Azure networking feature addresses latency, performance

Microsoft's latest networking update helps stabilize workloads and accelerate packet transactions on its public cloud -- and brings a new weapon onto the latest cloud provider battlefield.

Accelerated Networking, a free service now generally available in Microsoft Azure for Windows and Linux users, uses Microsoft's move to field-programmable gate arrays (FPGAs) and can reduce latency and other networking hiccups. It's also the latest in a series of upgrades from the major public cloud providers as they emphasize their platforms' networking capabilities.

Accelerated Networking, available in all Azure regions, provides up to 30Gbps throughput by moving the Azure networking stack from the hypervisor down to the smart network interface controllers (SmartNICs). It's akin to Amazon Web Services' enhanced networking feature, which is also free and available for Linux and Windows.

Brad Casemore

Bypassing the hypervisor to directly interface with the NIC should boost performance and cut jitter, in addition to latency benefits, said Murali Basavaiah, co-founder and vice president of engineering at Avi Networks, which provides application load balancing on premises and in the public cloud. Elimination of CPU-tied networking reduces compute cycles and load per VM, which ultimately translates to lower cost for customers and greater overall efficiency in Microsoft's data centers.

There is a hitch to the service, however. It's currently limited to a handful of options in the D, E, F and M series of VMs, and can't be used with older VM types. Customers must also use a new NIC, which cannot be attached to an existing VM, or to an availability set if any of the VMs in the group aren't Accelerated Networking-enabled. It also can only be deployed through the Azure Resource Manager.

Applications that will benefit the most from Azure Accelerated Networking are smaller, transactional workloads ... but an instance with large packet transfers, for example, would see less latency with a virtual switch.

In a bit of good timing, Microsoft made Accelerated Networking generally available in the wake of its response to the Spectre and Meltdown chip vulnerabilities. Microsoft initially said some Azure workloads would see slower performance due to security patches but, following the patches, it said Accelerated Networking should make up the difference for those users.

Applications that will benefit the most from Azure Accelerated Networking are smaller, transactional workloads, but this new tool is not a cure all, said Scott Harvey, vice president of engineering at Atmosera, an Azure managed service provider in Beaverton, Ore. An instance with large packet transfers, for example, would see less latency with a virtual switch because it wouldn't have to map additional hops required to break down large chunks of data to accommodate the capacity limits of a physical controller.

He's also dubious of Microsoft's claims that Accelerated Networking can unilaterally address performance issues related to these chip defects. "It certainly will have its benefits, but those would be there whether Spectre and Meltdown were in play or not," Harvey said.