Configuring Auto Scale

You can enable Auto Scale for GeminiDB Cassandra instances. When storage space usage reaches the upper limit, autoscaling is triggered.

You can enable Auto Scale:

When you create an instance. For details, see Buying an Instance.
After you create an instance

This section describes how to configure Auto Scale after an instance is created.

If you enable Auto Scale using a Huawei Cloud account, no additional configuration is required.
If you enable Auto Scale as an IAM user first time, you need to obtain the permission to create an agency.

Configuring Permissions

If you are using an IAM user, perform the following operations to configure GeminiDB and IAM permissions before enabling Auto Scale:

Configure the GeminiDB FullAccess permission.

Configure fine-grained permissions for IAM.

For details about how to configure IAM permissions, see Creating a Custom Policy.

If you use the JSON view to configure a custom policy, the policy content is as follows:

{
     "Version":"1.1",
     "Statement":[
         {
             "Effect":"Allow",
             "Action":[
                 "iam:permissions:listRolesForAgencyOnProject",
                 "iam:permissions:grantRoleToGroupOnProject",
                 "iam:agencies:createAgency",
                 "iam:agencies:listAgencies",
                 "iam:roles:listRoles",
                 "iam:roles:createRole"
             ]
         }
     ]
}

Create a user group and assign permissions.
You can create a user group on the IAM console and grant it custom permissions created in 2 and the security administrator role.
Create an IAM user and add it to a user group.
Log in to the IAM console using a Huawei Cloud account or as an IAM user, locate the IAM user that the target instance belongs to, and add it to the user group created in 3. The IAM user will inherit permissions of the user group.

Precautions

Auto Scale is available only when your account balance is sufficient.
Autoscaling is currently in open beta testing. If you need to use this function, contact customer service to apply for it.
The instance is in the Available status.
Once Auto Scale is enabled, an agency will be created and fees will be automatically deducted.

Automatically Scaling Up Storage of a Single Instance

Log in to the GeminiDB console.
In the service list, choose Databases > GeminiDB Cassandra API.
On the Instances page, click the instance. The Basic Information page is displayed.
In the Storage Space area, click Auto Scale.

Figure 1 Auto Scale

Toggle on Auto Scale and specify the parameters below.

Figure 2 Configuring Auto Scale

**Table 1** Description
Parameter	Description
Auto Scale	If you toggle on this switch, autoscaling is enabled.
Trigger If Available Storage Drops To	When the available storage usage drops to a specified threshold or the available storage drops to 10 GB, autoscaling is triggered.
Increase By	Percentage of the current storage to be automatically scaled. The value can be 10, 15, or 20. At least 100 GB is added each time.
Storage Limit	Upper limit of the storage space in GB that can be automatically scaled to The limit must be no less than the storage of your instance and cannot exceed the maximum storage space defined by your instance specifications.

Click OK.

Automatically Scaling Up Storage of Multiple Instances In Batches

Log in to the GeminiDB console.
In the service list, choose Databases > GeminiDB Cassandra API.
Select instances and click Auto Scale.

Figure 3 Auto Scale

Select an instance, toggle on Auto Scale, and specify the parameters below.

Figure 4 Batch Auto Scale

**Table 2** Description
Parameter	Description
Auto Scale	If you toggle on this switch, autoscaling is enabled.
Trigger If Available Storage Drops To	When the available storage usage drops to a specified threshold or the available storage drops to 10 GB, autoscaling is triggered.
Increase By	Percentage of the current storage to be automatically scaled. The value can be 10, 15, or 20. At least 100 GB is added each time.
Storage Limit	This parameter cannot be customized. By default, the storage is scaled up the maximum of the selected instance.