---
- hosts:
    - lb
    - worker
    - db
  roles:
    - webcluster-base

- hosts: lb
  serial: "25%"
  max_fail_percentage: 40
  roles:
    - keepalived-simple
    - webcluster-haproxy

- hosts: worker
  serial: 2
  max_fail_percentage: 20
  roles:
    - webcluster-worker
    - apache2-backend-mod_remoteip

- hosts: db
  serial: 1
  max_fail_percentage: 10
  roles:
    - mariadb-galera
    - webcluster-db