Read-only ApsaraDB RDS for SQL Server instances are independently provisioned replicas that offload read traffic from the primary instance. Each read-only instance replicates data from the primary instance and scales independently to match your read workload.
Read-only instances support subscription and pay-as-you-go billing. Serverless is not supported. Actual prices are subject to the sales page.
Instances with disk-based storage are built on Elastic Compute Service (ECS). Different instances may use different ECS instance families, which can result in performance differences.
Read-only instance types
The actual maximum IOPS and I/O throughput at runtime are determined by the storage class, storage capacity, and instance type. The final value is the minimum of two limits:
Instance type limit: The values in the table below reflect the ceiling imposed by the instance type's hardware.
Storage limit: Calculate the storage-based ceiling using the formula for maximum IOPS or the formula for maximum throughput.
The following table lists all supported instance types for SQL Server 2022 EE (Always On), SQL Server 2019 EE (Always On), and SQL Server 2017 EE (Always On).
| Instance family | Instance type code | CPU and memory | Maximum connections | Maximum IOPS | Maximum I/O throughput (MB/s) | Storage capacity |
|---|---|---|---|---|---|---|
| General-purpose | rds.mssql.s2.large | 2 cores, 4 GB | Unlimited | 10,000 | 128 | 20 GB–32,000 GB |
| rds.mssql.s3.large | 4 cores, 8 GB | 20,000 | 10,000 | 192 | ||
| rds.mssql.c1.large | 8 cores, 16 GB | 25,000 | 10,000 | 256 | ||
| rds.mssql.s2.xlarge | 2 cores, 8 GB | 10,000 | 10,000 | 128 | ||
| rds.mssql.m1.medium | 4 cores, 16 GB | 20,000 | 10,000 | 192 | ||
| rds.mssql.c1.xlarge | 8 cores, 32 GB | 25,000 | 10,000 | 256 | ||
| rds.mssql.c2.xlarge | 16 cores, 64 GB | 40,000 | 10,000 | 384 | ||
| Dedicated | mssql.x4.medium.ro | 2 cores, 8 GB | 10,000 | — | 128 | |
| mssql.x4.large.ro | 4 cores, 16 GB | 20,000 | — | 192 | ||
| mssql.x4.xlarge.ro | 8 cores, 32 GB | 25,000 | — | 256 | ||
| mssql.x4.2xlarge.ro | 16 cores, 64 GB | 40,000 | — | 384 | ||
| mssql.x4.4xlarge.ro | 32 cores, 128 GB | 60,000 | — | 640 | ||
| mssql.x4.8xlarge.ro | 64 cores, 256 GB | 120,000 | — | 1,280 | ||
| mssql.x8.medium.ro | 2 cores, 16 GB | 10,000 | — | 128 | ||
| mssql.x8.large.ro | 4 cores, 32 GB | 20,000 | — | 192 | ||
| mssql.x8.xlarge.ro | 8 cores, 64 GB | 25,000 | — | 256 | ||
| mssql.x8.2xlarge.ro | 16 cores, 128 GB | 40,000 | — | 384 | ||
| mssql.x8.4xlarge.ro | 32 cores, 256 GB | 60,000 | — | 640 | ||
| mssql.x8.7xlarge.ro | 56 cores, 480 GB | 120,000 | — | 1,280 | ||
| mssql.x8.8xlarge.ro | 64 cores, 512 GB | 120,000 | — | 1,280 |
What's next
该文章对您有帮助吗？