Category: kubernetes

Abstract grid of glowing compute cells densely packed into reserved cluster capacity

Spark on Kubernetes Reserves CPU It Never Uses. Here’s the Overcommit Fix.

Spark sets executor CPU requests equal to limits, so a Kubernetes cluster reserves twice the CPU it uses and refuses to schedule pending pods. Kubernetes has no native overcommit. Here is the mutating-webhook operator I use to fix it.

By jlu, 2 weeks ago

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Choosing the Right Storage Backend for Kubernetes PVCs

Most discussions about PVC focus on on-prem deployments, but many of these technologies are equally relevant in the cloud, especially when using managed block storage like AWS EBS, which caps at around 64K IOPS. By contrast, OpenEBS LocalPV (ZFS or LVM) can attach directly to NVMe-backed local disks, unlocking true Read more

By jlu, 6 months2025-12-15 ago