Azure SQL Managed Instance

Azure SQL Managed Instance is a deployment option of Azure SQL Database that provides a fully managed Platform as a Service (PaaS) solution while maintaining compatibility with on-premises SQL Server environments. It operates on a VCore-based purchasing model.

Advantages of Using Managed Instance

1. Easy Lift and Shift:
   • Facilitates the migration of on-premises SQL Server databases to Azure with minimal changes required for applications.
   • Ensures compatibility with existing SQL Server features, making the transition smoother.
2. Fully Managed PaaS:
   • Ideal for businesses looking to migrate multiple applications from self-hosted environments or Independent Software Vendor (ISV) solutions to a fully managed cloud environment.
   • Reduces the burden of infrastructure management and allows focus on application development.
3. New Business Model:
   • Offers a competitive, transparent, and frictionless pricing structure, allowing businesses to better predict costs.
4. Security:
   • Provides enhanced security features, including complete isolation of customer instances through native Virtual Network (VNet) support.
   • Designed to meet high-security standards while ensuring compatibility with on-premises SQL Server.

Managed Instance Security Isolation

Azure SQL Managed Instance includes several layers of security isolation to protect customer data:

• Native Virtual Network Implementation:
  • Allows secure connectivity to on-premises environments through Azure ExpressRoute or VPN Gateway.
• Private SQL Endpoint:
  • The SQL endpoint is exposed only through a private IP address, ensuring safe connections from private Azure networks or hybrid networks.
• Single-Tenant Environment:
  • Operates in a dedicated environment with its own compute and storage resources, reducing the risk of data exposure to other tenants.

Structure of Managed Instance

When you create an Azure SQL Managed Instance, the following components are established within a virtual network:

• Virtual Network:
  • Includes multiple subnets: Frontend subnet, Gateway subnet, and Managed Instance subnet.
• Node Deployment:
  • Each node consists of the SQL engine and SQL management components and is deployed within the Managed Instance subnet.
  • Multiple nodes can be deployed in the same virtual network, forming a virtual cluster.

Endpoints

The virtual cluster created for the Managed Instance has two primary endpoints:

1. Client Connection Endpoint:
   • This endpoint is used by applications and clients to connect to the Managed Instance.
2. Management Endpoint:
   • A public endpoint used by Microsoft for management purposes, ensuring that automated scripts and maintenance tasks can be performed.

Connectivity Requirements

To ensure the Managed Instance operates correctly:

• Azure Storage and Service Bus Connectivity:
  • It’s essential to allow traffic to Azure Storage and Service Bus to enable proper functioning of the Managed Instance.
• Client Applications:
  • Applications (web apps, virtual machines) can reside in the Frontend subnet or a peered network, allowing for seamless communication with the Managed Instance.
  • On-premises applications can connect to the Managed Instance through a virtual network gateway or ExpressRoute.

All connections to the database are conducted over a private connection, ensuring security and performance.