What are instance pools?

Instance pools are a deployment option in Azure SQL Managed instance service to provision small, cost-effective 2-vCore instances. This way, small instances can cost 50% less compared to non-pooled instances, making it an attractive PaaS target when migrating small on-premises servers or modernizing SQL VMs.

Pooled instance provisioning time is fast and predictable which recommends them for scenarios involving ad-hoc (also: at scale) instance creation or rapid capacity scaling. This allows central IT teams to enforce security and other policies more effectively, as they can provision instance pools in advance, which streamlines the process whenever an application team needs a new instance.

What is new?

Today we are announcing the following new features:

• General availability for instance pools
• Instance pools can now be updated via Azure Portal: configuring compute hardware type, compute size, licensing option, maintenance window, tags
• Reservations for compute vCores are now supported

Earlier this year we introduced the following new functionalities:

• General capabilities:
• Support for Premium Hardware (Gen8)
• Azure Portal:
• Instance pool can be created via Azure Portal
• A single instance (SQL MI) can be created directly into an instance pool via Azure Portal
• PowerShell / Azure CLI client:
• Instance pool can be updated after its creation: changing compute size, license type, hardware type, maintenance window.

A single instance (SQL MI) can be moved in and out of an instance pool via PowerShell and Azure CLI.

Update an instance pool via Azure Portal

Use the Compute + storage pane under Settings of the Instance pool page in the Azure portal to update the license type, vCore size, and hardware type for your pool:

Use the Maintenance pane under Settings of the Instance pool page in the Azure portal to update the maintenance window for your pool:

Purchase reservations for compute vCores

The process of purchasing reservations for instance pool compute vCores is identical as for single SQL Managed Instances:

1. Sign in to the Azure Portal
2. Select All services > Reservations.
3. Select Add and then in the Purchase Reservations pane select SQL Managed Instance
4. Fill in the required fields. Both existing SQL Managed Instances as well as SQL Managed Instance pools that match the attributes you select qualify to get the reserved capacity discount. The actual number managed instances that get the discount depends on the scope and quantity selected.
   
   

Summary

Azure SQL Managed Instance pools enable deploying cost-effective 2-vCore instances, providing an ideal PaaS target for small instances when migrating SQL Servers to Azure or when already running their existing fleet of Azure SQL Managed Instances.

Instance pools also enable fast and predictable ad-hoc instance provisioning, as the complete environment (underlying compute infrastructure, networking, security policies, etc.) is being previously setup while creating the instance pool.

Reference

• What is an instance pool?
• Create instance pools
• Save costs for resources with Azure Reservations - SQL Managed Instance
• Unsupported features and other restrictions
• Resource limits