Delayed replication lets you set a minimum wait time, in seconds, before a read-only instance applies changes from its primary instance.
Prerequisites
Before you begin, ensure that you have:
A read-only instance whose primary instance runs RDS High-availability Edition
Limitations
After you configure the data replication latency for a read-only instance, the read-only instance cannot be added to a read/write splitting link. To add the instance to a read/write splitting link, set the data replication latency back to 0. For more information, see Enable the read/write splitting feature for an ApsaraDB RDS for MySQL instance (shared proxy).
How it works
When the latency is set to 0 (default), the primary instance forwards operation logs to the read-only instance immediately after each operation completes. The read-only instance applies those logs as soon as it receives them.
Set the replication latency
Log on to the ApsaraDB RDS console. In the left-side navigation pane, click Instances. In the top navigation bar, select the region in which the instance resides.
Click the ID of the read-only instance.
In the left-side navigation pane, click Service Availability.
Click Set Delayed Replication.
In the dialog box that appears, enter the replication latency in seconds, then click OK.
Next steps
To re-enable read/write splitting, set the data replication latency to 0 first.