This topic describes the detailed information about Premium ESSD, including its features, performance, scenarios, billing rules, and related operations. You can refer to this topic to decide whether to use Premium ESSDs.
Features
Premium ESSD is a new storage type supported by ApsaraDB RDS. It is compatible with all features of ESSDs. Premium ESSDs support the following features:
Buffer Pool Extension (BPE)
After you enable the Buffer Pool Extension (BPE) feature for an instance, the system expands the buffer pool size of your RDS instance. This improves the overall read and write performance of the instance by accelerating read and write operations. This feature also significantly reduces the impact of the I/O jitter of Premium ESSDs on database operations and improves instance stability. The feature is suitable if you want to significantly improve the I/O performance of your RDS instance without the need to upgrade instance specifications or modify business code. For more information, see Use the I/O acceleration feature of general ESSDs.
I/O performance burst
After you enable the I/O performance burst feature for your RDS instance, the IOPS of the instance is no longer limited by the specified maximum value. This allows the instance to provide higher IOPS during peak hours to meet burst business requirements. The feature is suitable for scenarios that involve heavy and fluctuate I/O loads. For more information, see Use the I/O burst feature of general ESSDs.
Data archiving
After you enable the data archiving feature for you RDS instance, you can archive data that is infrequently accessed to an OSS bucket, which reduces the storage costs by 80% compared to PL1 ESSDs. The feature is suitable if your RDS instance contains tables that are infrequently accessed or modified. For more information, see Use the data archiving feature.
Supported instances
Premium ESSDs are supported by an RDS for MySQL instance that meets the following requirements:
The instance runs High-availability Edition or Cluster Edition.
The billing method of the instance is pay-as-you-go or subscription.
Performance
Baseline I/O performance
The baseline I/O performance of Premium ESSDs has been increased. The following table compares the baseline I/O performance for instances that use Premium ESSDs of different storage capacities before and after the increase. For more information, see [Product changes/Feature changes] The baseline I/O performance of the Premium ESSDs of ApsaraDB RDS instances is increased.
The baseline I/O performance improvement applies only to Premium ESSDs that is equal to or larger than 100 GB in size.
If you use the I/O performance burst feature, the I/O performance will be further improved based on the increased baseline I/O performance.
Storage capacity of Premium ESSD | Baseline I/O performance before the increase (same as PL1 ESSD) | Baseline I/O performance after the increase | Performance increment |
100 GB ≤ Storage capacity < 1,000 GB | I/O bandwidth: 125 MB/s to 350 MB/s IOPS: 6,800 to 50,000 | I/O bandwidth: 225 MB/s to 450 MB/s IOPS: 13,200 to 56,400 | I/O bandwidth: 100 MB/s IOPS: 6,400 |
1,000 GB ≤ Storage capacity < 2,000 GB | I/O bandwidth: 350 MB/s IOPS: 50,000 | I/O bandwidth: 500 MB/s IOPS: 59,600 | I/O bandwidth: 150 MB/s IOPS: 9,600 |
2,000 GB ≤ Storage capacity < 4,000 GB | I/O bandwidth: 350 MB/s IOPS: 50,000 | I/O bandwidth: 550 MB/s IOPS: 62,800 | I/O bandwidth: 200 MB/s IOPS: 12,800 |
4,000 GB ≤ Storage capacity < 16,000 GB | I/O bandwidth: 350 MB/s IOPS: 50,000 | I/O bandwidth: 600 MB/s IOPS: 66,000 | I/O bandwidth: 250 MB/s IOPS: 16,000 |
16,000 GB ≤ Storage capacity < 64,000 GB | I/O bandwidth: 350 MB/s IOPS: 50,000 | I/O bandwidth: 700 MB/s IOPS: 72,400 | I/O bandwidth: 350 MB/s IOPS: 22,400 |
Performance of Premium ESSD features
BPE
Enabling BPE for an RDS instance significantly improves the read/write performance and stability of the instance by reducing the execution duration of SQL statements and mitigating the impact of I/O jitter on database operations. For more information, see Use the I/O acceleration feature of general ESSDs.
I/O performance burst
Enabling the I/O performance burst feature for your RDS instance increases the maximum IOPS and maximum throughput of the instance. The following table compares the maximum IOPS and throughput of a instance before and after the I/O performance burst feature is enabled.
When you enable the I/O performance burst feature for the primary instance, the feature is automatically enabled for the secondary instance. However, the feature is not automatically enabled for read-only nodes. You need to manually enable the feature on the details page of each read-only instance.
I/O performance burst | Maximum IOPS | Maximum throughput |
Disabled |
|
|
Enabled |
|
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For more information about
IOPS incrementandI/O bandwidth increment, see [Product changes/Feature changes] The baseline I/O performance of the Premium ESSDs of ApsaraDB RDS instances is increased.If the throughput of an RDS instance reaches the upper limit, the IOPS of the instance is affected. If the IOPS of an RDS instance reaches the upper limit, the throughput of the instance is affected.
The preceding calculations do not apply to RDS instances that use cloud disks and general-purpose instance types because these types of RDS instances share resources. As a result, the maximum IOPS and maximum I/O bandwidth cannot be guaranteed. For more information, see Instance types for primary ApsaraDB RDS for PostgreSQL instances.
For more information about the maximum IOPS and maximum I/O bandwidth of specific instance types, see Instance types for standard primary ApsaraDB RDS for MySQL instances (original x86 architecture) and Instance types for YiTian primary ApsaraDB RDS for MySQL instances (original ARM architecture).
The following table describes how to calculate the IOPS that corresponds to the maximum I/O bandwidth mentioned in the preceding calculations.
RDS instance
IOPS
Remarks
RDS for MySQL instance
IOPS = Maximum I/O bandwidth for the instance type (Gbit/s) × 1024 × 1024/8/16
In this formula, the value 8 indicates 8 bits, and 8 bits form a byte. The value 16 indicates that the amount of data involved in an I/O operation on an ApsaraDB RDS for MySQL instance is 16 KB.
Data archiving
After you enable the data archiving feature for your RDS instance, data that is infrequently accessed is archived to the specified OSS bucket, which reduces storage costs. However, the performance when accessing archived data is relatively lower.
Scenarios
BPE
The BPE feature is suitable for scenarios that involve high read I/O loads and frequent usage of temporary tables.
I/O performance burst
The I/O performance burst feature is suitable for scenarios with high and fluctuating I/O loads.
Business peaks, large transactions, full table scans, and queries that return large amounts of data can cause increased I/O loads. Therefore, the I/O usage of an instance may approach or reach 100% and becomes the performance bottleneck even when CPU, memory, and storage resources are still sufficient, Before the I/O performance burst feature is introduced, you must upgrade the instance specifications or storage type (such as from PL1 ESSD to PL2 ESSD) of your RDS instance. This may result in the following issues:
If you do not upgrade the instance specifications or storage type, the I/O loads exceeds the maximum I/O performance. As a result, the instance performance degrades, queries time out, and connection errors may occur.
If you upgrade instance specifications, the I/O performance can meet your business requirements. However, the increased CPU, memory, and storage resources are idle and wasted.
If you upgrade the storage type, the I/O usage is increased within the peak hours.However, the storage resources are wasted and costs are increased after the peak hours.
The I/O performance burst feature of Premium ESSDs aims to solve these issues. After you enable the feature, the system automatically increases the maximum I/O performance in case of high I/O loads, and resume the maximum I/O performance when the I/O loads decrease. This provides I/O performance in serverless mode and prevents resource waste and additional costs.
Data archiving
The data archiving feature is suitable if your RDS instance contains tables that are infrequently accessed or modified.
Limits
The storage capacity of Premium ESSDs ranges from 10 GB to 64,000 GB.
You cannot change the storage type of your RDS instance from Premium ESSD to any other storage type. However, you can change the storage type from ESSD to Premium ESSD. For more information, see Change the storage type from ESSD to Premium ESSD.
Billing information
Billing method
Fees for Premium ESSDs = Storage capacity fees + Fees for I/O performance burst + Fees for BPE + OSS Fees for data archiving.
For more information about the billing details of each feature, see the following topics:
The BPE feature is free of charge for RDS for MySQL instances of general-purpose instance types.
Storage capacity fees
The prices for PL2 and PL3 ESSDs are different from those for Premium ESSDs. The price difference in the orders displayed in the console takes precedence when you change the storage type.
Premium ESSDs are more cost-effective than PL2 and PL3 ESSDs in scenarios where an RDS instance handles more I/O operations for a shorter period of time within a specific time period.
You are charged for the storage capacity that you purchase for your RDS instance. The subscription and pay-as-you-go billing methods are supported. The billing rules are the same as those of a PL1 ESSD. For more information, see Billable items.
In the following regions, Premium ESSDs are more cost-effective than PL1 ESSDs regardless of the billing method, and the unit price of a Premium ESSD is lower than the unit price of a PL1 ESSD:
China (Hong Kong), Singapore, Malaysia (Kuala Lumpur), Indonesia (Jakarta), Philippines (Manila), Thailand (Bangkok), Japan (Tokyo), South Korea (Seoul), US (Silicon Valley), US (Virginia), Germany (Frankfurt), UK (London), and UAE (Dubai).
In the following regions, the unit price of a Premium ESSD is the same as the unit price of a PL1 ESSD:
China (Hangzhou), China (Shanghai), China (Beijing), China (Shenzhen), China (Nantong), China (Qingdao), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Heyuan), China (Guangzhou), and China (Chengdu)