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Ray on EKS Deep Dive

Supported Versions: Ray 2.57.0, KubeRay v1.6.1 Last Updated: August 20, 2026

Overview

Ray is an open-source distributed computing framework for scaling Python workloads — from ad hoc parallel tasks to distributed training, hyperparameter tuning, and model serving — built around a small set of core primitives (tasks, actors, and a shared object store) rather than a separate tool per workload type. On Kubernetes, the KubeRay operator translates a Ray cluster's head/worker-node shape into native Kubernetes resources, making Ray clusters declarative and giving EKS the same deployment and autoscaling story it already uses for other workloads.

Component Map

ConceptProblem It SolvesDeep Dive
ArchitectureTasks, actors, and the object store that everything else builds onPart 1
KubeRay OperatorRun Ray clusters as native Kubernetes resources (RayCluster/RayJob/RayService)Part 2
Ray Train & TuneDistributed model training and hyperparameter searchPart 3
Ray ServeModel serving, including dedicated LLM-serving building blocksPart 4

The KubeRay Operator sits between Ray's core architecture and two downstream capabilities it unlocks on Kubernetes: distributed training and tuning with Ray Train and Tune, and model or LLM serving with Ray Serve.

Why Run This on EKS

The trade-off is the same one covered elsewhere in this documentation site's data/ML sections: a team already running EKS can reuse the same node-pool autoscaling (via Karpenter), IAM, and observability patterns for Ray workloads as for everything else on the cluster, in exchange for operating the KubeRay operator and its RayCluster/RayJob/RayService resources directly rather than using a managed alternative.

Currently Covered

  1. Part 1: Ray Architecture — tasks, actors, the object store, and the head/worker cluster model
  2. Part 2: The KubeRay Operator — RayCluster, RayJob, RayService, and the two-tier autoscaling pattern with Karpenter
  3. Part 3: Ray Train and Ray Tune — distributed training and hyperparameter tuning
  4. Part 4: Ray Serve — model serving, Ray Serve LLM, and RayService-based production deployment