Kubernetes 1.31 Brings More Stability to Cloud-Native Deployments

The 1.31 version of the open source Kubernetes cloud-native project, code-named "Elli," is now available, providing users of the cloud-native technology with new updates and features.

Kubernetes is the flagship technology of the Cloud Native Computing Foundation (CNCF), which itself is part of the Linux Foundation. Kubernetes at its core is a container orchestration system, and in recent years it has become the de facto standard for enabling hybrid cloud computing. There are multiple ways organizations run Kubernetes on-premises, and every major cloud provider has its own Kubernetes cloud service.

Beyond the widespread deployment options for Kubernetes is the breadth of contributions from multiple vendors: 113 different companies and 528 individuals contributed to the Kubernetes 1.31 release.

The reason Elli was chosen as the code-name for version 1.31? "Elli is a cute and joyful dog, with a heart of gold and a nice sailor's cap, as a playful wink to the huge and diverse family of Kubernetes contributors," claims the Kubernetes v1.31 Release Team.

New features in Kubernetes 1.31 include stable support for the AppArmor security technology, as well as improved networking and storage capabilities.

"1.31 is addition through subtraction," Peter Smails, general manager of enterprise container management at SUSE, told ITPro Today. "Instead of encompassing everything flashy — often destabilizing — this release is business as usual, concentrating on delivering a tight and reliable core, a move enterprise customers are sure to appreciate."

Related:How to Simplify Kubernetes Management

Why Ingress Connectivity Matters for Cloud-Native

Among the stable updates that have landed in Kubernetes 1.31 is a networking improvement that could make a big difference for operators.

All Kubernetes features are first defined in a Kubernetes Enhancement Proposal (KEP), which gives details about the change. KEP-3836 defines a Kube-proxy improvement for ingress connectivity reliability. The Kube-proxy system is a network proxy that helps maintain connectivity across running services.

"This feature is great because users and operators do not have to do anything themselves. They can still deploy the same resources and keep using Kubernetes the same way they did," Angelos Kolaitis, release lead for Kubernetes 1.31, told ITPro Today. "But we see a great behind-the-scenes effort in making the core of Kubernetes much more stable and reliable, such that people and companies know that they can trust it to run their critical workloads."

Cloud-Native Storage and Memory Get a Boost

Related:How to Fix OOMKilled Errors in Kubernetes

Storage is another critical area of cloud-native operations that gets a boost in the Kubernetes 1.31 update.

With containers and cloud-native, a common concern in the past was about ephemeral resources — that is, resources that are not persistent and are not always present.

With KEP-3762, there is an update for persistent volumes of storage, helping to ensure that operators are aware of storage asset status. The new PersistentVolumeStatus field now provides a timestamp of when a PersistentVolume was changed to a different phase of operation.

Another core area of improvement is enhanced swap memory support. Swap memory is a foundational type of memory used in a Linux system and, until version 1.31 support, was not present in Kubernetes.

"Kubernetes currently does not support the use of swap memory on Linux, as it is difficult to provide guarantees and account for pod memory utilization when swap is involved," KEP-2400 states. "This proposal aims to add swap support to nodes in a controlled, predictable manner so that Kubernetes users can perform testing and provide data to continue building cluster capabilities on top of swap."

Elli, the code name for Kubernetes 1.31, is a nod to Kubernetes' vast and diverse contributor community.

Alpha Features in Elli Release Show the Future Promise of Kubernetes

Kubernetes updates aren't just about stable releases. Each release also introduces new features as alphas, which are matured and developed over subsequent Kubernetes updates.

Among the noteworthy preview features in Kubernetes 1.31 are ones that could help with artificial intelligence (AI) workloads as well as provide new support for image volumes.

The Dynamic Resource Allocation with Control Plane Controller alpha feature is particularly interesting, according to Kolaitis. He said many in the Kubernetes community consider this feature to be the future, or at least the path toward making hardware accelerators available to workloads running in a Kubernetes cluster. 

The other alpha feature Kolaitis highlighted is VolumeSource: OCI Artifact and/or Image. This feature, he explained, is aimed at making it easy to use an OCI container image as a volume source for Kubernetes workloads. 

"This allows reusing the well-defined and well-known process of building an OCI image for managing external binaries, resources — for example, machine learning model weights or configurations that should not be built into the main workload image," he said.

How the Kubernetes Release Process Keeps Getting Better

The Kubernetes platform is widely used. In fact, the CNCF's latest annual survey claims that 84% of organizations are either using or evaluating Kubernetes in some way.

The core Kubernetes project gets multiple milestone releases in any given year. Given the volume of participation and how widely deployed the technology is, it's no easy task to keep new updates coming either.

"Kubernetes is a huge open-source project, and cutting a new minor release involves a lot of coordination and numerous activities," Kolaitis said.

Kolaitis noted that there is a lot of documentation and processes that have already been established for Kubernetes releases, but it's a process that is always being improved.

"Recent releases have seen the introduction of tooling that automates steps which were performed manually in the past," he said. "And we also see constant iterations on the process itself, consolidations of the release steps, and even the make-up of the team itself."