Subnet sizing for a new workspace

This page includes subnet sizing information for admins deploying new workspaces. The size of your workspace's subnets determines the maximum number of Databricks compute nodes that can run in the workspace at the same time.

Subnet requirements

If you deploy your workspace in a customer-managed VPC, you choose its subnets. Databricks needs at least two subnets for each workspace, each in a different availability zone. For the full list of subnet requirements, see Subnets.

Each subnet must have a netmask between /17 and /26. Databricks assigns two IP addresses to each node, one for management traffic and one for Spark applications, and AWS reserves five IP addresses in each subnet. The maximum number of nodes for each subnet is half of the remaining IP addresses.

Subnet sizes are expressed in CIDR notation.

Quick sizing guideline

Use the following table to estimate the maximum number of Databricks cluster nodes that each subnet can support based on the subnet size.

VPC size (CIDR)	Subnet size (CIDR)	Maximum Databricks cluster nodes per subnet
/16 or a larger network (smaller prefix)	/17	16,381
/20 or a larger network (smaller prefix)	/21	1,021
/25 or a larger network (smaller prefix)	/26	29

VPC size (CIDR)	Subnet size (CIDR)	Maximum Databricks cluster nodes per subnet
/16 or a larger network (smaller prefix)	/17	16,381
/20 or a larger network (smaller prefix)	/21	1,021
/25 or a larger network (smaller prefix)	/26	29