This topic describes the default read weights of read-only RDS instances of ApsaraDB RDS for MySQL instances that run RDS High-availability Edition and secondary nodes in ApsaraDB RDS for MySQL clusters regardless of the instance types. An ApsaraDB RDS for MySQL cluster refers to an ApsaraDB RDS for MySQL instance that runs RDS Cluster Edition. If you set the Read Weight Distribution parameter to Automatic when you create a database proxy endpoint, you can view the default read weights in this topic.
Default read weights
The following tables describe the default read weights of read-only RDS instances that run RDS High-availability Edition and secondary nodes in an RDS cluster.
For more information about the instance types of read-only RDS instances, see Instance types for standard read-only ApsaraDB RDS for MySQL instances (original x86 architecture) and Instance types for YiTian read-only ApsaraDB RDS for MySQL instances (original ARM architecture).
RDS High-availability Edition
Standard RDS instances on RDS High-availability Edition
Standard RDS instances that run RDS High-availability Edition and use local disks
Instance family | Instance type | Number of CPU cores and memory capacity | Read weight |
General-purpose instance family | rds.mysql.t1.small | 1 core, 1 GB | 100 |
rds.mysql.s1.small | 1 core, 2 GB | 100 | |
rds.mysql.s2.large | 2 cores, 4 GB | 200 | |
rds.mysql.s2.xlarge | 2 cores, 8 GB | 200 | |
rds.mysql.s3.large | 4 cores, 8 GB | 400 | |
rds.mysql.m1.medium | 4 cores, 16 GB | 400 | |
rds.mysql.c1.large | 8 cores, 16 GB | 800 | |
rds.mysql.c1.xlarge | 8 cores, 32 GB | 800 | |
rds.mysql.c2.xlarge | 16 cores, 64 GB | 1,600 | |
rds.mysql.c2.xlp2 | 16 cores, 96 GB | 1,600 | |
Dedicated instance family (with a large memory capacity) | mysqlro.x8.medium.1 | 2 cores, 16 GB | 200 |
mysqlro.x8.large.1 | 4 cores, 32 GB | 400 | |
mysqlro.x8.xlarge.1 | 8 cores, 64 GB | 800 | |
mysqlro.x8.2xlarge.1 | 16 cores, 128 GB | 1,600 | |
mysqlro.x8.4xlarge.1 | 32 cores, 256 GB | 1,600 | |
mysqlro.x8.8xlarge.1 | 64 cores, 512 GB | 1,600 | |
Dedicated instance family (with a large number of CPU cores) | mysqlro.x4.large.1 | 4 cores, 16 GB | 200 |
mysqlro.x4.xlarge.1 | 8 cores, 32 GB | 400 | |
mysqlro.x4.2xlarge.1 | 16 cores, 64 GB | 800 | |
mysqlro.x4.4xlarge.1 | 32 cores, 128 GB | 1,600 | |
Dedicated host instance family | rds.mysql.st.h43 | 60 cores, 470 GB | 6,000 |
rds.mysql.st.v52 | 90 cores, 720 GB | 3,000 |
Standard RDS instances that run RDS High-availability Edition and use cloud disks
Instance family | Instance type | Number of CPU cores and memory capacity | Read weight |
General-purpose instance family | mysqlro.n2.small.1c | 1 core, 2 GB | 100 |
Dedicated instance family | mysqlro.x2.medium.1c | 2 cores, 4 GB | 200 |
mysqlro.x2.large.1c | 4 cores, 8 GB | 400 | |
mysqlro.x2.xlarge.1c | 8 cores, 16 GB | 800 | |
mysqlro.x2.3large.1c | 12 cores, 24 GB | 1,200 | |
mysqlro.x2.2xlarge.1c | 16 cores, 32 GB | 1,600 | |
mysqlro.x2.3xlarge.1c | 24 cores, 48 GB | 2,400 | |
mysqlro.x2.4xlarge.1c | 32 cores, 64 GB | 3,200 | |
mysqlro.x2.13large.1c | 52 cores, 96 GB | 5,200 | |
mysqlro.x2.13xlarge.1c | 104 cores, 192 GB | 10,400 | |
mysqlro.x4.medium.1c | 2 cores, 8 GB | 200 | |
mysqlro.x4.large.1c | 4 cores, 16 GB | 400 | |
mysqlro.x4.xlarge.1c | 8 cores, 32 GB | 800 | |
mysqlro.x4.3large.1c | 12 cores, 48 GB | 2,400 | |
mysqlro.x4.2xlarge.1c | 16 cores, 64 GB | 1,600 | |
mysqlro.x4.3xlarge.1c | 24 cores, 96 GB | 2,400 | |
mysqlro.x4.4xlarge.1c | 32 cores, 128 GB | 3,200 | |
mysqlro.x4.13large.1c | 52 cores, 192 GB | 10,400 | |
mysqlro.x4.13xlarge.1c | 104 cores, 384 GB | 10,400 | |
mysqlro.x8.medium.1c | 2 cores, 16 GB | 200 | |
mysqlro.x8.large.1c | 4 cores, 32 GB | 400 | |
mysqlro.x8.xlarge.1c | 8 cores, 64 GB | 800 | |
mysqlro.x8.3large.1c | 12 cores, 96 GB | 1,200 | |
mysqlro.x8.2xlarge.1c | 16 cores, 128 GB | 1,600 | |
mysqlro.x8.3xlarge.1c | 24 cores, 192 GB | 2,400 | |
mysqlro.x8.4xlarge.1c | 32 cores, 256 GB | 3,200 | |
mysqlro.x8.13large.1c | 52 cores, 384 GB | 5,200 | |
mysqlro.x8.8xlarge.1c | 64 cores, 512 GB | 5,600 | |
mysqlro.x8.13xlarge.1c | 104 cores, 768 GB | 10,400 |
YiTian RDS instances on RDS High-availability Edition
YiTian RDS instances that run RDS High-availability Edition and use cloud disks
Instance family | Instance type | Number of CPU cores and memory capacity | Read weight |
General-purpose instance family | mysqlro.n2m.small.1c | 1 core, 2 GB | 100 |
mysqlro.n2m.medium.1c | 2 cores, 4 GB | 200 | |
mysqlro.n4m.medium.1c | 2 cores, 8 GB | 200 | |
mysqlro.n8m.medium.1c | 2 cores, 16 GB | 200 | |
mysqlro.n2m.large.1c | 4 cores, 8 GB | 400 | |
mysqlro.n4m.large.1c | 4 cores, 16 GB | 400 | |
mysqlro.n8m.large.1c | 4 cores, 32 GB | 400 | |
mysqlro.n2m.xlarge.1c | 8 cores, 16 GB | 800 | |
mysqlro.n4m.xlarge.1c | 8 cores, 32 GB | 800 | |
mysqlro.n8m.xlarge.1c | 8 cores, 64 GB | 800 | |
Dedicated instance family | mysqlro.x4m.medium.1c | 2 cores, 8 GB | 200 |
mysqlro.x8m.medium.1c | 2 cores, 16 GB | 200 | |
mysqlro.x2m.large.1c | 4 cores, 8 GB | 400 | |
mysqlro.x4m.large.1c | 4 cores, 16 GB | 400 | |
mysqlro.x8m.large.1c | 4 cores, 32 GB | 400 | |
mysqlro.x2m.xlarge.1c | 8 cores, 16 GB | 800 | |
mysqlro.x4m.xlarge.1c | 8 cores, 32 GB | 800 | |
mysqlro.x8m.xlarge.1c | 8 cores, 64 GB | 800 | |
mysqlro.x2m.2xlarge.1c | 16 cores, 32 GB | 1,600 | |
mysqlro.x4m.2xlarge.1c | 16 cores, 64 GB | 1,600 | |
mysqlro.x8m.2xlarge.1c | 16 cores, 128 GB | 1,600 | |
mysqlro.x2m.4xlarge.1c | 32 cores, 64 GB | 3,200 | |
mysqlro.x4m.4xlarge.1c | 32 cores, 128 GB | 3,200 | |
mysqlro.x8m.4xlarge.1c | 32 cores, 256 GB | 3,200 | |
mysqlro.x4m.8xlarge.1c | 64 cores, 256 GB | 5,600 | |
mysqlro.x8m.8xlarge.1c | 64 cores, 512 GB | 5,600 |
RDS Cluster Edition (cloud disks)
Standard RDS instances on RDS Cluster Edition
Standard RDS instances that run RDS Cluster Edition and use general-purpose instance types
Instance type | Number of CPU cores and memory capacity | Read weight |
mysql.n2.medium.xc | 2 cores, 4 GB | 200 |
mysql.n4.medium.xc | 2 cores, 8 GB | 200 |
mysql.n8.medium.xc | 2 cores, 16 GB | 200 |
mysql.n2.large.xc | 4 cores, 8 GB | 400 |
mysql.n4.large.xc | 4 cores, 16 GB | 400 |
mysql.n8.large.xc | 4 cores, 32 GB | 400 |
mysql.n2.xlarge.xc | 8 cores, 16 GB | 800 |
mysql.n4.xlarge.xc | 8 cores, 32 GB | 800 |
mysql.n8.xlarge.xc | 8 cores, 64 GB | 800 |
Standard RDS instances that run RDS Cluster Edition and use dedicated instance types
Instance type | Number of CPU cores and memory capacity | Read weight |
mysql.x2.medium.xc | 2 cores, 4 GB | 200 |
mysql.x4.medium.xc | 2 cores, 8 GB | 200 |
mysql.x8.medium.xc | 2 cores, 16 GB | 200 |
mysql.x2.large.xc | 4 cores, 8 GB | 400 |
mysql.x4.large.xc | 4 cores, 16 GB | 400 |
mysql.x8.large.xc | 4 cores, 32 GB | 400 |
mysql.x2.xlarge.xc | 8 cores, 16 GB | 800 |
mysql.x4.xlarge.xc | 8 cores, 32 GB | 800 |
mysql.x8.xlarge.xc | 8 cores, 64 GB | 800 |
mysql.x2.3large.xc | 12 cores, 24 GB | 1,200 |
mysql.x4.3large.xc | 12 cores, 48 GB | 1,200 |
mysql.x8.3large.xc | 12 cores, 96 GB | 1,200 |
mysql.x2.2xlarge.xc | 16 cores, 32 GB | 1,600 |
mysql.x4.2xlarge.xc | 16 cores, 64 GB | 1,600 |
mysql.x8.2xlarge.xc | 16 cores, 128 GB | 1,600 |
mysql.x2.3xlarge.xc | 24 cores, 48 GB | 2,400 |
mysql.x4.3xlarge.xc | 24 cores, 96 GB | 2,400 |
mysql.x8.3xlarge.xc | 24 cores, 192 GB | 2,400 |
mysql.x2.4xlarge.xc | 32 cores, 64 GB | 3,200 |
mysql.x4.4xlarge.xc | 32 cores, 128 GB | 3,200 |
mysql.x8.4xlarge.xc | 32 cores, 256 GB | 3,200 |
mysql.x2.13large.xc | 52 cores, 96 GB | 5,200 |
mysql.x4.13large.xc | 52 cores, 192 GB | 5,200 |
mysql.x8.13large.xc | 52 cores, 384 GB | 5,200 |
mysql.x8.8xlarge.xc | 64 cores, 512 GB | 6,400 |
mysql.x2.13xlarge.xc | 104 cores, 192 GB | 10,400 |
mysql.x4.13xlarge.xc | 104 cores, 384 GB | 10,400 |
mysql.x8.13xlarge.xc | 104 cores, 768 GB | 10,400 |
YiTian RDS instances on RDS Cluster Edition
YiTian RDS instances that run RDS Cluster Edition and use general-purpose instance types
Instance type | Number of CPU cores and memory capacity | Read weight |
mysql.n2e.small.xc | 1 core, 2 GB | 100 |
mysql.n2e.medium.xc | 2 cores, 4 GB | 200 |
mysql.n4e.medium.xc | 2 cores, 8 GB | 200 |
mysql.n8e.medium.xc | 2 cores, 16 GB | 200 |
mysql.n2e.large.xc | 4 cores, 8 GB | 400 |
mysql.n4e.large.xc | 4 cores, 16 GB | 400 |
mysql.n8e.large.xc | 4 cores, 32 GB | 400 |
mysql.n2e.xlarge.xc | 8 cores, 16 GB | 800 |
mysql.n4e.xlarge.xc | 8 cores, 32 GB | 800 |
mysql.n8e.xlarge.xc | 8 cores, 64 GB | 800 |
YiTian RDS instances that run RDS Cluster Edition and use dedicated instance types
Instance type | Number of CPU cores and memory capacity | Read weight |
mysql.x4e.medium.xc | 2 cores, 8 GB | 200 |
mysql.x8e.medium.xc | 2 cores, 16 GB | 200 |
mysql.x2e.large.xc | 4 cores, 8 GB | 400 |
mysql.x4e.large.xc | 4 cores, 16 GB | 400 |
mysql.x8e.large.xc | 4 cores, 32 GB | 400 |
mysql.x2e.xlarge.xc | 8 cores, 16 GB | 800 |
mysql.x4e.xlarge.xc | 8 cores, 32 GB | 800 |
mysql.x8e.xlarge.xc | 8 cores, 64 GB | 800 |
mysql.x2e.2xlarge.xc | 16 cores, 32 GB | 1,600 |
mysql.x4e.2xlarge.xc | 16 cores, 64 GB | 1,600 |
mysql.x8e.2xlarge.xc | 16 cores, 128 GB | 1,600 |
mysql.x2e.4xlarge.xc | 32 cores, 64 GB | 3,200 |
mysql.x4e.4xlarge.xc | 32 cores, 128 GB | 3,200 |
mysql.x8e.4xlarge.xc | 32 cores, 256 GB | 3,200 |
mysql.x2e.8xlarge.xc | 64 cores, 128 GB | 6,400 |
mysql.x4e.8xlarge.xc | 64 cores, 256 GB | 5,600 |
mysql.x8e.8xlarge.xc | 64 cores, 512 GB | 6,400 |