Scenarios

This section describes how to create a Community Edition cluster instance on the DDS management console. Currently, DDS cluster instance of Community Edition supports the yearly/monthly and pay-per-use billing modes. DDS allows you to tailor your compute resources and storage space to your business needs.

You can use your account to create up to 10 cluster instances.

Prerequisites

• You have registered a HUAWEI CLOUD account.
• Your account balance is greater than or equal to ¥0.

Procedure

1. Log in to the DDS console.
2. On the Instance Management page, click Buy DB Instance.
3. On the displayed page, select a billing mode, select your DB instance specifications and click Next.
   Figure 1 Billing mode and basic information
   

   Table 1 Billing mode

   Parameter

   Description

   Billing Mode

   Select a billing mode, Yearly/Monthly or Pay-per-use. Yearly/Monthly You need to set Validity Period as required. Then, the system deducts the fees incurred at one time from your account based on the service price. When you renew a yearly/monthly DB instance, you can change its billing mode from yearly/monthly to pay-per-use based on your service requirements. For details, see Changing Yearly/Monthly Instances to a Pay-per-Use. NOTE: DB instances paid in yearly/monthly mode cannot be deleted. They support only resource unsubscription. For details, see section Unsubscribing from a Yearly/Monthly DB Instance. Pay-per-use You do not need to set Validity Period because the system deducts the fees incurred from your account based on the service duration. If you want to use a DB instance at a low cost for a long period of time, you can change its billing mode from pay-per-use to yearly/monthly. For details, see Changing the Billing Mode in Batches.

   Table 2 Basic information

   Parameter	Description
   Region	A region where the tenant is located. It can be changed in the upper left corner. NOTE: DB instances deployed in different regions cannot communicate with each other through a private network, and you cannot change the region of a DB instance once it is purchased. Exercise caution when selecting a region.
   DB Instance Name	The DB instance name can be 4 to 64 characters long. It must start with a letter and can contain only uppercase letters, lowercase letters, digits, hyphens (-), and underscores (_). If you buy multiple DB instances, you can only enter 4 to 49 characters to set the DB instance name, and then the system automatically appends a date, time, and serial number to the end of the instance names (format: instance_name-MMDD-HHmmss-SN). After the DB instance is created, you can change its name. For details, see Modifying the DB Instance Name.
   Database Type	Community Edition
   DB Instance Type	Select Cluster. A cluster instance includes three types of nodes: mongos, shard, and config. Each shard and config is a three-node replica set to ensure high availability.
   Compatible MongoDB Version	4.0 3.4 3.2
   CPU Type	Currently, DDS supports two CPU architectures: x86 and Kunpeng. The two architectures have similar capabilities and performance, both of which can meet your service requirements. For details about the instance types, versions, and specifications supported by the two CPU architectures, see DB Instance Specifications.
   Resource Type	If you use DeC, this parameter is displayed. EVS and DSS disks are provided based on whether storage resources are exclusively used. DSS disks provide dedicated storage resources. If you have applied for a storage pool on the DSS page, click the DSS tab and create disks in the obtained storage pool. If you have not applied for an exclusive storage pool, click the EVS disk tab. Then, the created disks use public storage resources.
   Storage Type	If you do not use DeC, the storage type is ultra-high I/O by default. For DeC users, the supported storage types vary depending on the selected resource type. If you select EVS for Resource Type, Storage Type is set to Ultra-high I/O. If you select DSS for Resource Type, Storage Type can be set to Common I/O, High I/O, or Ultra-high I/O.
   Storage Pool	This option is displayed only when you select DSS for Resource Type. The storage pool is physically isolated from other pools and is secure.
   Storage Engine	WiredTiger
   AZ	An AZ is a part of a region with its own independent power supply and network. AZs are physically isolated but can communicate through an internal network. Currently, instances can be deployed in a single AZ or three AZs. If you want to deploy an instance in a single AZ, select one AZ. If you want to deploy an instance across AZs for disaster recovery, select three AZs. In this deployment mode, the nodes are evenly distributed in the three AZs.
   Disk Encryption	Disabled: Disable the encryption function. Enabled: Enable the encryption function. This feature improves data security but slightly affects read/write performance. Key Name: Select or create a private key, which is the tenant key. NOTE: After a DB instance is created, the disk encryption status and the key cannot be changed. The backup data stored in OBS is not encrypted. The key cannot be disabled, deleted, or frozen when being used. Otherwise, the database becomes unavailable. For details about how to create a key, see the "Creating a CMK" section in the Data Encryption Workshop User Guide.

   Figure 2 Instance specifications
   

   Table 3 Specifications

   Parameter	Description
   Specifications	In the x86 CPU architecture, the following specifications can be selected to suit different application scenarios: General-purpose (s6), Enhanced (c3), and Enhanced II (c6). For details about the supported DB instance specifications, see DB Instance Specifications.
   Dedicated Cloud	If you use DeC, this parameter is displayed. For details about DB instance specifications in your DeC, see Database Instance Specifications.
   mongos class	For details about the mongos CPU and memory, see DB Instance Specifications. After a DB instance is created, you can change its CPU and memory. For details, see Changing the CPU or Memory of a Cluster DB Instance.
   mongos quantity	The number of mongos nodes. The value ranges from 2 to 32. After a DB instance is created, you can add mongos nodes if necessary. For details, see section Adding Cluster Instance Nodes.
   mongos parameter group	The parameters that apply to the mongos nodes. After a DB instance is created, you can change the parameter group of a node to bring out the best performance. For details, see Editing a Parameter Group.
   shard class	For details about the shard CPU and memory, see DB Instance Specifications. After a DB instance is created, you can change its CPU and memory. For details, see Changing the CPU or Memory of a Cluster DB Instance.
   shard storage space	The value ranges from 10 GB to 2000 GB and must be a multiple of 10. After a DB instance is created, you can scale up its storage space. For details, see Scaling Up Storage Space.
   shard quantity	The number of shard nodes. The shard node stores user data but cannot be accessed directly. The value ranges from 2 to 32. After a DB instance is created, you can add shard nodes if necessary. For details, see Adding Cluster Instance Nodes.
   shard parameter group	The parameters that apply to the shard nodes. After a DB instance is created, you can change the parameter group of a node to bring out the best performance. For details, see Editing a Parameter Group.
   config class	The CPU and memory of a config node. The config node stores the DB instance configurations but cannot be accessed directly. For details, see DB Instance Specifications.
   config storage space	The storage space is 20 GB and cannot be scaled up.
   config parameter group	The parameters that apply to the config nodes. After a DB instance is created, you can change the parameter group of a node to bring out the best performance. For details, see Editing a Parameter Group.

   Figure 3 Network and database configuration
   

   Table 4 Network

   Parameter	Description
   VPC	The VPC where your DB instances are located. A VPC isolates networks for different services, so you can easily manage and configure internal networks and change network configuration. For details about how to create a VPC, see section "Creating a VPC" in the Virtual Private Cloud User Guide. For details about the constraints on the use of VPCs, see Connection Methods. If there are no VPCs available, DDS allocates resources to you by default. NOTE: After the DDS instance is created, the VPC cannot be changed.
   Subnet	A subnet provides dedicated network resources that are logically isolated from other networks for network security. After the instance is created, you can change the private IP address assigned by the subnet. For details, see Changing a Private IP Address.
   Security Group	A security group controls access between DDS and other services for security. If there are no security groups available, DDS allocates resources to you by default. NOTE: Ensure that the security group rule you set allows clients to access DB instances. For example, select the TCP protocol with inbound direction, input the default port number 8635, and enter a subnet IP address or select a security group that the DB instance belongs to.
   SSL	Secure Sockets Layer (SSL) certificates set up encrypted connections between clients and servers, preventing data from being tampered with or stolen during transmission. You can enable SSL to improve data security. After a DB instance is created, you can connect to it using SSL.
   IPv6	Before enabling IPv6, ensure that IPv6 has been enabled for the VPC and subnet where the DB instance is located. For details about the application scenarios and procedures for enabling IPv6 for the VPC and subnet, see IPv4 and IPv6 Dual-Stack Network. After IPv6 is enabled, the DB instance can run in dual-stack mode. It means that the DB instance can use both the IPv4 address and IPv6 address. The DB instance can access the Internet using either IPv4 or IPv6 addresses, and the communications are independent of each other.

   Table 5 Database configuration

   Parameter	Description
   Password	Configure Enter and confirm the administrator password for connecting to the DB instance. Skip Set the administrator password later. When you need to connect to the DB instance, locate the DB instance and click Reset Password in the Operation column to set a password for connecting to the DB instance.
   Administrator	The default account is rwuser.
   Administrator Password	Set a password for the administrator. The password is a string of 8 to 32 characters. It must be a combination of uppercase letters, lowercase letters, digits, and special characters. You can also use the following special characters: ~!@#%^*-_=+? Keep this password secure. If lost, the system cannot retrieve it for you.
   Confirm Password	Enter the administrator password again.
   Enterprise Project	Only enterprise users can use this function. To use this function, contact customer service. An enterprise project is a cloud resource management mode, in which cloud resources and members are centrally managed by project. Select an enterprise project from the drop-down list. The default project is default. To customize an enterprise project, click Enterprise in the upper right corner of the console. The Enterprise Management page is displayed. For details, see Creating an Enterprise Project in the Enterprise Management User Guide.

   Table 6 Tag

   Parameter

   Description

   Tags

   This setting is optional. Adding tags helps you better identify and manage your DB instances. Up to 20 tags can be added for a DB instance. A tag is composed of a key-value pair. Key: Mandatory if the DB instance is going to be tagged Each tag key must be unique for each DB instance. A tag key consists of up to 36 characters. The key can only consist of digits, letters, underscores (_), and hyphens (-). Value: Optional if the DB instance is going to be tagged The value consists of up to 43 characters. The value can only consist of digits, letters, underscores (_), dots (.), 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 Tag.

   Table 7 Required duration and quantity

   Parameter	Description
   Validity Period	Sets the service duration if you select the Yearly/Monthly billing mode. The service duration ranges from one month to three years.
   Auto-renew	By default, this option is not selected. If you select this option, the auto-renew cycle is determined by the selected required duration.
   Quantity	The purchase quantity depends on the cluster instance quota. If your current quota does not allow you to purchase the required number of instances, you can apply for increasing the quota as prompted. The yearly/monthly DB instances that are purchased in batches have the same specifications except for the DB instance name and ID.

   

   DB instance performance is determined by how you configure it during the creation. The hardware configuration items that can be selected include the node class and storage space.

4. On the displayed page, confirm the DB instance information.
   • Yearly/Monthly
     • If you need to modify the specifications, click Previous to return to the previous page.
     • If you do not need to modify your settings, click Pay Now to go to the payment page and complete the payment.
   • Pay-per-use
     • 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 the instance creation.

5. After a DDS DB instance is created, you can view and manage it on the Instance Management page.
   • When a DB instance is being created, the status displayed in the Status column is Creating. This process takes about 15 minutes. After the creation is complete, the status changes to Available.
   • DDS enables the automated backup policy by default. After a DB instance is created, you can modify or disable the automated backup policy. An automated full backup is immediately triggered after the creation of a DB instance.
   • The default DDS port is 8635, but this port can be modified if necessary. If you change the port, you need to add the security group rule to enable access.
   • The yearly/monthly DB instances that are purchased in batches have the same specifications except for the DB instance name and ID.