delayed_job there is already one or more instance(s) of the program running code example

Example: delayed_job there is already one or more instance(s) of the program running

## For Issues
-> there is already one or more instance(s) of the program running.
->  `kill': Operation not permitted (Errno::EPERM)

## This command resolved my issue.

RAILS_ENV=production script/delayed_job -n 2 --pid-dir=tmp/pids restart