Strange error for ScheduleTask after server-master restart

[lance6716]

What did you do?

https://github.com/pingcap/tiflow/pull/7091

What did you expect to see?

no error

What did you see instead?

server-master-2              | 2022-09-16T07:20:21.557253508Z [2022/09/16 07:20:21.556 +00:00] [WARN] [worker_creator.go:114] ["ScheduleTask returned error"] [job_id=dataflow-engine-job-manager] [error="CapacityNotEnoughError: {\"FinalCandidates\":[]}\ ...

Versions of the cluster

Dataflow Engine version (run tiflow version):

(paste Dataflow Engine version here)

[lance6716]

docker_compose.log

[lance6716]

cc @maxshuang