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ApsaraDB RDS:I/O performance burst feature

Last Updated:May 22, 2025

If your business experiences significant fluctuations with frequent peak periods, you can enable the I/O performance burst feature for premium performance disks. This allows your disk's IOPS to exceed the maximum IOPS limit during peak periods, providing higher I/O capabilities to meet your burst business requirements. This topic describes how to enable and disable the I/O performance burst feature for premium performance disks of RDS MySQL instances by using the console and API operations.

Prerequisites

The storage type of the RDS MySQL instance is premium performance disk.

Feature introduction

After the I/O performance burst feature is enabled for premium performance disks, the maximum IOPS and throughput limits of the instance increase. The following table describes the differences between instances with and without the I/O performance burst feature enabled:

Note

When you enable the I/O performance burst feature for a primary instance, the feature is also enabled for the secondary instance. The feature is not automatically enabled for read-only instances. You need to enable it on the details page of each read-only instance.

Scenario

Maximum IOPS

Maximum throughput

I/O performance burst disabled

min{50000+Enhanced IOPS value,Maximum IOPS of instance type,IOPS corresponding to the maximum I/O bandwidth of instance type,1800+50x Storage capacity+Enhanced IOPS value}

min{350+Enhanced I/O bandwidth value,Maximum I/O bandwidth of instance type,120+0.5x Storage capacity+Enhanced I/O bandwidth value} (Unit: MB/s)

I/O burst enabled

min{1000000,Maximum IOPS of instance type,IOPS corresponding to the maximum I/O bandwidth of instance type}

min{4000,Maximum I/O bandwidth of instance type} (Unit: MB/s)

Note

Behavior

The process of enabling or disabling the I/O performance burst feature does not cause transient connections. In most cases, this process does not affect your business. In some cases, the IOPS of the RDS instance may fluctuate. We recommend that you perform this operation during off-peak hours.

Limit

Enabling or disabling the I/O performance burst feature takes several minutes. The specific time depends on the usage of the instance (read and write traffic).

Fees

Note

A fee exemption campaign is in progress for the I/O performance burst feature of premium performance disks. Starting from June 20, 2024, no fees are charged for using the I/O performance burst feature. Discounts will still be available after the campaign ends. For more information, see [Campaign/Price Adjustment] Fee exemption campaign for the I/O performance burst feature of RDS premium performance disks.

Billing description

Billing unit price

Hourly I/O performance burst fee of an instance = (Total I/O performance burst volume of all nodes in the instance - Free quota) × Unit price

I/O performance burst unit price: USD 0.0015 per 10,000 I/O operations.

Note

The I/O performance burst volume fees for premium performance disks of RDS instances (including primary and secondary nodes) are charged only on a pay-as-you-go basis. The fees are calculated and billed on an hourly basis in units of 10,000 I/O operations. If the number of I/O operations is less than 10,000, the system charges fees for 10,000 I/O operations.

Free I/O performance burst volume quota

The following table describes the free quotas for I/O performance burst volumes of premium performance disks for different RDS instance types:

Instance type

Free quota

RDS Basic Edition

300,000 per hour

RDS High-availability Edition

600,000 per hour

RDS Cluster Edition

800,000 per hour

Instance I/O performance burst volume: Sum of I/O performance burst volumes of all nodes in the instance

RDS edition

Instance I/O performance burst volume

RDS Basic Edition

I/O performance burst volume of the single node

RDS High-availability Edition

I/O performance burst volume of the primary node + I/O performance burst volume of the secondary node

RDS Cluster Edition

I/O performance burst volume of the primary node + I/O performance burst volumes of all secondary nodes

Note
  • If the I/O loads on the primary RDS instance are heavy and an I/O burst is triggered, an I/O burst is also triggered on the secondary RDS instance to ensure data and service consistency. The I/O performance burst volume of the secondary node is basically the same as that of the primary node.

  • The I/O performance burst feature for read-only instances must be enabled separately. The billing standard is the same as that for primary nodes. If a read-only instance is of RDS High-availability Edition, the fees include the I/O performance burst fees for both the primary and secondary nodes.

I/O performance burst volume of a single node: Part that exceeds the baseline IOPS or throughput × Duration

Note

Baseline I/O performance refers to the initial I/O performance of a premium performance disk, which is the maximum IOPS and throughput when the I/O performance burst feature is disabled.

Example scenario

A user purchases an RDS High-availability Edition instance (with primary and secondary nodes) with a 200 GB premium performance disk. The baseline IOPS of the instance is 12,000.

After the I/O performance burst feature is enabled: During the period from 00:00:00 to 01:00:00, I/O bursts occur from 00:00:00 to 00:00:27 and from 00:53:00 to 00:53:33, with IOPS consistently at 22,000. During the rest of the time, the IOPS does not exceed the baseline value, and no I/O bursts occur.

Burst time

In the preceding example, burstable I/O operations are generated and the total burst time is 60 seconds. The value 60 is obtained by using the following calculation: 27 + 33 = 60.

I/O performance burst volume of a single node in the hour

(22,000 - 12,000) × 1 × 60 = 600,000.

Total I/O performance burst volume of the instance in the hour

600,000 + 600,000 = 1,200,000. The numbers of burstable I/O operations on the primary and secondary RDS instances are each 600,000.

Billing example

For example, if the I/O performance burst volume of an RDS High-availability Edition instance is 602,000 I/O operations per hour, the I/O performance burst fee is calculated as follows:

Actual I/O performance burst volume

602,000 I/O operations per hour

Free quota

600,000 I/O operations per hour

Excess over quota

2,000 I/O operations

Actual I/O performance burst fee

10,000 × USD 0.0015 per 10,000 I/O operations = USD 0.0015

Enable or disable I/O performance burst

  1. Visit the RDS instance list, select a region at the top, and click the ID of the target instance.

  2. In the Basic Information > Storage Type section, click Premium Performance Disk Switch Settings to the right of Premium Performance Disk, and enable or disable the I/O Performance Burst feature.

References

Related API operation

API

Description

Modify an RDS instance

When you configure the I/O performance burst feature for premium performance disks:

  • Make sure that the value of the DBInstanceStorageType parameter is general_essd, which indicates that the storage type of the instance is premium performance disk.

  • The BurstingEnabled parameter controls whether to enable or disable the I/O performance burst feature. Set this parameter to true to enable the feature or false to disable the feature.

  • Do not modify other parameters, such as the instance type and storage capacity.