AWS Dedicated Hosts: Your Own Physical Server in the Cloud

Why it exists

Standard cloud computing is multi-tenant, which creates two problems. First, some expensive software licenses are tied to physical hardware like cores or sockets, making them incompatible with shared servers. Second, certain industries have strict compliance rules requiring physical workload isolation. Dedicated Hosts solve both.

The mental model

A Dedicated Host is like renting an entire apartment building instead of just one apartment. You get exclusive use of the building, can bring your own specific furniture (software licenses), and meet privacy rules (compliance). You have control over which rooms (instances) are used, but you pay rent on the whole building, even the empty rooms.

How it works

You provision a physical server from AWS that is not shared with any other customer. You then launch EC2 instances onto this host. AWS License Manager integrates with Dedicated Hosts to help track your software licenses against the host's physical cores and sockets. You gain visibility into the underlying hardware and can control instance placement with affinity rules. AWS still manages the physical hardware maintenance, automatically migrating your instances to a new host if the original one fails.

When to use it

Use Dedicated Hosts for two main reasons. First, when you need to use existing per-socket or per-core software licenses in the cloud, a strategy called "Bring Your Own License" (BYOL). This is common for Oracle or Microsoft software. Second, when you must meet corporate compliance or regulatory requirements that explicitly forbid running workloads on multi-tenant hardware.

When not to use it

Avoid Dedicated Hosts for general-purpose workloads. Standard, multi-tenant EC2 instances are far more cost-effective as you only pay for the capacity you use. If you only need instance-level isolation but not a whole server for licensing, EC2 Dedicated Instances can be a simpler alternative, though they lack the hardware visibility of Dedicated Hosts.

One canonical example

A financial services company needs to migrate an on-premises database running Microsoft SQL Server Enterprise Edition, licensed per-core. To remain compliant with their license terms in the cloud, they provision an EC2 Dedicated Host. They can see the exact number of physical cores, assign their SQL Server licenses accordingly using AWS License Manager, and launch their database instance onto that specific host, ensuring both license compliance and single-tenancy.