PL1 enhanced SSDs (ESSDs) deliver higher IOPS, higher throughput, and more stable I/O performance than standard SSDs — at the same price in most regions. Upgrading your ApsaraDB RDS for MySQL instance from a standard SSD to a PL1 ESSD improves database performance at no extra cost in most cases.
Prerequisites
Before you begin, make sure that:
The RDS instance is in the Running state
The RDS instance runs MySQL 8.0 or MySQL 5.7 on RDS High-availability Edition or RDS Basic Edition with standard SSDs
(RDS Basic Edition only) The minor engine version is 20201031 or later. To check and update the minor engine version, see Upgrade the minor engine version
Performance comparison
The following table compares PL1 ESSDs and standard SSDs. All metrics reflect per-disk values.
| Metric | PL1 ESSD | Standard SSD |
|---|---|---|
| Maximum capacity (GB) | 20–64,000 | 6,000 |
| Maximum IOPS | 50,000 | 25,000 |
| Maximum throughput (MB/s) | 350 | 300 |
| IOPS formula | min{1,800 + 50 × Capacity, 50,000} | min{1,800 + 30 × Capacity, 25,000} |
| Throughput formula (MB/s) | min{120 + 0.5 × Capacity, 350} | min{120 + 0.5 × Capacity, 300} |
| Average write latency per connection (ms) | 0.2 | 0.5–2 |
Billing
The upgrade may incur the following charges:
Backup: The system performs a temporary full backup before the upgrade and retains it for seven days. Backup storage fees may apply. For details, see Backup storage fees.
ESSD fee: The fee varies by region. The exact amount is shown on the payment page before you confirm the upgrade.
Potential impacts
Transient connection: A transient connection of approximately 30 seconds occurs during the upgrade. Schedule the upgrade during off-peak hours and make sure your application is configured to reconnect automatically.
Restricted operations: While the upgrade is in progress, the instance enters the Upgrading/Downgrading state. During this time, you cannot change instance specifications, upgrade the database engine version, or migrate the instance across zones.
Tip: Before upgrading a production instance, test the procedure on a non-production instance to confirm the expected behavior.
Upgrade the storage type
Go to the Instances page. In the top navigation bar, select the region where your RDS instance resides. Find the instance and click its ID.
In the Basic Information section, click Upgrade Storage Type next to Storage Type.
If Upgrade Storage Type is not displayed, check that all prerequisites are met. If all prerequisites are met but the button is still missing, ESSDs are not supported in the current region.
On the Change Specifications tab, read and accept the terms of service. Click Pay Now and complete the payment.
The instance status changes to Upgrading/Downgrading. When the status returns to Running, the upgrade is complete.
FAQ
Why can't I select ESSD as the storage type?
The zones where your instance resides may not have sufficient resources or may not support ESSDs. To resolve this, first update the minor engine version. Then migrate the instance to zones that support ESSDs and retry the upgrade.
Are read-only instances upgraded automatically?
No. After upgrading the primary instance, repeat the procedure for each read-only instance individually.
Do the instance endpoints change after the upgrade?
Endpoints remain unchanged after the storage type change (for example, rm-bpxxxxx.mysql.rds.aliyuncs.com). However, the IP addresses associated with the endpoints may change. Add endpoints to your application configuration rather than IP addresses.
Are online workloads interrupted during the upgrade?
For more information, see the Potential impacts section of this topic.
What factors affect how long the upgrade takes?
For details, see Which factors affect the time required to change the specifications of my ApsaraDB RDS for MySQL instance?
API reference
| Operation | Description |
|---|---|
| ModifyDBInstanceSpec | Changes the specifications of an instance |