The I/O burst feature of general Enterprise SSDs (ESSDs) decouples input/output operations per second (IOPS) from storage capacity, letting your RDS instance handle traffic spikes without requiring you to provision a higher-performance disk tier. To help you explore this feature, Alibaba Cloud is offering it free of charge for a limited time.
For background on how the feature works, see Performance of general ESSDs. To enable it on your instance, see Use the I/O burst feature.
Effective date
Starting from June 20, 2024.
The end date has not been announced. Alibaba Cloud will notify you via text message, email, and internal message before the event ends.
Event details
During the event: The I/O burst feature is free of charge — all burstable I/O operations are covered at no extra cost.
After the event ends: A free quota applies per RDS edition. You pay only for burstable I/O operations that exceed your instance's free quota.
| RDS edition | Free quota after the event |
|---|---|
| RDS Basic Edition | 300,000 I/O operations per hour (up from 100,000) |
| RDS High-availability Edition | 600,000 I/O operations per hour (up from 200,000) |
| RDS Cluster Edition | 800,000 I/O operations per hour (up from 500,000) |
More IOPS-related promotions with significant discounts and free offerings are planned before this event ends.
Billing
Billing applies only to burstable I/O operations on general ESSDs. The total fee for a general ESSD is:
Total fee = Storage capacity fee + Burstable I/O operations fee
Burstable I/O operations are billed on a pay-as-you-go basis, with bills generated hourly.
Unit price
USD 0.0015 per 10,000 I/O operations.
If the number of excess burstable I/O operations in an hour is less than 10,000, you are charged for 10,000 operations.
How the hourly fee is calculated
Hourly fee = (Total burstable I/O operations across all RDS instances in the database system
− Free quota for the RDS edition)
× Unit priceExample 1: Minimal overage
Scenario: An RDS High-availability Edition instance performs 602,000 burstable I/O operations in one hour.
| Value | |
|---|---|
| Actual burstable I/O operations | 602,000 per hour |
| Free quota | 600,000 per hour |
| Excess | 2,000 (rounded up to 10,000, the minimum billing unit) |
| Fee | 10,000 × USD 0.0015 / 10,000 = USD 0.0015 |
Example 2: Monthly cost estimate
Scenario: An RDS High-availability Edition instance with 1,000 GB of storage in the China (Beijing) region. Baseline IOPS is 50,000. The instance bursts at 20,000 IOPS for 40 seconds every hour throughout a month.
| Value | |
|---|---|
| Actual burstable I/O operations | 800,000 per hour |
| Free quota | 600,000 per hour |
| Excess per hour | 200,000 |
| Monthly fee | USD 0.0015 × (80 − 60) × 24 × 30 = USD 21.6 |
Cost comparison: general ESSD vs. PL2 ESSD
The following table compares the monthly cost of a 1,000 GB general ESSD (with I/O burst) against an ESSD of performance level 2 (PL2).
| Storage type | Storage unit price (USD/month) | Storage cost (USD) | I/O burst fee (USD) | Total (USD/month) |
|---|---|---|---|---|
| General ESSD | 244.8 | 244.8 | 21.6 | 266.4 |
| PL2 ESSD | 489.6 | 489.6 | N/A | 489.6 |
What's next
Performance of general ESSDs — understand baseline and burst IOPS for your storage size
Use the I/O burst feature — enable and monitor I/O burst on your instance