Alibaba Cloud provides ESSD AutoPL disks based on enhanced SSDs (ESSDs). ESSD AutoPL disks inherit the features and performance of ESSDs and decouple disk capacity from disk performance. When you configure the capacity of ESSD AutoPL disks, you can configure provisioned performance and burst performance settings for the disks based on your business requirements. This topic describes the features, specifications, billing methods, and use scenarios of ESSD AutoPL disks and provides examples on how to configure the disks.
The instance to which an ESSD AutoPL disk is attached exerts pressure on the ESSD AutoPL disk. The performance of all applications that run on the instance, such as Alibaba Cloud Security, CloudMonitor, and Cloud Assistant, is included in the performance statistics of the ESSD AutoPL disk.
Features
ESSD AutoPL disks can deliver the following levels of performance: baseline performance, provisioned performance, and burst performance. The baseline performance of an ESSD AutoPL disk is equivalent to the performance of an ESSD at performance level 1 (PL1 ESSD) that has the same specifications. ESSD AutoPL disks support the performance provision feature and the performance burst feature and can deliver up to 1,000,000 IOPS, a maximum throughput of 4 GB/s, and a maximum performance density of 1,000 IOPS/GiB.
Performance provision
The performance provision feature allows you to configure provisioned performance settings for ESSD AutoPL disks to meet storage requirements that exceed the baseline performance without the need to extend the disks.
Performance burst
By default, the performance burst feature is enabled for ESSD AutoPL disks. The feature allows ESSD AutoPL disks to burst their performance when spikes in read/write workloads occur and reduce the performance to the baseline level at the end of workload spikes.
Scenarios
In addition to the scenarios for which ESSDs are suitable, such as latency-sensitive applications and I/O-intensive workloads, ESSD AutoPL disks are also suitable for the following scenarios:
Scenarios in which disk performance needs to be increased without extending disk capacity.
Scenarios in which business workloads significantly fluctuate and disks need to burst their performance when workload spikes occur.
Disk specifications
The following table describes the specifications of ESSD AutoPL disks.
Performance level | Disk attribute | Specifications |
Baseline performance | Capacity range (GiB) | 1~65,536 |
Maximum IOPS per disk | 50,000 | |
Maximum I/O size (KB) | 16 | |
Maximum throughput per disk (MB/s) | 350 | |
Average random write latency per connection (ms) | 0.2 | |
Formula used to calculate IOPS per disk (baseline IOPS①) | max{min{1,800 + 50 × Capacity, 50,000}, 3,000} | |
Formula used to calculate throughput per disk (baseline throughput①, MB/s) | max{min{120 + 0.5 × capacity, 350}, 125} | |
Provisioned performance | Maximum provisioned IOPS② per disk | 50,000 |
Formula used to calculate IOPS per disk (provisioned IOPS②) | min{Provisioned IOPS, 50,000} | |
Formula used to calculate throughput per disk (provisioned throughput②, MB/s) | 16 KB × Provisioned IOPS/1,024 | |
Burst performance | Burst IOPS③ | min{Burst IOPS supported by the instance type, 1,000,000} |
Burst throughput | min{Throughout supported by the instance type, 4 GB/s} |
①: indicates the baseline performance that an ESSD AutoPL disk can deliver, excluding provisioned performance and burst performance.
②: indicates the provisioned performance that an ESSD AutoPL disk can deliver, in addition to baseline performance.
③: indicates the burst performance that an ESSD AutoPL disk can deliver, in addition to baseline performance and provisioned performance.
The total performance of an ESSD AutoPL disk is the sum of the baseline performance①, provisioned performance②, and burst performance③ and cannot exceed 1,000 IOPS per GiB.
The read/write performance of disks is limited by instance types and disk specifications and cannot exceed any of the limits specified by the instance types or disk specifications. For example, if the maximum disk bandwidth allowed for an instance type is 6 Gbit/s, which can be converted to 750 MB/s, the throughput of each disk on an instance of the instance type cannot exceed 750 MB/s. For information about instance types, see Overview of instance families. If a disk cannot deliver its maximum performance due to the limits of an instance type, we recommend that you upgrade the instance type.
Supported instance families
ESSD AutoPL disks support the same instance families as ESSDs. For information about instance families, see Overview of instance families.
Billing
Billable items and billing rules
You are charged disk capacity fees, provisioned performance fees, and burst performance fees for ESSD AutoPL disks. For information about the billing rules of ESSD AutoPL disks, see Block storage devices.
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.
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.
Total number of burst I/Os ≤ 100,000: All I/O bursts are covered by a free quota of 100,000 burst I/Os. You are not charged burst performance fees.
Total number of burst I/Os > 100,000: Fee cap rules apply to keep the fees that are imposed on burst I/Os bounded. This way, you can achieve high performance without the need to worry about excessive burst performance fees. For more information, see the Burst performance fee cap rules section of this topic.
Burst performance fee cap rules
In extreme business scenarios, a higher-than-expected number of burst IOPS may result in excessive burst performance fees. To resolve the preceding issue, burst performance fee cap rules are applied to ESSD AutoPL disks to limit burst performance fees within a controllable range even in extreme cases.
Fee cap rules
A fee cap rule is triggered to limit burst performance fees when the maximum burst I/O density exceeds 200 IOPS per GiB. The maximum burst I/O density is calculated by using the following formula: Maximum number of burst IOPS/Disk capacity. The following table describes the burst performance fee cap rules.
NoteBurst IOPS excludes the baseline IOPS and the provisioned IOPS.
Total number of burst I/Os (I/Os per hour)
Maximum burst I/O density (IOPS per GiB)
Fee not limited
Fee limited
Common scenario
Up to 100,000
N/A
Fee = Total number of burst I/Os × Unit price of performance bursts. The price of performance bursts is measured in USD per 10,000 I/Os.
No fee (free quota of 100,000 burst I/Os)
I/O glitches occasionally occur.
Greater than 100,000
Up to 200
Not capped
Fee = (Number of burst I/Os - 100,000) × Unit price of performance bursts. The price of performance bursts is measured in USD per 10,000 I/Os.
Business spikes occasionally occur, but the number of burst IOPS does not exceed the threshold for limiting burst performance fees.
Greater than 200
Capped
Fee = min ((Number of burst I/Os - 100,000) × Unit price of performance bursts, Disk capacity fee × 8). The price of performance bursts is measured in USD per 10,000 I/Os.
Disks are under extreme workload that requires high IOPS for an extended period of time.
Billing examples
For example, a 40 GiB ESSD AutoPL disk bursts its performance for 1 hour while the disk is being used. The total number of burst I/Os during the hour is 4,390,000, and the maximum burst I/O density during the hour is 230 IOPS per GiB, which triggers the burst performance fee cap rule to limit the burst performance fees. The following table describes the comparison between the burst performance fees before being limited and the burst performance fees after being limited.
Item
Formula
Burst performance fee
Burst performance fees before being limited
Total number of burst I/Os × Unit price of performance bursts. The price of performance bursts is measured in USD per 10,000 I/Os.
4,390,000 × 0.0015/10,000= USD 0.6585
Burst performance fees after being limited
min ((Number of burst I/Os - 100,000) × Unit price of performance bursts, Disk capacity fee × 8). The price of performance bursts is measured in USD per 10,000 I/Os.
min ((4,390,000 - 100,000) × 0.0015/10,000, 8 × 40 × 0.0005) = USD 0.16
You can go to the Expenses and Costs console to view the burst performance fees and the billing details of ESSD AutoPL disks. For more information, see View billing details.
Pricing
For information about the pricing of ESSD AutoPL disks, see the Pricing tab of the Elastic Compute Service (ECS) product page.
Impacts of overdue payments
If your Alibaba Cloud account has overdue payments for the provisioned performance and the burst performance of ESSD AutoPL disks, Alibaba Cloud stops providing the performance provision feature and the performance burst feature for ESSD AutoPL disks. The baseline performance of the ESSD AutoPL disks is not affected. If you want to continue using the performance provision feature and the performance burst feature for the ESSD AutoPL disks, you must complete the overdue payments. After you complete the overdue payments, the performance provision feature and the performance burst feature become available for the ESSD AutoPL disks.
Configure the provisioned performance and the burst performance of an ESSD AutoPL disk
When you create an ESSD AutoPL disk separately or together with an ECS instance in the ECS console, you can specify a disk capacity and configure the provisioned performance and the burst performance of the disk based on your business requirements to improve disk performance. For information about how to create an ECS instance and create a disk, see Create an instance on the Custom Launch tab and Create an empty data disk.
This section provides an example on how to create an ESSD AutoPL disk in the ECS console and configure the provisioned performance and the burst performance of the disk.
Log on to the ECS console.
In the left-side navigation pane, choose .
In the top navigation bar, select the region and resource group to which the resource belongs.
On the Block Storage (Disks) page, click Create Cloud Disk.
On the Disk page, configure the parameters to create an ESSD AutoPL disk.
In the Storage section, select ESSD AutoPL as the disk category and specify a disk capacity.
Select Performance Provision to enable the performance provision feature for the disk and specify a provisioned IOPS value.
By default, Enable Burst is selected. You can disable the performance burst feature based on your business requirements.
For information about how to configure other parameters on the Disk page, see Create an empty data disk.
