Creating a Cluster Instance

Scenarios

This section describes how to create a Community Edition cluster instance on the DDS management console. 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.

Procedure

Log in to the DDS console.
On the Instance Management 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	A region where the tenant is located. It can be changed in the upper left corner. For details, see section Regions and AZs. 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 created. 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 (_). After the DB instance is created, you can change the DB instance name. For details, see section Changing a 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	3.4 3.2
Storage Type	Ultra-high I/O
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.

**Table 2** 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).
mongos class	For details about the mongos CPU and memory, see section DB Instance Specifications. After a DB instance is created, you can change its CPU and memory. For details, see section 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 Parameter Group Settings.
shard class	For details about the shard CPU and memory, see section DB Instance Specifications. After a DB instance is created, you can change its CPU and memory. For details, see section 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.
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 section 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 Parameter Group Settings.
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 Parameter Group Settings.

**Table 3** 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. 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. 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.

**Table 4** Database configuration
Parameter	Description
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.

**Table 5** Tag
Parameter	Description
Tags	This setting is optional. Adding tags helps you better identify and manage your DB instances. Up to 10 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.

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.

On the displayed page, confirm the DB instance information.
- 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.
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.