edee94d4f0
Instead of using a custom 'FORKS' parameter, this patch switches to using the standard Ansible environment variable 'ANSIBLE_FORKS'. The patch also updates the documentation related to forks to use the right parameter and also to give better examples. Change-Id: I7fcf152ee945c17bd8c9f6d4ff111805e9e2d0b8
1.8 KiB
Home OpenStack-Ansible Installation Guide
Appendix D: Tips and tricks
Ansible forks
The default MaxSessions setting for the OpenSSH Daemon is 10. Each Ansible fork makes use of a Session. By default, Ansible sets the number of forks to 5. However, you can increase the number of forks used in order to improve deployment performance in large environments.
Note that a number of forks larger than 10 will cause issues for any
playbooks which make use of delegate_to or
local_action in the tasks. It is recommended that the
number of forks are not raised when executing against the Control Plane,
as this is where delegation is most often used.
The number of forks used may be changed on a permanent basis by
including the appropriate change to the ANSIBLE_FORKS in
your .bashrc file. Alternatively it can be changed for a
particular playbook execution by using the --forks CLI
parameter. For example, the following executes the nova playbook against
the control plane with 10 forks, then against the compute nodes with 50
forks.
# openstack-ansible --forks 10 os-nova-install.yml --limit compute_containers
# openstack-ansible --forks 50 os-nova-install.yml --limit compute_hostsFor more information about forks, please see the following references:
- OpenStack-Ansible Bug 1479812
- Ansible forks entry for ansible.cfg
- Ansible Performance Tuning