This topic provides an overview of read-only ApsaraDB RDS instance types. The overview includes the latest specifications for each instance type.

ApsaraDB RDS allows you to create read-only RDS instances. These read-only RDS instances are used to increase the read capability of your database system. For more information about read-only RDS instances, see Overview of read-only ApsaraDB RDS for MySQL instances.

For more information about primary ApsaraDB RDS instance types, see Primary instance types.

IOPS for standard and enhanced SSDs

The maximum input/output operations per second (IOPS) of an RDS instance that uses local SSDs varies based on the instance type. The maximum IOPS of an RDS instance that uses standard or enhanced SSDs varies based on the instance type and the storage capacity. The following table lists the formulas that are used to calculate the maximum IOPS of an RDS instance. The RDS instance uses standard or enhanced SSDs.

Note If the throughput of the RDS instance reaches the upper limit, the IOPS is affected.
Storage type Enhanced SSD Standard SSD
PL PL3 PL2 PL1 None

Maximum IOPS

(The storage capacity is measured in GB.)

min{1800 + 50 × Storage capacity, 1000000, Maximum IOPS for the instance type} min{1800 + 50 × Storage capacity, 100000, Maximum IOPS for the instance type} min{1800 + 50 × Storage capacity, 50000, Maximum IOPS for the instance type} min{1800 + 30 × Storage capacity, 25000, Maximum IOPS for the instance type}
The min{1800 + 50 × Storage capacity, 50000, Maximum IOPS for the instance type} formula is used as an example to describe the IOPS values in the preceding table.
  • 1800 + 50 × Storage capacity: the baseline IOPS for the enhanced SSD storage type.
  • 50000: the maximum IOPS per enhanced SSD. For more information about standard and enhanced SSDs and performance levels (PLs), see ESSDs.
  • Maximum IOPS for the instance type: the maximum IOPS for the ECS-limited instance type. For more information about the maximum IOPS for each instance type, see the following specification tables.
The IOPS of the RDS instance is the smallest IOPS among the three IOPS values in the formula that is used. In the following examples, the RDS instance uses enhanced SSDs of PL1.
  • For example, the instance type is mysql.x2.large.2c, the maximum IOPS is 20,000, and the storage capacity is 20 GB. In this case, the baseline IOPS is 2,800 based on the following calculation: 1800 + 50 × 20 = 2800. Therefore, the IOPS of the RDS instance is 2,800.
  • For example, the instance type is mysql.x2.large.2c, and the maximum IOPS is 20,000. In this case, if the storage capacity of the RDS instance exceeds 6,000 GB, the baseline IOPS is 301,800. The baseline IOPS exceeds the smallest IOPS, 20,000, among the three IOPS values. Therefore, the IOPS of the RDS instance is 20,000.
Note
  • If the maximum I/O bandwidth of the RDS instance is reached, the RDS instance may not support the maximum IOPS.
  • The baseline IOPS of an ECS cloud disk allows you to read and write 4 KB of data per second. The default IOPS for MySQL allows you to read and write 16 KB of data. Therefore, each read/write operation on MySQL consumes 4 IOPS.
  • In the specification tables of this topic, if the maximum IOPS and maximum I/O bandwidth (Mbit/s) for an instance type are marked as None, ApsaraDB RDS allows multiple instances of the instance type to preempt resources. In this case, the IOPS is not limited.

Pricing

For more information about the prices of read-only RDS instances, see the following file:

Prices of Subscription Read-only ApsaraDB RDS for MySQL Instances (Specifications)

For more information about the prices of pay-as-you-go RDS instances and storage capacities:

The price of the RDS instance that you want to purchase varies based on the instance configuration, such as the region, instance type, storage capacity that you select. For more information, go to the ApsaraDB RDS buy page.

Read-only ApsaraDB RDS for MySQL instances

Role Database engine version Instance family Instance type CPU and memory specifications Maximum number of connections Maximum IOPS Storage capacity
Read-only instance 5.6, 5.7, and 8.0 General-purpose instance family rds.mysql.t1.small 1 core, 1 GB 300 600 5 GB to 2,000 GB
rds.mysql.s1.small 1 core, 2 GB 600 1,000
rds.mysql.s2.large 2 cores, 4 GB 1,200 2,000
rds.mysql.s2.xlarge 2 cores, 8 GB 2,000 4,000
rds.mysql.s3.large 4 cores, 8 GB 2,000 5,000
rds.mysql.m1.medium 4 cores, 16 GB 4,000 7,000
rds.mysql.c1.large 8 cores, 16 GB 4,000 8,000
rds.mysql.c1.xlarge 8 cores, 32 GB 8,000 12,000
rds.mysql.c2.xlarge 16 cores, 64 GB 16,000 14,000 5 GB to 3,000 GB
rds.mysql.c2.xlp2 16 cores, 96 GB 24,000 16,000
Dedicated instance family (with a large memory capacity) mysqlro.x8.medium.1 2 cores, 16 GB 2,500 4,500 50 GB to 2,000 GB
mysqlro.x8.large.1 4 cores, 32 GB 5,000 9,000 50 GB to 2,000 GB
mysqlro.x8.xlarge.1 8 cores, 64 GB 10,000 18,000 500 GB to 3,000 GB
mysqlro.x8.2xlarge.1 16 cores, 128 GB 20,000 36,000 500 GB to 3,000 GB
mysqlro.x8.4xlarge.1 32 cores, 256 GB 40,000 72,000 1,000 GB to 6,000 GB
mysqlro.x8.8xlarge.1 64 cores, 512 GB 80,000 144,000 1,000 GB to 6,000 GB
Dedicated instance family (with a large number of cores) mysqlro.x4.large.1 4 cores, 16 GB 2,500 4,500 50 GB to 2,000 GB
mysqlro.x4.xlarge.1 8 cores, 32 GB 5,000 9,000 500 GB to 3,000 GB
mysqlro.x4.2xlarge.1 16 cores, 64 GB 10,000 18,000 500 GB to 3,000 GB
mysqlro.x4.4xlarge.1 32 cores, 128 GB 20,000 36,000 1,000 GB to 6,000 GB

Read-only ApsaraDB RDS for SQL Server instances

Role Database engine version Instance family Instance type CPU and memory specifications Maximum number of connections Maximum IOPS Storage capacity
Read-only instance 2017 EE General-purpose instance family rds.mssql.s2.large 2 cores, 4 GB Unlimited For more information, see IOPS for standard and enhanced SSDs. 20 GB to 4,000 GB
rds.mssql.s3.large 4 cores, 8 GB
rds.mssql.c1.large 8 cores, 16 GB
rds.mssql.s2.xlarge 2 cores, 8 GB
rds.mssql.m1.medium 4 cores, 16 GB
rds.mssql.c1.xlarge 8 cores, 32 GB
rds.mssql.c2.xlarge 16 cores, 64 GB
Dedicated instance family mssql.x4.medium.ro 2 cores, 8 GB
mssql.x4.large.ro 4 cores, 16 GB
mssql.x4.xlarge.ro 8 cores, 32 GB
mssql.x4.2xlarge.ro 16 cores, 64 GB
mssql.x4.4xlarge.ro 32 cores, 128 GB
mssql.x4.8xlarge.ro 64 cores, 256 GB
mssql.x8.medium.ro 2 cores, 16 GB
mssql.x8.large.ro 4 cores, 32 GB
mssql.x8.xlarge.ro 8 cores, 64 GB
mssql.x8.2xlarge.ro 16 cores, 128 GB
mssql.x8.4xlarge.ro 32 cores, 256 GB
mssql.x8.7xlarge.ro 56 cores, 480 GB
mssql.x8.8xlarge.ro 64 cores, 512 GB

Read-only ApsaraDB RDS for PostgreSQL instances (with local SSDs)

Role Database engine version Instance family Instance type CPU and memory specifications Maximum number of connections Maximum IOPS Storage capacity
Read-only instance

10

Dedicated instance family (with a large memory capacity) pg.x8.xlarge.2 8 cores, 64 GB 10,000 18,000 20 GB to 6,000 GB
pg.x8.2xlarge.2 16 cores, 128 GB 12,000 36,000
Dedicated instance family (with a large number of cores) pg.x4.xlarge.2 8 cores, 32 GB 5,000 9,000
pg.x4.2xlarge.2 16 cores, 64 GB 10,000 18,000
pg.x4.4xlarge.2 32 cores, 128 GB 12,000 36,000
Dedicated host instance family rds.pg.st.h43 60 cores, 470 GB 4,000 50,000

Read-only ApsaraDB RDS for PostgreSQL instances (with standard or enhanced SSDs)

Role Database engine version Instance family Instance type CPU and memory specifications Maximum number of connections Maximum IOPS Storage capacity
Read-only instance

13, 12, 11, and 10

General-purpose instance family pgro.n2.small.1c 1 core, 2 GB 200 For more information, see IOPS for standard and enhanced SSDs. 50 GB to 32,000 GB
pgro.n2.medium.1c 2 cores, 4 GB 400
Dedicated instance family pgro.x2.medium.1c 2 cores, 4 GB 400
pgro.x2.large.1c 4 cores, 8 GB 800
pgro.x2.xlarge.1c 8 cores, 16 GB 1,600
pgro.x2.3large.1c 12 cores, 24 GB 2,400
pgro.x2.2xlarge.1c 16 cores, 32 GB 3,200
pgro.x2.3xlarge.1c 24 cores, 48 GB 4,800
pgro.x2.4xlarge.1c 32 cores, 64 GB 6,400
pgro.x2.13large.1c 52 cores, 104 GB 10,400
pgro.x2.8xlarge.1c 64 cores, 128 GB 12,800
pgro.x2.13xlarge.1c 104 cores, 192 GB 19,200
pgro.x4.medium.1c 2 cores, 8 GB 800
pgro.x4.large.1c 4 cores, 16 GB 1,600
pgro.x4.xlarge.1c 8 cores, 32 GB 3,200
pgro.x4.3large.1c 12 cores, 48 GB 4,800
pgro.x4.2xlarge.1c 16 cores, 64 GB 6,400
pgro.x4.3xlarge.1c 24 cores, 96 GB 9,600
pgro.x4.4xlarge.1c 32 cores, 128 GB 12,800
pgro.x4.13large.1c 52 cores, 192 GB 19,200
pgro.x4.8xlarge.1c 64 cores, 256 GB 25,600
pgro.x4.13xlarge.1c 104 cores, 384 GB 38,400
pgro.x8.medium.1c 2 cores, 16 GB 1,600
pgro.x8.large.1c 4 cores, 32 GB 3,200
pgro.x8.xlarge.1c 8 cores, 64 GB 6,400
pgro.x8.3large.1c 12 cores, 96 GB 9,600
pgro.x8.2xlarge.1c 16 cores, 128 GB 12,800
pgro.x8.3xlarge.1c 24 cores, 192 GB 19,200
pgro.x8.4xlarge.1c 32 cores, 256 GB 25,600
pgro.x8.13large.1c 52 cores, 384 GB 38,400
pgro.x8.8xlarge.1c 64 cores, 512 GB 51,200
pgro.x8.13xlarge.1c 104 cores, 768 GB 76,800

Read-only ApsaraDB RDS for PPAS instances

Role Database engine version Instance family Instance type CPU and memory specifications Maximum number of connections Maximum IOPS Storage capacity
Read-only instance

10

General-purpose instance family rds.ppas.t1.small 1 core, 1 GB 100 1,200 150 GB
Dedicated instance family ppas.x4.small.2 1 core, 4 GB 200 5,000 250 GB
ppas.x4.medium.2 2 cores, 8 GB 400 10,000
ppas.x8.medium.2 2 cores, 16 GB 2,500 15,000
ppas.x4.large.2 4 cores, 16 GB 2,500 20,000 250 GB or 500 GB
ppas.x8.large.2 4 cores, 32 GB 5,000 30,000
ppas.x4.xlarge.2 8 cores, 32 GB 5,000 40,000 500 GB or 1,000 GB
ppas.x8.xlarge.2 8 cores, 64 GB 10,000 60,000
ppas.x4.2xlarge.2 16 cores, 64 GB 10,000 80,000 1,000 GB or 2,000 GB
ppas.x8.2xlarge.2 16 cores, 128 GB 12,000 120,000
ppas.x4.4xlarge.2 32 cores, 128 GB 12,000 160,000 2,000 GB or 3,000 GB
ppas.x8.4xlarge.2 32 cores, 256 GB 12,000 240,000
Dedicated host instance family rds.ppas.st.h43 60 cores, 470 GB 12,000 450,000 3,000 GB or 4,000 GB or 5,000 GB or 6,000 GB