When the network configuration of an ApsaraDB RDS for MySQL instance changes — for example, after a zone switch — the network connection between the PolarDB for Xscale 1.0 instance and that RDS instance breaks. The PolarDB for Xscale 1.0 instance can no longer access the affected RDS instance. Manually fixing the database shard connection restores network access without restarting or reconfiguring the instance.
When to use this procedure
Use this procedure when a zone switch or similar network configuration change on an ApsaraDB RDS for MySQL instance has caused connectivity to break. Typical symptoms include:
Write or read operations on the database return connection errors
Applications report that they cannot reach the database after a zone change
For other connection problems — such as authentication failures, incorrect credentials, or RDS instance errors — refer to the relevant troubleshooting documentation instead.
Prerequisites
Before you begin, ensure that you have:
A PolarDB for Xscale 1.0 instance with at least one database that has lost connectivity to its mounted ApsaraDB RDS for MySQL instance after a network configuration change
Access to the PolarDB for Xscale console
Fix shard connections
Log on to the PolarDB for Xscale console.
In the top navigation bar, select the region where the target instance is located.
In the left-side navigation pane, click Instances.
Find the target instance and click the instance ID.
In the left-side navigation pane, choose Configuration and Management > Databases.
Find the target database and click the database name.
On the Basic Information page, click Fix Database Shard Connections in the Shortcuts section.
In the dialog box that appears, click OK.