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What Should I Do If the Network Connection Between the Replication Instance and Database Is Abnormal?

Before data migration, ensure that network preparations and security rule settings are complete. If the connection is abnormal, check whether the network configuration is correct.

This section uses the migration from MySQL to RDS MySQL as an example to describe three migration scenarios: cross-cloud real-time migration, on-premises database migration, and real-time migration of self-built ECS databases.

Cross-Cloud Real-Time Migration

  1. Network settings
    Enable public accessibility for the source database.
    • Source database network settings:

      Enable public accessibility for the source database.

      For example, if you want to migrate a MySQL database from Alibaba Cloud to the MySQL database on the current cloud, you need to apply for a public IP address to make your source database accessible from outside applications. For details, see related documents provided by Alibaba Cloud.

    • Destination database network settings:

      By default, the destination database and the DRS replication instance are in the same VPC and can communicate with each other. No further configuration is required.

  2. Security rules
    • Source database security group settings:

      Add the EIP of the replication instance to the whitelist of the source MySQL DB instance to allow the access from the EIP.

      For example, if you want to migrate a MySQL database from Alibaba Cloud to a MySQL database on the current cloud, you need to set the source database whitelist by referring to related documents provided by Alibaba Cloud.

      Before configuring the whitelist for the source database, you need to obtain the EIP of the DRS replication instance. You can find the EIP on the Configure Source and Destination Databases page after creating the replication instance on the DRS console.

      You can also add 0.0.0.0/0 to the source database whitelist to allow any IP address to access the source database but you must ensure that the above does not pose a risk to your services.

      After the migration is complete, you can delete the configuration from the whitelist.

    • Destination database security group settings:

      By default, the destination database and the DRS replication instance are in the same VPC and can communicate with each other. No further configuration is required.

Real-Time Migration of On-Premises Databases

  1. Network settings
    • Source database network settings:

      You can migrate on-premises MySQL databases to the MySQL databases on the current cloud through a VPN or public network. Enable public accessibility or establish a VPN for the on-premises MySQL databases based on the site requirements. You are advised to migrate data through a public network, which is more convenient and cost-effective.

    • Destination database network settings:
      • If the source database attempts to access the destination database through a VPN, you need to ensure that the VPN service is enabled and the source database can communicate with the destination MySQL database.
      • If the source database attempts to access the destination database through a public network, you do not need to configure the destination database.
  2. Security rules
    1. Source database security group settings:
      • If the migration is performed over a public network, add the EIP of the DRS replication instance to the network whitelist of the source MySQL database to enable the source MySQL database to communicate with the current cloud. Before setting the network whitelist, you need to obtain the EIP of the replication instance.

        The IP address on the Configure Source and Destination Databases page is the EIP of the replication instance.

      • If the migration is performed over a VPN network, add the private IP address of the DRS migration instance to the network whitelist of the source MySQL database to enable the source MySQL database to communicate with the current cloud. The IP address on the Configure Source and Destination Databases page is the private IP address of the replication instance.

      After the migration is complete, you can delete the rules.

    2. Destination database security group settings:

      By default, the destination database and the DRS replication instance are in the same VPC and can communicate with each other. No further configuration is required.

Real-Time Migration of Self-Built Databases on the ECS

  1. Network settings
    • The source and destination databases must be in the same region.
    • The source and destination databases can be either in the same VPC or different VPCs.
      • If the source and destination databases are in the same VPC, the networks are interconnected by default.
      • If the source and destination databases are in different VPCs, the subnets of the source and destination databases are required to be in different CIDR blocks. You need to create a VPC peering connection between the two VPCs.
  2. Security rules
    • In the same VPC, the network is connected by default. You do not need to set a security group.
    • In different VPCs, establish a VPC peering connection between the two VPCs. You do not need to set a security group.
Parent topic: Network and Security