This post shows how to deploy one large language model (LLM) across two GPU nodes on Amazon Elastic Kubernetes Service (Amazon EKS) with the multi-node Ray LLM Deep Learning Containers. It uses separate prefill and decode nodes behind one OpenAI-compatible endpoint. This kind of multi-node setup is common for tensor, pipeline, and data parallelism, as well as prefill/decode disaggregation inference workloads. In a previous post, we introduced the Ray Serve DLC and used it to stand up a small model behind an HTTP endpoint on a single GPU node. You had a working inference endpoint, and the container keeps the GPU stack compatible, including CUDA libraries, so you did not need to write boilerplate code.

Ray is a distributed compute framework, so Ray Serve deployments can span multiple nodes. Customers use multi-node Ray Serve for several reasons. Some want to run foundation or open-weight models that are too large for a single GPU. Others need more throughput than one replica can deliver. Still others want to separate the two phases of inference to improve performance. In each case, customers must build the dependency chain themselves: choosing compatible libraries for the GPU stack and debugging issues when a component drifts out of alignment. This is undifferentiated work that takes time and effort away from delivering models.