Creating a GeminiDB Cassandra Instance¶
This section describes how to create a DB instance that is compatible with Cassandra APIs.
Procedure¶
On the Instances page, click Create DB Instance.
On the displayed page, select your DB instance specifications and click Create Now.
Table 1 Basic information¶ Parameter
Description
Region
The region where the tenant is located.
ImportantNOTICE: Select the region nearest where you will be accessing the DB from so latency can be kept to a minimum and response time will be faster. Also, products deployed in different regions cannot communicate with each other through a private network and you cannot change the region of an instance after creating the instance.
DB Instance Name
The new name can be the same as an existing instance name. It must start with a letter and consist of 4 to 64 characters. Only letters (case-sensitive), digits, hyphens (-), and underscores (_) are allowed.
After the DB instance is created, you can change the DB instance name. For details, see section Changing a DB Instance Name.
Compatible API
Cassandra
DB Instance Type
Cluster
DB Engine Version
3.11
AZ
An AZ is a part of a region with its own independent power supplies and networks. AZs are physically isolated but can communicate through an internal network connection.
Table 2 Specifications and storage¶ Parameter
Description
Instance Specifications
The CPU and memory of a DB instance.
Performance specifications vary depending on the connections and maximum IOPS.
After a DB instance is created, you can change its CPU and memory. For details, see Changing the CPU and Memory of an Instance.
Nodes
The number of nodes ranges from 3 to 200. Select the number of nodes based on the site requirements.
After a DB instance is created, you can add nodes. For details, see Adding Nodes.
Storage Space
Storage space depends on the instance specifications. The minimum storage space is 10 GB, and the storage space you set must be an integer. You can select a minimum of 10 GB each time.
After a DB instance is created, you can scale up its storage space. For details, see Scaling Up Storage Space.
When configuring storage space of a GeminiDB Cassandra instance, you are advised to enable autoscaling. Then set trigger conditions and limit of autoscaling. After autoscaling is triggered, the system automatically scales up the storage to ensure that the instance has sufficient storage and keeps available.
Figure 1 Auto Scale¶
Pay attention to the following parameters:
Trigger If Available Storage Drops To: storage threshold for triggering autoscaling. When the available storage usage drops to this value or the available storage space drops to 10 GB, autoscaling is triggered.
Increase By: percentage that your instance storage will be scaled up at. If the increased storage is not a multiple of 10 GB, the system will round it up to the nearest multiple of 10 GB. At least 100 GB is added each time.
Storage Limit: maximum amount that the system can automatically scale up an instance's storage space to. The value must be no less than the current storage of your instance and cannot exceed the storage space upper limit defined by your instance specifications.
NoteOnce autoscaling is enabled, an agency will be created and fees will be automatically deducted.
You can enable autoscaling after an instance is created. For details, see Configuring Auto Scale.
Table 3 Network¶ Parameter
Description
VPC
The virtual network where your DB instances are located. A VPC isolates networks for different services. You can select an existing VPC or create a VPC.
If no VPC is available, the system creates one for you.
For details on how to create a subnet, see the "Creating a VPC" section in the Virtual Private Cloud User Guide.
NoteAfter the GeminiDB Cassandra instance is created, the VPC where the instance resides cannot be changed.
Subnet
A subnet provides dedicated network resources that are logically isolated from other networks for network security.
Security Group
A security group controls access between GeminiDB instances and other services. When you select a security group, you must ensure that it allows the client to access DB instances.
If no security group is available, the system creates one for you.
Table 4 Database configuration¶ Parameter
Description
Administrator
The default administrator account is rwuser.
Administrator Password
Set a password for the administrator. The password:
Must be 8 to 32 characters long.
Must contain uppercase letters, lowercase letters, digits, and any of the following special characters:
~!@#%^*-_=+?For security reasons, you must select a strong password. The system will verify the password strength.
Keep this password secure. If you lose it, the system cannot retrieve it.
Confirm Password
Enter the administrator password again.
Parameter Template
A parameter template contains engine configuration values that can be applied to one or more instances.
After a DB instance is created, you can modify parameters to better meet your service requirements. For details, see Modifying a Parameter Template.
Table 5 Tags¶ Parameter
Description
Tags
The setting is optional. Adding tags helps you better identify and manage your DB instances. Up to 20 tags can be added for each instance.
A tag is composed of a key-value pair.
Key: Mandatory if the DB instance is going to be tagged
Each tag key is unique for each instance. The key can include up to 36 characters, including digits, letters, underscores (_), and hyphens (-).
Value: Optional if the DB instance is going to be tagged
The value can contain up to 43 characters, including digits, letters, underscores (_), periods (.), and hyphens (-).
After a DB instance is created, you can view its tag details on the Tags tab. In addition, you can add, modify, and delete tags for existing DB instances. For details, see Managing Tags.
On the displayed page, confirm the DB instance details.
If you need to modify the specifications, click Previous to return to the previous page.
If you do not need to modify the specifications, click Submit to start creating the instance.
On the Instances page, view and manage your DB instances.
Creating a DB instance takes about 5 to 9 minutes. During the process, the instance status displayed in the DB instance list is Creating.
After the creation is complete, the status changes to Available.
You can click
in the upper right corner of the page to refresh the DB instance statuses.During creation, an automated backup policy is enabled by default. A full backup is automatically triggered after a DB instance is created.