What Are the Common Causes of Redis Migration Failures?

Check if a master/standby switchover occurred during the migration. If it occurred, contact technical support to temporarily disable master/standby switchover until the migration completes.
For online migration, check whether the SYNC and PSYNC commands are disabled on the source Redis instance. If they are disabled, enable them to allow data synchronization.
By default, a Proxy Cluster instance has only one database (DB 0). Before you migrate data from a single-node or master/standby instance to a Proxy Cluster instance, check whether any data exists on databases other than DB 0. If yes, enable multi-DB for the Proxy Cluster instance by referring to Enabling Multi-DB.
By default, a Redis Cluster instance has only one DB (DB 0). Before you migrate data from a single-node or master/standby instance to a Redis Cluster instance, check whether any data exists on databases other than DB 0. To ensure that the migration succeeds, move all data to DB 0 by referring to Online Migration from Another Cloud Using Rump.