Why Hyperscalers Prefer VMs for Containerized Workloads
This article explores why major cloud providers like AWS, Microsoft, and Google predominantly run containerized workloads on Virtual Machines (VMs) rather than bare metal. It highlights that the performance gap between VMs and bare metal has significantly closed, while VMs offer superior benefits in operational control, isolation, security, and scalability. This architectural choice has crucial implications for enterprise IT teams designing their cloud and hybrid environments.
Read original on DZone MicroservicesThe common perception among many developers is that running containers directly on bare metal provides optimal performance by eliminating virtualization overhead. However, research indicates that major cloud providers (hyperscalers) overwhelmingly deploy containerized workloads on virtual machines, even for their internal operations and customer-facing services. This strategic choice reveals a nuanced understanding of cloud architecture, prioritizing operational benefits over marginal raw performance gains.
The Performance-Complexity Trade-off
Historically, bare metal offered a performance edge. However, modern hypervisors and custom hardware, like AWS Nitro, have drastically minimized this gap. Benchmarks show VMs retaining up to 99% of bare metal performance. The trade-off is that bare metal introduces significant operational complexity, requiring more manual management and lacking the inherent scalability and isolation benefits of virtualized environments. Hyperscalers consistently choose the operational simplicity, isolation, and scalability offered by VMs.
- AWS defaults to virtualization for its control plane and customer workloads, reserving bare metal for highly specialized cases.
- Microsoft Teams and Microsoft 365 rely on VMs for Kubernetes deployments, citing elasticity, straightforward lifecycle management, and simplified day-two operations.
- Google's Borg, a legacy system, runs on bare metal, but almost all other Google services (Gmail, YouTube) and new clusters leverage VMs.
- DigitalOcean exclusively uses VMs for its internal platform and recommends them for customers due to ease of use, maintenance, and predictable operational behavior.
Key Advantages of VMs for Container Orchestration
Why VMs Win for Hyperscalers
VMs provide robust security and isolation boundaries that containers alone do not, crucial for multi-tenancy. They simplify fleet management, provisioning, scaling, and lifecycle management for containerized workloads, making them economically and operationally superior at hyperscale. Fast node recovery and simplified operational models are additional benefits.
For enterprise IT and platform engineering teams, the takeaway is clear: while bare metal has niche uses for extreme performance or specific hardware requirements, virtual machines remain the default and most practical choice for running containerized workloads both on-premises and in the cloud. The operational advantages, coupled with near bare-metal performance, make VMs the superior foundation for robust and scalable cloud architectures.