Overview

This topic describes the considerations, process, and restrictions for upgrading OceanBase Migration Service (OMS) to V4.0.2.

Background

OMS V3.2.1 and later support rollback during the upgrade. We recommend that you use a backup tool to back up the existing database, such as db_oms, to an SQL file such as db_oms_bak.sql before starting the upgrade. The new OMS image will run on the original db_oms database, and the database backup file such as db_oms_bak.sql can be used for rollback.

Considerations

If the SharePlex serialization method is used, when you upgrade from an earlier version to V4.0.2, an issue of incompatibility may occur due to the format change of trans.

Upgrade process

1. If high availability (HA) is enabled, disable it first.

2. Back up the databases.

3. Load the downloaded OMS installation package to the local image repository of the Docker container.

4. Start the container of OMS V4.0.2.

   The MetaDB for the container of OMS V4.0.2 must be the same as the MetaDB before the upgrade. In addition, the three disk mounting paths must be the same as those before the upgrade.

5. Go to the new container.

6. (Optional) After the cluster management (CM) and Supervisor services are started, execute the upgrade package in the .jar format.

   Note

   If you are upgrading OMS from V4.0.1 or V4.0.1 BP1 to 4.0.2, you do not need to perform this step.

7. Perform metadata initialization in the root directory.

8. After the docker_init.sh script is executed, confirm whether the server list is normal and whether all servers are in the Online state.

9. On the System Parameters page, enable HA, and configure the parameters.

   The following table shows the changes in components after HA is enabled.

   Project type	Project/Component status before upgrade	After upgrade (HA disabled)	After upgrade (HA enabled)
   Data migration project	The project and components run normally.	The project runs normally. Exceptions occur in the Store and JDBCWriter components.	If you upgrade OMS from a version earlier than V3.1.0, you need to manually restart the Store component or create a new store. In OMS V3.1.0 or later, data is pulled from the Store component at the interval specified by the refetchStoreIntervalMin parameter in ha.config to create new stores. The default interval is 30 minutes. JDBCWriter is automatically started.
   Data migration project	The project failed.	The project failed. Exceptions occur in the Store and JDBCWriter components.	If you upgrade OMS from a version earlier than V3.1.0, you need to manually restart the Store component or create a new store. In OMS V3.1.0 or later, data is pulled from the Store component at the interval specified by the refetchStoreIntervalMin parameter in ha.config to create new stores. The default interval is 30 minutes. JDBCWriter is automatically started. You must manually restore the project.
   Data synchronization project	The project and components run normally.	The project runs normally. Exceptions occur in the Store and Connector components.	Data is pulled from the Store component at the interval specified by the refetchStoreIntervalMin parameter. The default interval is 30 minutes. The Connector component is restarted.
   Data synchronization project	The project is suspended. The Connector component is suspended. The Store component runs normally.	The project is suspended. The Connector component is suspended. The store component becomes abnormal.	Data is pulled from the Store component at the interval specified by the refetchStoreIntervalMin parameter. The default interval is 30 minutes. The Connector component is restarted. You must manually restore the project.

10. Optional. Perform the rollback operation as needed.

11. After the upgrade is complete, clear the browser cache before you log on to OMS.

Limitations

• OMS V3.2.1 and later can be directly upgraded to OMS V4.0.2. If you use OMS of a version earlier than V3.2.1, you must upgrade it to V3.2.1 first.

• Before you start the upgrade, make sure that data is synchronized in quasi-real-time between the source and destination in data migration and synchronization projects created by using an earlier version of OMS, and that the forward switchover of the projects is completed. We do not recommend that you use the new version of OMS to perform the forward switchover.

• Before you upgrade OMS V3.2.1 or V3.2.2, if DDL synchronization is involved, you need to add the dbType parameter for the Connector component. Otherwise, the data synchronization projects cannot run. You must fix the issue after the upgrade. For more information, see What do I do to resolve compatibility issues when I upgrade OMS V3.2.1 or V3.2.2 to V4.0.2?

  Notice

  If you use OMS V3.3.0 and it contains data synchronization projects created in OMS V3.2.1 or V3.2.2, the preceding issue may occur. You can fix it by using the same methods.

  You can check whether the dbType or db_type parameter exists in the source configuration file of the Incr-Sync component. If any of the two parameters exists, no fix is required.