Constraints

CPU and memory

GeminiDB DynamoDB-Compatible API supports cluster instances.

• For details about specifications of different instance types, see Instance Specifications.
• You can change the specifications to meet your service requirements by following Changing vCPUs and Memory.

Storage

The storage space depends on the selected instance specifications.

Storage can be scaled up or down. For details, see Overview.

Tag

A maximum of 20 tags can be added for each instance.

For more information, see Tag Management.

Free backup storage

GeminiDB DynamoDB-Compatible instances provide free additional backup storage of the same size as you purchased.

For more information, see Backup Storage.

Retention period

The default value is 7 days. The value ranges from 1 to 3660 days.

For more information, see Configuring an Automated Backup Policy.

Instance name

• Can contain 4 to 64 characters.
• Must start with a letter. Only letters (case-sensitive), digits, hyphens (-), and underscores (_) are allowed.

Backup name

• Can contain 4 to 64 characters.
• Must start with a letter. Only letters (case sensitive), digits, hyphens (-), and underscores (_) are allowed.

Parameter template name

• Can contain 1 to 64 characters.
• Only letters (case sensitive), digits, hyphens (-), underscores (_), and periods (.) are allowed.

Password of database administrator rwuser

• Can contain 8 to 32 characters.
• Can contain at least two types of the following characters: uppercase letters, lowercase letters, digits, and special characters ~!@#%^*-_=+? For more information, see Resetting the Administrator Password.
• Keep your password secure. The system cannot retrieve it if it is lost.

Database port

Database port number.

Port 8000 is used by default and cannot be changed for a GeminiDB DynamoDB-Compatible instance.

VPC

After a GeminiDB DynamoDB-Compatible instance is created, the VPC where the instance is deployed cannot be changed.

Security group

A security group controls access between GeminiDB DynamoDB-Compatible API and other services. Ensure that the security group you selected allows your client to access the instance.

If no security group is available, the system creates one for you.

Database access

• If remote access is not enabled, GeminiDB DynamoDB-Compatible instances and their associated ECSs must be in the same VPC subnet.

• The security group must allow access from the associated ECS.

  By default, a GeminiDB DynamoDB-Compatible instance cannot be accessed through an ECS in a different security group. You need to add an inbound rule to the security group.

• The default port of a GeminiDB DynamoDB-Compatible instance is 8000.
• The database port cannot be set during instance creation and cannot be changed after the instance is created.

Instance deployment

The servers where instances are deployed are not directly visible to you. You can only access the instances through IP addresses and database ports.

Restarting a GeminiDB DynamoDB-Compatible instance

• GeminiDB DynamoDB-Compatible instances cannot be restarted through commands. They must be restarted on the console.
• To avoid downtime, you are advised to restart an instance during off-peak hours. Ensure that your application can be reconnected.

Viewing backups of a GeminiDB DynamoDB-Compatible instance

GeminiDB DynamoDB-Compatible instance backups are stored in OBS buckets and are transparent to you.

Changing the CPU or memory of a GeminiDB DynamoDB-Compatible instance

• Second-level intermittent disconnection occurs once when the specifications are changed on a single node. Therefore, the entire instance is intermittently disconnected several times. Ensure that the client can be reconnected. You are advised to change the specifications during off-peak hours.
• For a node whose specifications are being changed, its computing tasks are handed over to other nodes. Change specifications of nodes during off-peak hours to prevent instance overload.

Data restoration

To prevent data loss, you are advised to back up key data before data restoration.

Storage

If the instance storage is full, data cannot be written to databases. You are advised to periodically check the storage.

The storage can be automatically scaled up in case of a sudden surge in data volumes. Enable autoscaling by following Automatically Scaling Up Storage Space.

Recycle bin

• You can move unsubscribed yearly/monthly instances and deleted pay-per-use instances to the recycle bin. You can restore an instance that was deleted up to 7 days ago from the recycle bin.
• The recycle bin is enabled by default and cannot be disabled. Instances in the recycle bin can be retained for 7 days by default. This function is free of charge.
• Currently, you can put a maximum of 100 instances into the recycle bin.
• If you delete an instance running out of storage, it will not be moved to the recycle bin.