One of the differences, however, between enterprise and cloud is that in the enterprise, a critical application typically runs on a large server and gets more of the server as it "scales up" to meet the increased demand. In the cloud, there are only commodity servers, and its necessary for the AppFabric to "scale out" to meet demand. Usually, Parasnis said, that means committing additional servers to run additional instances of the application and load balance traffic across them.
AppFabric for Azure will include access control services, and service bus services, where messages between applications can be delivered over the service bus, getting reformatted enroute if necessary. Both were part of Microsoft's previous approach to services oriented architecture, called Oslo.
The next major release of Microsoft's BizTalk Server will take advantage of Azure AppFabric capabilities, linking composite applications with parts found in the enterprise and in the cloud. BizTalk Server already connects the Windows environment to outside applications, such as SAP's and Oracle's. It connect to major database systems. It's next release will support Windows Workflow Foundation, while tying into Azure AppFabric services, creating possible scenarios where workflow will move from the enterprise into the cloud and back again.
Underneath AppFabric services is something called the Azure fabric controller, not a separate product but part of the infrastructure, providing an ability to execute workflows and instructions across loosely coupled systems in both the enterprise and in the cloud as well.
AppFabric in both its Windows Server and Azure incarnations is an enabler, a provider of services to application business logic that knows what it wants to do but may not know how to connect to the next step in a process, or how to activate an ally in completing the process.
"This is the next big shift in applications," said Parasnis amidst the hubbub of thousands of Windows developers moving from session to session in the L.A. Convention Center Tuesday. "Instead of being bound to one big server, applications will run on hardware at the scale the developers wants." And that means it will scale-out when the demand is there and scale back as it recedes.
It's Microsoft's view, according to Bob Muglia, president of the Servers and Tools unit, that this elasticity should be available in the enterprise, even though it hasn't always been in the past and it will work to make that happen. But Microsoft wants to insure that it certainly will be available in the Azure cloud, through AppFabric.
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