RDS for MariaDB Constraints

Storage space

Cloud SSD: 40 GB to 4,000 GB

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Connections

A maximum of 100,000 for 512 GB of memory

The default maximum number of connections varies depending on the memory. For details, see What Is the Maximum Number of Connections to an RDS DB Instance?

IOPS

Cloud SSD: a maximum of 50,000

The input/output operations per second (IOPS) supported depends on the I/O performance of Elastic Volume Service (EVS) disks. For details, see the description about ultra-high I/O in Disk Types and Performance of Elastic Volume Service Service Overview.

Read replica

A maximum of five read replicas can be created for a DB instance.

For more information, see Introducing Read Replicas.

Tags

A maximum of 20 tags can be added for a DB instance.

For more information, see Managing Tags.

Free backup space

RDS for MariaDB provides free backup space of the same size as your purchased storage space.

After you pay for the storage space of your DB instance, you will get a backup space of the same size for free. For more information, see How Is RDS Backup Data Billed?

Retention period of automated backups

The default value is 7 days. The value ranges from 1 to 732 days.

For more information, see Configuring an Intra-Region Backup Policy.

Log retention period

• Error log details: 30 days
• Slow query log details: 30 days

For more information, see Log Management.

Instance name

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

Database name

• 1 to 64 characters long
• Only letters, digits, hyphens (-), and underscores (_) are allowed. The total number of hyphens (-) cannot exceed 10.

Account name

• 1 to 32 characters long
• Only letters, digits, hyphens (-), and underscores (_) are allowed.

Backup name

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

Parameter template name

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

root permissions

Only the administrator account root is provided on the instance creation page. For details about the supported permissions, see Tabla 6.

root password

• 8 to 32 characters long
• Must contain at least three types of the following characters: uppercase letters, lowercase letters, digits, and special characters (~!@$#%^*-_=+?,()&).

For more information, see Resetting the Administrator Password to Restore Root Access.

Database port

1024 to 65535 (excluding 12017 and 33071, which are occupied by the RDS system)

For more information, see Changing a Database Port.

VPC

The VPC where a DB instance is located cannot be changed after the instance is created.

Security group

• By default, you can create a maximum of 100 security groups in your cloud account.
• By default, you can add up to 50 security group rules to a security group. For more information, see Configuring a Security Group Rule.
• One RDS DB instance can be associated with multiple security groups, and one security group can be associated with multiple RDS DB instances.

System account

To provide O&M services, the system automatically creates system accounts when you create RDS for MariaDB DB instances. These system accounts are unavailable to you.

• mariadb.sys: used to create views.
• rdsAdmin: a management account, used to query and modify instance information, rectify faults, migrate data, and restore data.
• rdsRepl: a replication account, used to synchronize data from the primary instance to the standby instance or read replicas.
• rdsBackup: a backup account, used for backend backup.
• rdsMetric: a metric monitoring account used by watchdog to collect database status data.
• rdsProxy: a database proxy account, used for authentication when the database is connected through the read/write splitting address. This account is automatically created when you enable read/write splitting.

Instance parameter

To ensure the optimal performance of RDS, you can modify parameters in the parameter template you created as needed.

Instance deployment

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

Data synchronization

You can synchronize data from self-managed MariaDB databases or MariaDB databases built on other clouds to RDS for MariaDB, or from one RDS for MariaDB instance to another RDS for MariaDB instance.

The common data synchronization tool is Data Replication Service (DRS). For details, see From MariaDB to RDS for MariaDB.

DRS is easy to use and can complete a synchronization task in minutes. DRS facilitates data transfer between databases, helping you reduce DBA labor costs and hardware costs.

High CPU usage

If the CPU usage is high or close to 100%, data read/write and database access will become slow, and an error will be reported during data deletion.

Full storage

There is not enough storage available for a DB instance and the instance becomes read-only, so applications cannot write any data to the instance.

For details, see What Should I Do If an RDS DB Instance Is Abnormal Due to Full Storage Space?

Number of tables

RDS for MariaDB supports a maximum of 500,000 tables.

If there are more than 500,000 tables, database backup or a minor version upgrade may fail.

Rebooting a DB instance

DB instances cannot be rebooted through commands. They must be rebooted through the RDS console. For details, see Rebooting DB Instances or Read Replicas.

Viewing backups

You can download automated and manual backups for local storage. To download a backup, you can use OBS Browser+, the current browser, or the download URL.

For more information, see Downloading a Full Backup File.

Log management

• RDS for MariaDB logging is enabled by default and cannot be disabled.
• Binary logging is enabled for RDS for MariaDB by default and uses row-based logging.
• Read replicas do not provide binlogs.

Recycle bin

RDS allows you to move deleted pay-per-use DB instances to the recycle bin. You can rebuild a DB instance that was deleted up to 7 days ago from the recycle bin.

Select

Table

Query permissions

Yes

Insert

Table

Insert permissions

Update

Table

Update permissions

Delete

Table

Delete permissions

Create

Database, table, or index

Permissions of creating databases, tables, or indexes

Drop

Database or table

Permissions of deleting databases or tables

Reload

Server management

Permissions of running the following commands: flush-hosts, flush-logs, flush-privileges, flush-status, flush-tables, flush-threads, refresh, and reload

Process

Server management

Permissions of viewing processes

Grant

Database, table, or stored program

Permissions of granting access control

References

Database or table

Foreign key operation permissions

Index

Table

Index permissions

Alter

Table

Permissions of altering tables, such as adding fields or indexes

Show_db

Server management

Permissions of viewing database connections

Create_tmp_table

Server management

Permissions of creating temporary tables

Lock_tables

Server management

Permissions of locking tables

Execute

Stored procedure

Permissions of executing storage procedures

Repl_slave

Server management

Replication permissions

Repl_client

Server management

Replication permissions

Create_view

View

Permissions of creating views

Show_view

View

Permissions of viewing views

Create_routine

Stored procedure

Permissions of creating storage procedures

Alter_routine

Stored procedure

Permissions of altering storage procedures

Create_user

Server management

Permissions of creating users

Event

Database

Event triggers

Trigger

Database

Triggers

Super

Server management

Permissions of killing threads

No

File

File on the server

Permissions of accessing files on database server nodes

No

Shutdown

Server management

Permissions of shutting down databases

Create_tablespace

Server management

Permissions of creating tablespaces