ApsaraDB for MongoDB provides replica set instances. These instances are suitable for scenarios in which the number of read operations is larger than the number of write operations or the number of operations surges due to impromptu events. These scenarios are common in websites that provide online reading services and in systems that provide order queries. This topic describes how to create replica set instances in the ApsaraDB for MongoDB console.

Prerequisites

  • You are registered with Alibaba Cloud. For more information, see Sign up with Alibaba Cloud.
  • If you want to create standalone instances that are charged based on the pay-as-you-go billing method, the balance in your Alibaba Cloud account is sufficient.

Billing

ApsaraDB for MongoDB supports the subscription billing method and the pay-as-you-go billing method. You can select a billing method based on your business requirements.
  • Subscription: If you purchase a subscription instance, you must pay an upfront fee for the instance.
  • Pay-as-you-go: A pay-as-you-go instance is charged per hour based on the configuration of the instance. Fees are automatically deducted from your Alibaba Cloud account.

For more information, see Billable items and pricing.

Precautions

If your application is deployed on an Elastic Compute Service (ECS) instance, make sure that your replica set instance and the ECS instance meet the following requirements to ensure network connectivity:
  • Your replica set instance and the ECS instance belong to the same region. You can view the region of a created ECS instance. For more information, see View instance information.
  • Optional:Your replica set instance and the ECS instance belong to the same zone. This reduces network latency. You can view the zone of a created ECS instance. For more information, see View instance information.
  • Your replica set instance and the ECS instance reside in the same type of network. You can view the network type of a created ECS instance. For more information, see View instance information. If an ECS instance resides in the classic network, you can migrate the ECS instance from the classic network to a virtual private cloud (VPC). For more information, see Migrate an ECS instance from the classic network to a VPC.

Procedure

After you perform the following steps, ApsaraDB for MongoDB automatically creates standalone instances. No manual intervention is required.

  1. Log on to the ApsaraDB for MongoDB console.
  2. In the upper-left corner of the page, select the resource group and the region of the target instance.
  3. In the left-side navigation pane, click Replica Set Instances.
  4. On the Replica Set Instances page, click Create Instance.
  5. Click the Replica Set (Subscription) tab or the Replica Set (Pay-as-you-go) tab.
  6. Configure the following parameters.
    Section Parameter Description
    Basic Configuration Region The region to which the replica set instances belong.
    Note
    • After the replica set instances are created, you cannot change the region of the instances. Proceed with caution when you select a region.
    • If your application is deployed on an ECS instance, the replica set instances and the ECS instance must belong to the same region. If the replica set instances and the ECS instance belong to different regions, your application cannot communicate with the replica set instances over an internal network.
    Zone The zone to which the replica set instances belong.
    Note
    • If your application is deployed on an ECS instance, we recommend that you make sure that the replica set instances and the ECS instance belong to the same zone. This helps you reduce the network latency between your application and the replica set instances. If the replica set instances run MongoDB 4.2 or earlier, you can migrate the instances to different zones. For more information, see Migrate an ApsaraDB for MongoDB instance to different zones in the same region.
    • You can select multiple zones for the replica set instances to achieve zone-disaster recovery. For more information, see Create a multi-zone replica set instance.
    Database Version The MongoDB version of the replica set instances. Valid values:
    • MongoDB 4.2
    • MongoDB 4.0
    • MongoDB 3.4
    Note When a replica set instance is in the Running state, you can manually upgrade the MongoDB version of the instance. For more information, see Upgrade MongoDB versions.
    Storage Engine The storage engine of the replica set instances. Select WiredTiger.
    Nodes The number of nodes in each replica set instance. Set this parameter based on your business requirements.
    Network Type Network Type The type of network in which the replica set instances reside. We recommend that you select VPC.
    • Classic Network: In the classic network, you can block unauthorized traffic only by configuring security groups or IP address whitelists.
    • VPC: A VPC is an isolated virtual network that provides higher security and higher performance than the classic network.
      Note If your application is deployed on an ECS instance, you must make sure that the ECS instance resides in a VPC. This ensures the network connectivity between your application and the replica set instances.
    VPC ID The ID of the VPC to which the replica set instances belong. If no VPCs are available, you can create a VPC in the VPC console. For more information, see Create a VPC.
    Note
    VSwitch The ID of the vSwitch to which the replica set instances belong. If no vSwitches are available, you can create a vSwitch in the VPC console. For more information, see Create a vSwitch.
    Specifications Specification The number of cores and memory capacity that are configured for each replica set instance. For more information about the specifications that are supported by replica set instances, see Instance types.
    Storage Space The storage capacity of each replica set instance.
    Note The storage capacity is used to store your data files, system files, and log files.
    Set Password Set Password The time when you want to set the password of the root account. Valid values:
    Password The password of the root account. If you set the Set Password parameter to Set Now, you must set the password of the root account in compliance with the following rules:
    • The password must contain at least three of the following character types: uppercase letters, lowercase letters, digits, and special characters. The password can contain the following special characters:

      !@ # $ % ^ & * ( ) _ + - =

    • The password must be 8 to 32 characters in length.
    Purchase quantity Duration The subscription period of the replica set instances. This parameter appears only for replica set instances that are charged based on the subscription billing method. Valid monthly subscription periods range from one month to nine months. Valid yearly subscription periods range from one year to three years.
    Quantity The number of replica set instances that you want to create. All the created replica set instances have the same specifications. Valid values: 1 to 20.
  7. Confirm the order and complete the payment.
    1. Confirm the parameter settings and click Buy Now.
    2. On the Confirm Order page, confirm the parameter settings, read and select ApsaraDB for MongoDB Agreement of Service, and then complete the payment.
  8. Check whether the replica set instances are created.
    1. After you complete the payment, click Console to go to the ApsaraDB for MongoDB console.
    2. In the upper-left corner of the page, select the resource group and region to which the replica set instances belong.
    3. In the left-side navigation pane, click Replica Set Instances.
    4. In the instance list that appears, check whether the standalone instances that you created are displayed.
      • If the standalone instances are displayed, the instances are created. If the standalone instances are in the Running state, the instances are running as expected.
      • If the standalone instances are not displayed, wait for 10 minutes to 15 minutes. Then, refresh the page. If the standalone instances are still not displayed, check whether the issues that are described in the following table occur. If none of the issues occur, contact Alibaba Cloud technical support.
        The following table describes the possible causes of and solutions to the issues due to which the created standalone instances are not displayed.
        Possible cause Solution
        The standalone instances do not belong to the region that you select. In the top navigation bar of the ApsaraDB for MongoDB console, select the resource group and region to which the standalone instances belong.
        The standalone instances do not belong to the type of instance that you select. In the left-side navigation pane of the ApsaraDB for MongoDB console, click Replica Set Instances.
        The standalone instances are not created due to insufficient resources.

        Go to the Billing Management console and open the Orders page to check whether you receive refunds.

        After you confirm the refunds, perform one of the following operations:

Related operations

Operation Description
CreateDBInstance
  • Creates an ApsaraDB for MongoDB standalone instance or replica set instance.
  • Clones an ApsaraDB for MongoDB standalone instance or replica set instance.
DescribeInstanceAutoRenewalAttribute Queries whether auto-renewal is enabled for an ApsaraDB for MongoDB instance.
DescribeDBInstanceAttribute Queries the details about an ApsaraDB for MongoDB instance.

What to do next

After standalone instances are created, perform the following operations:
  • Optional:If you did not set the password of the root user for the standalone instances when you created the instances, set the password of the root user. For more information, see Reset the password.
  • Configure IP address whitelists for the standalone instances. The IP address whitelists of a standalone instance contain the IP addresses or CIDR blocks that are granted access to the standalone instance. For more information, see Configure a whitelist for an ApsaraDB for MongoDB instance.
  • Optional:If you want to connect to a standalone instance over the Internet, apply for a public endpoint for the standalone instance. For more information, see Apply for a public endpoint for an ApsaraDB for MongoDB instance.