Introduction and purchase suggestions for ApsaraDB RDS for SQL Server storage types - ApsaraDB RDS

This topic describes the basic features and performance data of ESSDs for ApsaraDB RDS for SQL Server.

Introduction to storage types

Note

For more information about the performance comparison of different storage types, such as maximum capacity per disk, maximum IOPS, and maximum throughput, see Block storage performance.
The reliability, durability, and read/write performance of disks (ESSDs) meet the requirements specified in the product Service-Level Agreement (SLA). These disks use a distributed architecture and multiple replicas to ensure data reliability. If your RDS instance runs RDS High-availability Edition or RDS Cluster Edition, an automatic switchover can be completed in seconds.

ESSDs

ESSDs are developed by Alibaba Cloud based on the next-generation distributed block storage architecture. ESSDs deliver ultra high storage performance. ESSDs are integrated with 25 Gigabit Ethernet and remote direct memory access (RDMA) technologies. ESSDs can provide lower one-way latencies than standard SSDs and process up to 1 million read and write requests at random per second. ESSDs are provided at the following performance levels (PLs):

PL1 ESSD: An ESSD at performance level (PL) 1.
PL2 ESSD: A PL2 ESSD delivers input/output operations per second (IOPS) and throughput that are approximately twice the IOPS and throughput delivered by a PL1 ESSD.
PL3 ESSD: A PL3 ESSD delivers IOPS that is up to 20 times the IOPS delivered by a PL1 ESSD and delivers throughput that is up to 11 times the throughput delivered by a PL1 ESSD. PL3 ESSDs are suitable for scenarios in which highly concurrent requests must be processed with high I/O performance and at low read and write latencies.

For more information about ESSD performance, see ESSDs.

View the storage type of an RDS instance

Log on to the ApsaraDB RDS console and go to the Basic Information page of the RDS instance. In the Basic Information section of the page, view the storage type of the RDS instance.

Performance data of storage types

Comparison item	ESSD
I/O performance	★★★★★ IOPS: determined by the disk specifications and instance type. I/O latency: 100 to 200 microseconds
Configuration flexibility	★★★★★ Provides various configuration options and supports storage capacity scale-out.
Backup method	Snapshot backup for ESSDs
Speed of backup, read-only instance creation, and instance cloning	★★★★★ The operations can be completed in seconds.
Scale-out duration	★★★★★ Online upgrade. The scale-out can be completed in seconds.
Impact of scale-out	No impact.
Data durability	★★★★★ Provides 99.9999999% data reliability. Supports single-node instances of Basic Edition to reduce costs.

References

For more information, see FAQs about buckets.