Hello @Sangwoo Lee​ ,

As mentioned by vignesh, it seems like an infra related issue.

> Does the user (which executes the job) has access to start a cluster?

> Incase if it is not an access issue and Incase if you are starting a lot of workflow jobs together at the same time, try scheduling one job 5 minutes earlier ( just to start the cluster) - and schedule the remaining jobs to start together after 5 minutes. Idea is to have the cluster available already when the majority of the jobs need it.