Buying an Instance

Prerequisites

• You have created a Huawei Cloud account.

Procedure

1. Log in to the GeminiDB console.
2. In the service list, choose Databases > GeminiDB.
3. On the Instances page, click Buy DB Instance.
4. On the displayed page, specify instance specifications and click Next.
   Figure 1 Billing mode and basic information
   

   Table 1 Billing parameters

   Parameter

   Description

   Billing Mode

   Method that the instance is billed in. The value can be Yearly/Monthly or Pay-per-use. Yearly/Monthly In this mode, specify Required Duration at the bottom of the page. The system deducts the fees incurred from your account based on the service price. If you do not need such an instance any longer after it expires, change the billing mode to pay-per-use to optimize costs. For details, see Changing the Billing Mode from Yearly/Monthly to Pay-per-Use. NOTE: Yearly/Monthly instances cannot be deleted directly. If such an instance is no longer required, unsubscribe from it. For details, see Unsubscribing from a Yearly/Monthly Instance. Pay-per-use If you select this billing mode, you are billed based on how much time the instance is in use. If you expect to use an instance for a long period of time, change its billing mode to yearly/monthly to optimize costs. For details, see Changing the Billing Mode from Pay-per-Use to Yearly/Monthly.

   Table 2 Basic information

   Parameter	Description
   Region	Region where a tenant is located NOTICE: Select the region nearest where you will access the instance from so that latency can be kept to a minimum and response is faster. Instances deployed in different regions cannot communicate with each other over a private network. After you buy an instance, you cannot change its region.
   DB Instance Name	The instance name: Can be the same as an existing instance name. Contains 4 to 64 characters and must start with a letter. It is case-sensitive and allows only letters, digits, hyphens (-), and underscores (_). If the name contains Chinese characters, the length cannot exceed 64 bytes. After an instance is created, you can change its name. For details, see Changing an Instance Name.
   Compatible API	Cassandra
   DB Instance Type	Cluster
   DB Engine Version	3.11
   AZ	Availability zone where the instance is created. 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.

   Figure 2 Specifications and storage
   
   Figure 3 Specifications and storage
   

   Table 3 Specifications and storage

   Parameter	Description
   Instance Specifications	Decoupled storage and compute and software-hardware synergy deliver twice or more the performance of an on-premises database with the same specifications. When you create an instance, select higher specification and specify as few nodes as possible. For example, if you need 8 vCPUs, 32 GB, and 6 nodes for an on-premises deployment, then for a GeminiDB Cassandra instance with 8 vCPUs and 32 GB of memory, you only need 3 nodes. Select appropriate specifications based on the CPU-memory ratio. After an instance is created, you can change its specifications. For details, see Changing vCPUs and Memory of an Instance.
   Nodes	Number of nodes that the instance is deployed on. After an instance is created, you can add nodes. For details, see Adding Nodes.
   Storage Space	Instance storage space. The range depends on the instance specifications. For details, see Instance Specifications. Select at least 1 GB each time you scale up the storage, and ensure that the increment is an integer. Enabling autoscaling is recommended. Then set trigger conditions and autoscaling limit. After autoscaling is triggered, the system automatically scales up the storage to ensure that the instance has sufficient storage and keeps available. Trigger If Available Storage Drops To: storage threshold for triggering autoscaling. When the available storage usage drops to a specified threshold or the available storage drops to 10 GB, autoscaling is triggered. Increase by: The 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. Autoscaling Limit: Maximum amount that the system can automatically scale up an instance's storage space to. The value must be no less than the total storage of the instance and cannot exceed its maximum storage. After an instance is created, you can scale up its storage if necessary. For details, see Scaling Up Storage Space. NOTE: Once autoscaling is enabled, an agency will be created and fees will be automatically deducted from your account. Autoscaling is available only when you have the required permission. To enable this function, contact customer service. You can enable autoscaling after an instance is created. For details, see Configuring Auto Scale.

   Figure 4 Network configurations
   

   Table 4 Network configuration

   Parameter	Description
   VPC	Virtual private 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 there are no VPCs available, the system automatically allocates a VPC to you. For details, see "Creating a VPC" in the Virtual Private Cloud User Guide. NOTE: After a GeminiDB Cassandra instance is created, its VPC cannot be changed. If you want to connect to a GeminiDB Influx instance using an ECS over a private network, the GeminiDB Influx instance and the ECS must be in the same VPC. If they are not, you can create a VPC peering connection between them.
   Subnet	A subnet where your instance is created. The subnet provides dedicated and isolated networks, improving network security. NOTE: Create an IPv4 subnet or select an existing one. IPv6 subnets are not supported.
   Security Group	A security group controls access between your instance and other services. Ensure that the security group you selected allows your client to access the instance. If no security group is available, the system creates one for you.

   Figure 5 Database configuration
   

   Table 5 Database configuration

   Parameter	Description
   Administrator	Username of the administrator account. The default value is rwuser.
   Administrator Password	Password of the administrator account. The password: Can include 8 to 32 characters. Can include uppercase letters, lowercase letters, digits, and any of the following special characters: ~!@#%^*-_=+? For security reasons, set a strong password. The system will verify the password strength. Keep your password secure. The system cannot retrieve it if it is lost.
   Confirm Password	This password must be consistent with administrator password.
   Parameter Template	A template of parameters for creating an instance. The template contains API configuration values that are applied to one or more instances. After an instance is created, you can modify its parameters for optimal performance. For details, see Modifying Parameters of GeminiDB Cassandra Instances.
   Enterprise Project	This parameter is provided for enterprise users. An enterprise project groups cloud resources, so you can manage resources and members by project. The default project is default. Select an enterprise project from the drop-down list. For more information about enterprise projects, see Enterprise Management User Guide.

   Figure 6 Tag configuration
   

   Table 6 Tags

   Parameter

   Description

   Tags

   This setting is optional. Adding tags helps you better identify and manage your GeminiDB Cassandra instances. Each instance can have up to 20 tags by default. A tag consists of a tag key and a tag value. Tag key: mandatory if the instance is going to be tagged Each tag key is unique for each instance. It can include up to 36 characters, including digits, letters, underscores (_), and hyphens (-). Tag value: optional if the instance is going to be tagged The value can contain up to 43 characters, including digits, letters, underscores (_), periods (.), and hyphens (-). After an instance is created, you can view its tag details on the Tags tab. In addition, you can add, modify, and delete tags of an existing instance. For details, see Managing Tags.

   Figure 7 Required duration configuration
   

   Table 7 Required duration

   Parameter	Description
   Required Duration	The length of your subscription if you select Yearly/Monthly billing. Subscription lengths range from one month to three years.
   Auto-renew	This option is not selected by default. If you select this option, the auto-renew cycle is determined by the selected required duration.

5. On the displayed page, confirm instance details.
   • For yearly/monthly instances
     • To modify the configurations, click Previous.
     • If no modification is required, read and agree to the service agreement, click Pay Now, and complete the payment.
   • Pay-per-use
     • To modify the configurations, click Previous.
     • If no modification is required, read and agree to the service agreement and click Submit.

6. On the Instances page, view and manage the created instance.
   • It takes about 5 to 9 minutes to create an instance. During the process, the instance status is Creating.
   • After the creation is complete, the status changes to Available.

     You can click in the upper right corner to refresh the instance status.

   • Automated backup is enabled by default during instance creation. After the instance is created, a full backup is created.