Leveraging open source for operational excellence

With more than 25,000 engineers developing and overseeing solutions for more than 10,500 stores and thousands of fulfillment centers (FCs) and distribution centers (DCs), over 5 million devices connected to our network at any time, and more than 2.1 million associates globally, the scale of Walmart is unmatched, as is the demand on its network.  

When you consider that each associate carries either a phone, a laptop, or both that connects to our network whenever they’re in a store or office, and then consider all the other devices and solutions connecting to our network that handle transactions and the inventory in our stores and clubs, from robots to point of sale systems, the depth of operations is immense. We also manage the Walmart.com site and mobile app, which along with our stores, enable us to serve more than 255 million customers and members per week.

Our infrastructure comprises more than 100,000 routers and switches—75% of which are PoE enabled, in addition to over 700,000 PE ports, 450,000 wireless access points, and more than 10,000 edge nodes that store and communicate all the data we generate across the span of our network.

Evolving our infrastructure to meet the scale

Large networks bring unique challenges. At the scale and speed at which we operate, there are finite vendor software packages that can run everything and having a variety of vendor solutions with different platforms, features and requirements isn’t ideal.

Instead, we’ve built our operations organically over time, partnering with the open source community. This approach has given us the capability to consolidate our code base, removed the risk of concerns regarding feature parity, bugs and security, and maintained lower operational costs.

Why open source?

Open-source technologies allow us to define a new path for operational excellence. The collaborations enable teams to innovate faster, and we’ve seen incredible results in terms of reliability and reduced engineering cognitive load.

It is also consistent with our focus on EDLC, or every day low costs; every dollar that we save on operations and our network saves our customers money. 

Two projects we’re seeing great results from are SONiC and L3AF.

How we’re using open source

SONiC (Software for Open Networking in Cloud) is an open-source network operating system based on Linux that enables us to deploy whitebox hardware from multiple vendors, while running a common network operating system (NOS) on all the switches.

In an environment like ours, having engineers logging into systems and running things throughout the day is risky and doesn't scale when deploying to thousands of stores and hundreds of thousands of network elements. Automation is key for providing visibility across the entire environment and parity across services, as well as deploying change across devices, NOS, and hardware platforms.

We’ve been deploying SONiC at scale in our data centers for several years and are working toward expanding its use beyond data centers, putting it in our stores, FCs, DCs, and campuses. 

L3AF is an orchestration platform for eBPF based programs that provides networking and observability solutions and lifecycle management. Given our scale, we need to be able to run multiple programs simultaneously. L3Af provides us with the capability to monitor, inspect and control our systems. This includes visualizing our site traffic, so we understand its direction and functionality, so we can prioritize within the network. Further, the capabilities to accelerate site speed and debug the network means better experiences and leads to value vision and ROI.

What’s next?

We see a lot of potential in open source and are seeing sustained business impact connected to these projects. They have been pivotal, driving significant transformations and advancements within our organization. We believe in the power of open source and its potential to revolutionize the way we work.

We are deeply committed to making sure these open source communities—and others—continue to grow and flourish and want to hire more talent for development and community contribution. 

Interested in growing with us? Check out our career page and stay tuned for more announcements from us in this space!