Creating SQL Server clusters
A SQL Server cluster is one or more database hosts that replication can be configured between. Replication is enabled by default in any cluster consisting of more than one host: the master host accepts write requests, synchronously duplicates changes in the primary replica, and does it asynchronously in all the others.
If database storage is 95% full, the cluster switches to read-only mode. Plan and increase the required storage size in advance.
How to create a SQL Server cluster
In the management console, select the folder where you want to create a database cluster.
Select Managed Service for SQL Server.
Click Create cluster.
Enter the cluster name in the Cluster name field. The cluster name must be unique within the folder.
Select the environment where you want to create the cluster (you can't change the environment once the cluster is created):
PRODUCTION: For stable versions of your apps.
PRESTABLE: For testing, including the Managed Service for SQL Server service itself. The Prestable environment is first updated with new features, improvements, and bug fixes. However, not every update ensures backward compatibility.
Select the DBMS version. Currently, we support
2016 ServicePack 2of the following editions:
- Standard Edition.
- Enterprise Edition.
For more information, see Relationship between service resources.
Select the host class to define the technical specifications of the VMs where the database hosts will be deployed. All available options are listed in Host classes. When you change the host class for the cluster, the characteristics of all existing hosts change, too.
Under Storage size:
- Select the type of storage, either more flexible network storage (network-hdd or network-ssd) or faster local SSD storage (local-ssd). The size of local storage can only be changed in 100 GB increments.
- Select the size to be used for data and backups. For more information about how backups take up storage space, see Backups.
Under Database, specify the database attributes:
- Database name. This name must be unique within the folder and contain only Latin letters, numbers, and underscores.
- Username of the database owner. This name may only contain Latin letters, numbers, and underscores. By default, the new user is assigned 50 connections to each host in the cluster.
- User password (from 8 to 128 characters).
Under Hosts, select the parameters for the database hosts created with the cluster. You can add either one, three, or more hosts. By default, each host is created in a separate subnet. To select a specific subnet for the host, click in the row of the host and select the desired availability zone and subnet.
- If you select Standard Edition, you can create a cluster from only one host. This cluster does not provide any fault tolerance. For more information, see Relationship between service resources.
- At the moment, you can create an Enterprise Edition cluster with either one or three hosts.
Click Create cluster.
To create a cluster, use the create API method and pass the following in the request:
- In the
folderIdparameter, the ID of the folder where the cluster should be placed.
- The cluster name, in the
- Cluster configuration, in the
- Configuration of the cluster hosts, in one or more
- Cluster database configuration, in one or more
- Configuration of the accounts in the cluster database, in one or more
- Network ID, in the