If the business workloads of your PolarDB for MySQL cluster greatly fluctuate and often reach peak levels, you can enable the I/O burst feature for the Enterprise SSDs (ESSDs) AutoPL disks of your cluster. This way, the IOPS of the ESSDs AutoPL disks can exceed the maximum limit, which improves the I/O performance of the cluster and allows the cluster to effectively handle workload surges during peak hours. This topic describes how to enable and disable the I/O burst feature for the ESSDs AutoPL disks of a PolarDB for MySQL cluster in the PolarDB console.
Prerequisites
Your PolarDB for MySQL cluster uses ESSD AutoPL disks as the storage type.
Serverless clusters do not support the I/O burst feature. For more information about serverless clusters, see Overview.
Overview
After you enable the I/O burst feature for the ESSD AutoPL disks of a PolarDB for MySQL cluster, the maximum IOPS and maximum throughput that are supported by the cluster are increased. The following table compares the maximum IOPS and maximum throughput that are supported by a PolarDB for MySQL cluster before and after you enable the I/O burst feature.
If you enable the I/O burst feature for ESSD AutoPL disks on the primary node of a PolarDB for MySQL cluster, the I/O burst feature is automatically enabled for ESSD AutoPL disks on the secondary node of the cluster.
Scenario | Maximum IOPS | Maximum throughput |
I/O burst disabled |
|
|
I/O burst enabled |
|
|
If the throughput of a PolarDB for MySQL cluster reaches the upper limit, the IOPS of the cluster is affected. If the IOPS of a PolarDB for MySQL cluster reaches the upper limit, the throughput of the cluster is affected.
For information about the maximum IOPS and maximum I/O bandwidth of a PolarDB for MySQL cluster, see the "Specifications of compute nodes" section of the Compute node specifications of Standard Edition clusters to pic Compute node specifications of Standard Edition clusters.
The maximum IOPS can be calculated based on the maximum I/O bandwidth by using the following formula:
PolarDB engine version: PolarDB for MySQL Standard Edition.
Maximum IOPS = Maximum I/O bandwidth (Gbit/s) × 1024 × 1024/8/16
In this formula, the number 8 indicates 8 bits. One byte has 8 bits. The number 16 indicates that the amount of data involved in each I/O operation on a PolarDB for MySQL cluster is 16 KB.
Impacts
Enabling or disabling the I/O burst feature does not cause transient connections. In most cases, your business is not affected. In specific cases, the IOPS of the cluster may fluctuate. We recommend that you perform this operation during off-peak hours.
Usage notes
The amount of time required to enable or disable the I/O burst feature varies based on the read and write traffic of the cluster. In most cases, several minutes are required to enable or disable the I/O burst feature.
Billing
Billable items and billing rules
You are charged disk capacity fees, provisioned performance fees, and burst performance fees for ESSD AutoPL disks.
Disk capacity fees: You are charged for the disk capacity of each ESSD AutoPL disk. The baseline performance of an ESSD AutoPL disk is equal to the baseline performance of an ESSD at performance level 1 (PL1 ESSD) that has the same capacity as the ESSD AutoPL disk. For information about the billing rules, see Billing rules for storage.
Provisioned performance fees: You are charged for the provisioned performance of ESSD AutoPL disks based on the pay-as-you-go billing method.
Burst performance fees: You are charged for the burst performance of ESSD AutoPL disks based on the pay-as-you-go billing method.
Billing method | Fee | Performance |
Subscription
Subscription duration: 1 month |
|
|
Pay-as-you-go
Billing duration: 24 hours. |
|
You can use PolarDB storage plans to offset the basic storage usage and the provisioned IOPS to reduce storage costs. For more information, see Storage plans.
You are charged for the I/O burst fee for a PolarDB cluster (including the primary node and the secondary node) based on the pay-as-you-go billing method and billed on an hourly basis. The fee is calculated every 10,000 I/O operations. If the number of I/O operations is lower than 10,000, the fee is calculated as if 10,000 I/O operations were performed.
Procedure
Enable the I/O burst feature when you create a PolarDB for MySQL cluster
Go to the PolarDB cluster buy page.
Set the Storage Type parameter to ESSD AutoPL and enable the I/O burst feature.
Enable or disable the I/O burst feature for a PolarDB for MySQL cluster
Log on to the PolarDB console.
In the left-side navigation pane, click Clusters.
In the upper-left corner, select the region in which the cluster is deployed.
Find the cluster and click its ID.
On the Basic Information page, click Change Storage Configuration in the Distributed Storage section.
On the Change Storage Configuration page, you can change the provisioned IOPS of AutoPL disks and select Disable or Enable for the Enable I/O Burst parameter based on your business requirements.
Set the Switching Time parameter to Switch Now or Switch At.
If you select Switch At, you can specify a point in time within the next 24 hours. The configuration is automatically changed within 30 minutes after the specified point in time.
On the Scheduled Tasks page, you can view the details of the task or cancel the task. For more information, see Scheduled tasks.
Read and select the Terms of Service, and then click Buy Now.