DM can't update task config for DDL

[lance6716]

What did you do?

use OpenAPI to update task configuration, which is related to DDL.

What did you expect to see?

DDL can use the new behaviour

What did you see instead?

DDL uses the old behaviour

Versions of the cluster

DM version (run dmctl -V or dm-worker -V or dm-master -V):

after v6.3.0

current status of DM cluster (execute query-status <task-name> in dmctl)

(paste current status of DM cluster here)

[lance6716]

This is because DDLWorker is only created in Syncer.Init. Syncer.Update will not create a new DDLWorker

https://github.com/pingcap/tiflow/blob/063e645c829ca95c5b35eeaf116dfdb0395193be/dm/syncer/syncer.go#L511

[GMHDBJD]

use stop-task and start-task as workaround

[seiya-annie]

/found customer