---
- name: Long running job test
  hosts: all
  gather_facts: no
  become: no


  vars:
    time_to_sleep : 300
    run_cmd       : "find /"
    poll_interval : 3


  tasks:
    - name: Simulate a long running job
      command : "{{ run_cmd }}"
      async   : "{{ time_to_sleep + 10 }}" # give +10s leeway
      poll    : "{{ poll_interval }}"


...