By default, Ansible parallelises tasks on multiple hosts simultaneously and speeds up automation in large inventories. But sometimes, this is not ideal in a load-balanced environment, where upgrading the servers simultaneously may cause the loss of services. How do we use Ansible to run the updates at different times? I use the keyword “serial” before executing the roles universal package.

- hosts: standalone_nodes
  become: yes
  serial: 1 
  roles:
        - linux_workstation

Alternatively, you can use percentages to indicate how many will upgrade at one time.

- hosts: standalone_nodes
  become: yes
  serial: 25%
  roles:
        - linux_workstation

References:

1. How to implement parallelism and rolling updates in Ansible