Windows Azure provides three core components, Compute, Storage and the Fabric, along with the Fabric controller. Compute is effectively the Windows operating system, this is an instance. These instances contain a copy of your application. Instances also come in two flavours, a Web Role or a Worker Role. Web roles accept and process HTTP requests using IIS. Not everything you may want to run in Windows Azure is a Web application, so Windows Azure also provides Worker roles. A Worker role instance is quite similar to a Web role instance. The key difference is that a Worker role does not have IIS preconfigured to run in each instance. Web and Worker roles can communicate with each other via technologies like WCF, or using Windows Azure Storage queues.
anonymous on 02 Mar 09Cloud services are being talked up as a fundamental shift in web architecture that promises to move us from interconnected silos to a collaborative network of services whose sum is greater than its parts. The problem is that the protocols powering current cloud services; SOAP and a few other assorted HTTP-based protocols are all one way information exchanges. Therefore cloud services aren't real-time, won't scale, and often can't clear the firewall. So, it's time we blow up those barriers and come to Jesus about the protocol that will fuel the SaaS models of tomorrow--that solution is XMPP (also called Jabber) .
