This topic describes the concept, performance, maximum performance, scenarios, billing rules, and related operations of Premium ESSDs to help you decide whether to use Premium ESSDs.
Introduction
Premium ESSD is a new storage type supported by ApsaraDB RDS. Premium ESSDs are compatible with all features of ESSDs features and provide better baseline I/O performance than PL1 ESSDs. Premium ESSDs also support the I/O burst, Buffer Pool Extension (BPE), and data archiving features.
Buffer Pool Extension (BPE)
After you enable the Buffer Pool Extension (BPE) feature, the system expands the size of the cache pool of your RDS instance. This accelerates caching and improves the overall read/write performance of the RDS instance. The 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 burst
After you enable the I/O burst feature, the IOPS of your RDS instance is no longer limited by the maximum IOPS. This provides higher I/O capabilities during peak hours to meet burst business requirements. The feature is suitable for scenarios in which I/O loads are heavy and fluctuate. For more information, see I/O burst feature.
Data archiving
After you enable the data archiving feature, you can store data that is infrequently accessed to an OSS bucket and the storage costs are reduced by 80% compared to PL1 ESSDs. The feature is suitable if your RDS instance contains infrequently accessed or modified tables. For more information, see Data archiving feature.
Applicable services
All RDS instance types (cloud disk version) support Premium ESSDs.
Serverless RDS MySQL instances currently support only the I/O burst feature of Premium ESSDs.
Performance of Premium ESSDs
Baseline I/O performance
The baseline I/O performance of Premium ESSDs has been improved. The following table shows the differences in baseline performance improvement for Premium ESSDs with different storage capacities. For more information, see [Product changes/Feature changes] The baseline I/O performance of Premium ESSDs for ApsaraDB RDS instances is increased.
This performance improvement requires that the storage capacity of Premium ESSDs is not less than 100 GB.
After the baseline I/O performance is improved, the I/O burst feature will be based on the improved baseline I/O performance.
Storage capacity of Premium ESSD | Baseline before the increase (same as PL1 ESSD) | Baseline after the increase | 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
Buffer Pool Extension (BPE)
After you enable Buffer Pool Extension (BPE), you can effectively improve read/write performance, reduce SQL execution time, and reduce the impact of I/O jitter on database operations, which improves stability. For more information, see Use the I/O acceleration feature of general ESSDs.
I/O burst
After you enable the I/O burst feature for Premium ESSDs, the maximum IOPS and maximum throughput of your instance will increase. The following table shows the differences between instances with and without the I/O burst feature enabled:
When you enable the I/O burst feature for a primary instance, the feature is automatically enabled for the secondary instance. For read-only instances, you need to enable the feature on the details page of each read-only instance.
Scenario | Maximum IOPS | Maximum throughput |
I/O burst disabled |
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I/O burst enabled |
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For more information about
IOPS incrementandI/O bandwidth increment, see Baseline I/O performance improvement of Premium ESSDs for RDS.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 formulas do not apply to RDS instances that use general-purpose instance types with cloud disks because these instance types share resources and cannot guarantee maximum IOPS and maximum I/O bandwidth.
For more information about the maximum IOPS and maximum I/O bandwidth for 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 product
IOPS calculation
Remarks
RDS MySQL
IOPS = Maximum I/O bandwidth for the instance type (Gbit/s) × 1024 × 1024/8/16
In this calculation, 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 Premium ESSDs and archive infrequently accessed data, you can reduce storage costs. However, the performance when accessing archived data is relatively lower.
Scenarios
Buffer Pool Extension (BPE)
Buffer Pool Extension (BPE) is suitable for scenarios with high read I/O loads and frequent use of temporary tables.
I/O burst
Premium ESSDs are 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 all cause increased I/O loads. Sometimes, even when CPU, memory, and storage space are relatively sufficient, the I/O usage may approach or reach 100%. In these scenarios, you must upgrade the instance specifications or storage type of your RDS instance. For example, you can upgrade the storage type from ESSD PL1 to ESSD PL2.
If you do not upgrade the instance specifications or storage type, the I/O loads reach the upper limit. As a result, the instance performance decreases, queries time out, and connection errors occur.
If you upgrade instance specifications, the I/O performance can meet your business requirements, but the CPU, memory, and storage resources are idle and wasted.
If you upgrade the storage type, the I/O usage is increased within a short period of time, but storage resources are wasted and costs are increased when the I/O loads decrease.
The I/O burst feature of Premium ESSDs can solve these problems. After you enable the I/O burst feature, when I/O loads are high, the system automatically triggers I/O burst to increase the I/O limit. When I/O loads decrease, the I/O limit is automatically restored. This provides serverless I/O performance and prevents waste of I/O performance and costs.
Data archiving
Data archiving is suitable if your RDS instance contains infrequently accessed or modified tables.
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 rules
Billing method
Premium ESSD fee = RDS storage space fee + I/O burst fee + Buffer Pool Extension (BPE) fee + Data archiving OSS fee.
For more information about the billing details of each feature, see the following topics:
The Buffer Pool Extension (BPE) feature is free for RDS MySQL general-purpose instance types.
RDS storage space fee
The fees for ESSD (PL2, PL3) and Premium ESSDs differ. The price difference is shown in the order displayed in the console when you change the storage type.
Within a specific time period, if an RDS instance handles many I/O operations for a shorter period of time, Premium ESSDs are more cost-effective than PL2 and PL3 ESSDs.
Premium ESSD fee = Storage space fee + I/O burst fee + Buffer Pool Extension (BPE) fee + Data archiving OSS fee.
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).
NoteThe price difference between a Premium ESSD and a PL1 ESSD varies based on the billing method:
Pay-as-you-go: Premium ESSDs can be up to 60% more cost-effective than PL1 ESSDs.
Subscription: Premium ESSDs can be up to 43% more cost-effective than PL1 ESSDs.
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)