Walmart's advice to companies trying to control the hefty cost of running workloads on the three largest cloud providers comes down to one word: choice.
Tying your IT wagon to only AWS, Microsoft Azure, or Google Cloud will likely lead to higher costs than having the option to run workloads on at least two platforms, said Kevin Evans, vice president of infrastructure services at the world's second-largest retailer behind Amazon.
"Regardless of your size, having choices will help you manage the costs," he said.
Walmart built one of the world's biggest hybrid clouds on an architecture designed to run a workload on Azure, Google Cloud or the Walmart Cloud Native Platform -- a Kubernetes-based system the company built from the ground up in 2020.
Azure and Google's public clouds have AI and other services Walmart prefers to rent than build. But, in general, the three IaaS platforms are equal with one critical difference: Walmart can deliver to its developers computing, storage and network resources for less.
"We can do it at a much lower cost," Evans said.
Walmart neutralizes cloud differences
The heart of Walmart's multi-cloud architecture is the Cloud Native Platform's abstraction layer that hides from developers the differences between spinning up resources on the three platforms.
Kevin EvansVice President of Infrastructure Services, Walmart
On top of the abstraction layer is a common interface that relieves developers of the arduous tasks of learning different storage and disk types and terminology for computing resources. The universal interface lets developers deploy and move workloads using nearly the same procedures.
"Our workloads become agnostic," Evans said. "They don't care where they run."
Walmart IT uses its cloud platform to make 170,000 adjustments to the website back end alone each month, according to the company. That number is 1,700 times greater than the previous technology.
Having consistency between the three clouds is critical in allowing developers to choose the most cost-effective platform that meets the workload's needs, Evans said. Without that option, Walmart could pay millions more for public cloud services.
Walmart's neutralizing abstraction layer has lowered cloud spending by between 10% and 18%.
The unification of multi-cloud management tackles the complexity of moving data between public clouds and individual applications on private IT environments. An Enterprise Strategy Group (ESG) survey of 372 private and public organizations found that companies used on average a dozen observability tools to manage the integrations between on-premises applications and the cloud.
Walmart leans heavily on APIs when moving data between applications.
"[Multi-cloud integration] has to be built into the applications from an API perspective for this to be successful," ESG analyst Rob Strechay said. "But that brings in many management and observability headaches."
Walmart embraces OpenStack
The retail giant's pursuit of platform choice goes beyond moving workloads. It has also built a network of 10,000 servers running its OpenStack-based cloud infrastructure across distribution facilities and more than 5,500 stores.
"We have one of the largest OpenStack deployments in the world," Evans said.
This year, Walmart broke up its U.S. distributed cloud infrastructure into three regional clouds, the Pacific Northwest and areas around Texas and Virginia. Each triplet lets developers place latency-sensitive workloads as close to the cloud providers' data centers as possible.
That proximity could be as close as the same colocation facility, Evans said. The regional model also provides the capacity for handling store and web traffic bursts during the back-to-school and Christmas shopping seasons.
Walmart found its cloud partners more cooperative than expected. The retailer's size certainly gives it leverage, but Evans encourages smaller enterprises to seek more flexibility from their providers.
Microsoft and Google let Walmart run some of their respective software on any of the three clouds, Evans said. The concessions came after Walmart "applied a little pressure."
"That was something that didn't exist when we started," Evans said. "[Now] they recognize the value proposition is in the software and not necessarily in the infrastructure where you're running it."
Walmart's size demanded a cloud architecture that exceeds that of most enterprises. Nevertheless, designing it to offer a choice of cloud platforms to control cost is possible for any size company.
Enterprise Strategy Group is a division of TechTarget.
Antone Gonsalves is the news director for the Networking Media Group. He has deep and wide experience in tech journalism. Since the mid-1990s, he has worked for UBM's InformationWeek, TechWeb and Computer Reseller News. He has also written for Ziff Davis' PC Week, IDG's CSOonline and IBTMedia's CruxialCIO, and rounded all of that out by covering startups for Bloomberg News. He started his journalism career at United Press International, working as a reporter and editor in California, Texas, Kansas and Florida.