Microsoft released the public preview of Azure SQL Database Managed Instances – a new option for running SQL Server workloads in the cloud.
Managed Instances (or Azure SQL Database Managed Instances, are a new PaaS database offer that joins the Azure SQL Database and Elastic Pool services. Within this PaaS family, Managed Instances take care of operational aspects like ensuring: high availability, backups, and applying patches, making these simpler and less time-consuming to administer.
While many organizations have benefited from using Azure SQL Database for new applications, it has been a significant challenge to migrate existing workloads because of key functionality gaps versus on-premises SQL Server.
Managed Instances address that problem, by providing vastly improved compatibility. Organizations can therefore more easily migrate existing on-premises SQL Server workloads to the cloud while retaining many of the manageability benefits of a PaaS offering.
Managed Instances require less operational oversight compared to traditional on-premises SQL Server,. Use of the service however, doesn’t free you from the responsibility for checking availability or ensuring that security is configured appropriately. It also remains the DBA’s responsibility to optimize performance, and to handle other operational concerns like making sure jobs complete successfully, or general troubleshooting – its platform as a service. High availability, automated backups, point-in-time restore, automatic plan correction, threat detection, vulnerability assessment, and other intelligent features are built-in into service without any additional charge. OS patching and database upgrades are handled automatically and do not require any action.
In addition to built-in monitoring and maintenance features, you can use any 3rd-party tool to monitor and manage your instance, because most of the system views are exposed.
Connectivity
Azure SQL Managed Instance is not a service on public endpoint. Azure SQL Managed Instance is placed on private IP address in your VNET. It is just hosted and managed by Azure cloud.
Currently, Azure SQL Database PaaS has two main offers for the customers who use SQL Server database and want to migrate to PaaS:
1.Managed Database – isolated and self-contained database service that has database scoped functionalities.
2.Elastic pool – a group of Azure SQL databases that share the same resource.
However, current Azure SQL Database offers don’t provide entire SQL Server “Instance as a Service” as PaaS model. As a result, some of the instance-level features in Azure SQL Database PaaS such as SQL Agent or linked servers are not supported because they are not applicable on the database level.
Currently, the only way to get the full SQL Server instance in Azure is to use Azure SQL VM that handles underlying infrastructure (e.g. disks), but still not have some SQL PaaS features as Azure SQL Database.
Managed Instance is a SQL Server Instance in Azure cloud that shares the same code with the latest version of SQL Server Database Engine and has the latest features, performance improvements, and security patches. It has most of the SQL Server 2017 features (excluding some on-premise Windows features such as Windows logins or potentially harmful features such as extended stored procedures) and enables you to put almost any database that you have in on-premises SQL Server instance. Every instance is fully isolated from the other customer instance and placed in your dedicated subnet with assigned private ip addresses.
Security/Isolation. Managed Instance is a resource in your network hosted by Azure cloud. You have to create Azure VNET and a dedicated subnet where the instance should be deployed. There are networking constraints for the VNET/subnet that you should review before you create a managed instance.
There is no public IP address dedicated to the Managed Instance. Only applications in customer network can access Managed Instance. Network administrators have the full control and can configure access to Managed Instance using standard methods such as Network security Groups and firewalls.
Choose how many CPU cores to use and how much storage you need. You can create a Managed Instance with 16 cores and 500GB storage, and then increase or decrease these numbers depending on your needs. Changing CPU or storage in instance can be done via Azure portal using simple slider.
Managed Instance has split compute and storage components. There are compute nodes with 8, 16, or 24 cores, that work with database files stored on Azure Premium disk storage. Every database file is placed on separate Azure premium disk, that guarantees that database files cannot be lost. Although Managed Instance relies on Azure Premium disks, it also has separate backup mechanism that ensures that even if something would happen with the files, platform would still be able to restore files from backups.
