Traffic spikes — seasonal promotions, product launches, and similar events — demand extra compute capacity for a limited window. A temporary upgrade lets you boost a PolarDB subscription cluster's specifications for a set period and automatically scales the cluster back to its original specifications when the restore time you choose arrives, with no manual intervention required.
Prerequisites
Before you begin, ensure that you have:
A subscription (annual or monthly) PolarDB cluster
No pending renewal, upgrade, downgrade, or temporary upgrade orders on the cluster
Limitations
| Constraint | Detail | Workaround |
|---|---|---|
| No temporary downgrades | Only upgrades are supported. | N/A |
| Cannot add or remove nodes during a temporary upgrade | Horizontal scaling and automatic scaling are disabled while the upgrade is active. | Permanently upgrade the cluster. See Permanently retain the temporarily upgraded specifications. |
| Minimum validity period: 1 hour | The restore time must be at least 1 hour after the upgrade takes effect. | N/A |
| Recommended maximum validity period: 14 days | The restore time cannot be changed after it is set, so plan carefully before placing the order. | If you need more time, perform a second temporary upgrade before the first one expires. The second restore time must not be earlier than the first. |
| Restore time must be at least one day before the cluster expiration date | For example, if the cluster expires on January 10, the restore time must be January 9 or earlier. | If the cluster is close to its expiration date, renew it first, or permanently upgrade the cluster instead. |
Transient connections to the cluster may occur when the cluster scales up or scales back. Make sure your application can automatically reconnect.
Billing
The temporary upgrade fee is 1.5 times the daily price difference between the new and original specifications, multiplied by the number of days in the validity period.
Formula:
Fee = (Monthly fee for new specifications - Monthly fee for original specifications) / 30 x 1.5 x NWhere N is the number of days in the validity period.
Select different specifications for the primary node and read-only nodes
In a PolarDB cluster, you can perform separate temporary upgrades for the primary node and read-only nodes, giving each a different specification.
Limits:
At least one read-only node must have the same specifications as the primary node.
The memory of a read-only node cannot be less than half of the primary node's memory.
CPU core correspondence:
| Primary node CPU cores | Minimum read-only node CPU cores |
|---|---|
| 2 | 2 |
| 4 | 4 |
| 8 | 4 |
| 16 | 8 |
| 32 | 16 |
| 64 | 32 |
| 88 | 32 |
Perform a temporary upgrade
Log on to the PolarDB console.
In the upper-left corner, select the region where the cluster is deployed.
On the Clusters page, find the target cluster.
Open the Change Configurations (Subscription) dialog box using one of these methods:
In the Actions column, click Change Configurations.
Click the cluster ID to go to the Basic Information page. In the Database Nodes section, click Change Configurations.
Select Temporary Upgrade and click OK.
Temporary Upgrade is available only for subscription clusters.
Configure the upgrade parameters.
Parameter Description Specification type The specification type of the upgraded cluster. Defaults to Dedicated. Node The new node specifications. At least one read-only node must have the same specifications as the primary node. PolarProxy type The PolarProxy type of the upgraded cluster. Defaults to Dedicated Enterprise. Restore time The time when the cluster scales back to the original specifications. The restore time cannot be changed after the order is placed. Accept the terms of service and click Buy Now.
On the Purchase page, confirm the order and click Purchase.
Permanently retain the temporarily upgraded specifications
To keep the temporarily upgraded specifications permanently, perform a manual upgrade while the temporary upgrade is still active (the cluster is in the running state). When you do this, the cluster does not scale back when the restore time is reached.
In the Change Configurations dialog box, select Upgrade. For details, see Change the specifications of a PolarDB cluster.
This operation does not affect your business.
What's next
To add or remove read-only nodes after the temporary upgrade expires, see Add or remove a read-only node.
To change specifications permanently, see Change the specifications of a PolarDB cluster.