This error indicates that the upstream binlog position recorded in the metadata file output by the dump unit has been purged during the full migration.
If this issue occurs, you need to pause the task, delete all migrated data in the downstream database, and start a new task with the
You can avoid this issue in advance by configuring in the following ways:
- Increase the value of
expire_logs_daysin the upstream MySQL database to avoid wrongly purging needed binlog files before the full migration task completes. If the data volume is large, it is recommended to use dumpling and TiDB-Lightning at the same time to speed up the task.
- Enable the relay log feature for this task so that DM can read data from relay logs even though the binlog position is purged.