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At my current employer, we use Kubernetes to run hundreds of thousands of bare metal servers, spread over hundreds of Kubernetes clusters. We use Kubernetes beyond officially supported/tested scale limits by running more than 5,000 nodes and over a hundred thousand of pods in a single cluster. 1 In these large scale setups, expensive “list” calls on the Kubernetes API are the achilles…
We presented our LinkedIn compute infrastructure team’s journey moving LinkedIn’s large 500,000+ bare metal servers running thousands of microservices and a lot of stateful workloads to a Kubernetes based platform. In this session, we talk about LinkedIn’s scale, how we automate bare metal server management and maintenance from the ground up, built Kubernetes node and cluster…
Ronak and I were Abdel’s guests at the Kubernetes Podcast by Google ahead of our KubeCon talk in London next month. We talked about our work building the next generation of the compute infrastructure at LinkedIn with Kubernetes, the challenges we faced and our journey dealing with the scale and complexity so far.
Anyone who is running Kubernetes in a large-scale production setting cares about having a predictable Pod lifecycle. Having unknown actors that can terminate your Pods is a scary thought, especially when you’re running stateful workloads or care about availability in general. There are so many ways Kubernetes terminates workloads, each with a non-trivial (and not always predictable) machinery, and…
Any company using Kubernetes eventually starts looking into developing their custom controllers. After all, what’s not to like about being able to provision resources with declarative configuration: Control loops are fun, and Kubebuilder makes it extremely easy to get started with writing Kubernetes controllers. Next thing you know, customers in production are relying on the buggy controller…
Last week, OpenAI has suffered a several hours long outage and published a detailed postmortem about it. Highly recommend reading it. These technical reports are usually a gold mine for all large-scale Kubernetes users, as we all go through similar set of reliability issues running Kubernetes in production.
This is the analysis of a low severity incident that took place in the Kubernetes clusters at the company I work at that taught me a lot about how to think about the off-the-shelf components we bring from the ecosystem into the critical path and operate at a scale much larger than these components are intended.
A quick code search query reveals at least 7,000 Kubernetes Custom Resource Definitions in the open source corpus, 1 most of which are likely generated with controller-gen —a tool that turns Go structs with comments-based markers into Kubernetes CRD manifests, which end up being custom APIs served by the Kubernetes API server. At LinkedIn, we develop our fair share of custom Kubernetes APIs and…
I’ve recently done a Twitter poll and only 20% of the participants accurately predicted that it takes Kubernetes 60-90 seconds to propagate changes to Secrets and ConfigMaps on the mounted volumes. So I want to take you on a journey in the codebase on how the mechanics of these volume types work and why it takes so long. Before going on this journey, I would answer the poll “nearly…
Files on Kubernetes Secret and ConfigMap volumes work in peculiar and undocumented ways when it comes to watching changes to these files with the inotify(7) syscall . Your typical file watch that works outside Kubernetes might not work as you expect when you run the same progam on Kubernetes. On a normal filesystem, you start a watch on a file on disk with a library and expect to get an event like…