Rolling Back the Version of a DDM Instance

Scenarios

After a DDM instance is upgraded to a new version, the kernel version can be rolled back to the version before the last update.

Precautions

• Rolling back to the kernel version will restart your DDM instance, and this may interrupt your workloads for a while. Perform this upgrade during off-peak hours or make sure that your applications can be automatically reconnected.
• The version can only be rolled back to the version before the last upgrade.
• If nodes are added after version updates, you need to scale in the new nodes and then roll back the version.
• If the kernel version is earlier than 3.1.6.0, only JDK 8 is supported, and the rollback is performed on the node.
• If the kernel version is 3.1.6.0 or later, JDK 17 is supported. If the rollback involves cross-JDK version transition, the node is created for upgrade. The time takes longer than that of local change.
  • The upgrade duration is longer than that of the local upgrade and depends on the number of groups and nodes. Nodes in the same group and subnet are created concurrently. The upgrade time window needs to be evaluated.
  • Before the change, ensure that there are no residual XA transactions.
  • If a GSI has been created, delete it before the downgrade. Otherwise, the original GSI will be reused after the upgrade, causing data query errors.
  • If no load balancer is available, in the upper right corner of the management console, choose Service Tickets > Create Service Ticket to submit a service ticket.
  • An EIP bound to a node will be automatically bound to a new node after the upgrade, which may interrupt services. You are advised to perform the upgrade during off-peak hours.
• If SSL is enabled in a later version and the JDK version is downgraded to a version that does not support SSL, disable SSL. If SSL is required after the upgrade, manually enable SSL. For details, see Enabling and Disabling SSL for an Instance.

Procedure

1. Log in to the DDM console.
2. On the Instances page, locate the instance whose version you want to upgrade and click its name.
3. On the Basic Information page, in the Instance Information area, click Roll Back Version beside the Version field.
4. In the displayed dialog box, click OK.
5. Confirm and click Yes.
6. When the rollback is under progress, the instance status changes to Rolling back.
7. After the rollback is complete, the instance status changes from Rolling back to Running, and the instance version becomes the target version.