Can I Perform Online Migration Without Any Service Interruption?¶
Yes. You can use the application dual-write mode. In this mode, during data migration, data is still read from the source Redis instance, and operations such as adding, deleting, and modifying data are also performed on the DCS Redis instance.
After maintaining the preceding mode for a period of time (waiting for a large amount of data to be deleted after expiration), migrate the cached data from your service systems to DCS. If service system migration to the cloud service is also involved, deploy your service systems before migrating your cached data.
This mode is not recommended for the following reasons:
Stable and quick network access cannot be ensured. If the source Redis instance is not deployed on DCS, access DCS over a public network, which is inefficient.
Modify the code to implement concurrent writing of two sets of data.
The data eviction policy varies depending on the source Redis instance. It may take a long time to complete data migration and it is difficult to ensure data integrity.