The r5n.8xlarge is a memory-optimized AWS EC2 instance: 32 vCPU and 256 GiB of memory, 8.00 GiB per vCPU. In the name, "r" stands for RAM, "5" is the generation, "n" marks enhanced networking and "8xlarge" is the size within the r5n family. It runs on Intel Xeon Platinum 8259 (Cascade Lake) at 2.5 GHz, and AWS introduced it in October 2019. AWS has since shipped r6i, r7i, r8i and r9g; r6i.8xlarge is the direct replacement at this size, scoring 547,219 CoreMark/s against this instance's 448,514 — roughly 22% more throughput for the same vCPU count. No single Spot node covers 32 vCPU and 256 GiB, so the equivalent is a fleet: 2 × mh.vs1.2xlarge, 32 vCPU and 256 GiB in total, $2.38/hr on AWS in US East (N. Virginia), from $0.042/hr on Rackspace Spot. Spot delivers compute as managed Kubernetes, so a node pool of that size is the native shape of the answer rather than a workaround — provided the workload scales horizontally.
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r5n.8xlarge gives you 32 vCPU and 256 GiB in a single machine. The largest comparable Spot node, mh.vs1.2xlarge, is 16 vCPU and 128 GiB, so the equivalent here is 2 nodes rather than one.
Spot runs as managed Kubernetes, so a 2-node pool is the normal way to run things rather than a workaround. If your workload already sits behind a load balancer, a queue or a scheduler, it spreads across them without changes. If it needs all 32 cores and 256 GiB in one process, it does not.
