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Constraints

To improve the stability and security of DB instances, there are some constraints on the use of DDS. For details, see Table 1.

Table 1 Function constraints

Operation

Constraints

Connecting to a DB instance
  • When connecting to a DB instance over private networks, bind an EIP to the prepared ECS and ensure that the DB instance and the ECS are in the same region, AZ, and VPC subnet.
  • By default, DDS is not accessible from ECSs that are not in the same security group. If the ECS is not in the same group, add an inbound rule to enable access.
  • The default DDS port is 8635, but this port can be modified if necessary.

Deployment

ECSs in which DB instances are deployed are not visible to you. Your applications can access the database only through an IP address and port.

Obtaining permissions of user rwuser

Only the rwuser user permissions are provided on the instance creation page.

For details about the related commands, see Supported and Restricted Commands.

Setting database parameters

Most database parameters in the parameter groups you created can be modified. For details, see Editing a Parameter Template.

Migrating data

You can use command line tools and DRS to migrate data. For details, see Migrating Data.

Storage engine

DDS supports the WiredTiger and RocksDB storage engines.

Restarting a DB instance or a node

DB instances cannot be restarted using commands. They must be restarted on the management console.

Viewing DDS backup files

You can download and view the backup files on the DDS console. For details, see Downloading Backup Files.