使用命令查看当前支持的strategy 列表及其描述
ansible-doc -t strategy -l
debug Executes tasks in interactive debug session
free Executes tasks without waiting for all hosts
host_pinned Executes tasks on each host without interruption
linear Executes tasks in a linear fashion is default
liner 每个task 顺序执行，例如fork=5 我们有10个主机需要执行当前playbook 那么只能10个主机都执行了task1 之后才会往下走新的任务