Microsoft is using Linux to run its cloud

Microsoft Corporation is an American multinational technology company headquartered in Redmond, Washington, that develops, manufactures, licenses, supports and sells computer software, consumer electronics and personal computers and services.

Redmond's revealed that it's built something called Azure Cloud Switch (ACS), describing it as “a cross-platform modular operating system for data center networking built on Linux” and “our foray into building our own software for running network devices like switches.”

Both the cloud and the enterprise depend on high-speed, highly available networks to power their services. This makes it critical for network operators to be able to control their own destiny by rapidly adding to their network features they need while keeping out feature changes that increase risk and complexity.

ACS also allows Microsoft to share the same software stack across hardware from multiple switch vendors. This is done via the Switch Abstraction Interface (SAI) specification, the first open-standard C API for programming network switching ASICs, of the Open Compute Project (OCP). Microsoft was a founding member of the SAI effort and remains a leading contributor to the project as we view SAI as an instrumental piece to make the ACS a success.

While the ACS respects and learns from the experiences of years of quality switch software stacks, it deviates in many aspects from conventional switch software stack to achieve some of the objectives just highlighted.

Traditional switch software is built for several customers with several scenarios and feature requests. Since the ACS focuses on feature development based on Microsoft priorities, it has a Lean Stack. The thin software stack focuses on software needed for our Datacenter Networks and strives to fix, test and remediate network device software bugs faster than the current run rate. The ACS is also a Modular Stack as opposed to one monolithic image. The advantages of a lean and modular stack are plenty. It makes validation easier with less probability for hidden, high priority bugs and reduces new feature request time lag.

ACS believes in the power of Open Networking. ACS together with the open, standardized SAI interface allows us to exploit new hardware faster and enables us to ride the tide of ASIC innovation while simultaneously being able to operate on multiple platforms. Running on Linux, ACS is able to make use of its vibrant ecosystem.

"The company writes, “At Microsoft, we believe there are many excellent switch hardware platforms available on the market, with healthy competition between many vendors driving innovation, speed increases, and cost reductions.”