that enable new application patterns in Windows Azure-hosted services:
- Inter-role Communication: While loosely coupled communication via Queues remains preferred method for reliable message processing, roles can now communicate directly using TCP, HTTP, or HTTPS connections. In addition, roles are notified as role instances within deployment’re added or removed, enabling elasticity. A common application pattern enabled by this’s client-server, where server could be an app such as a database or a memory cache.
- External Endpoints on Worker Roles can now contain external facing endpoints, or InputEndpoints, and you can bind to either directly in worker role or from within a process that you spawn from worker role. Unlike InternalEndpoints used by inter-role communication, InputEndpoints are load balanced. A common app type enabled by this’s a self-hosted Internet-exposed service, such as a custom app server.
More info: Windows Azure