all: 
  hosts: 
  children:
    master:
      hosts:
        compute000
      vars: 
        master_ip: 10.0.0.100
    compute:
      hosts:
        compute002:
        compute004:
        compute005:
    gpus:
      hosts:
        compute002:
        compute004:
        compute005:
    workers:
      children:
        compute:
        gpu: 
    cluster:
      children:
        master:
        workers: