add documentation about any_errors_fatal

This commit is contained in:
daburmistrov 2015-07-30 12:16:55 +03:00 committed by Dmitry Burmistrov
parent b37be236d9
commit 0b277b43a4

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@ -185,6 +185,50 @@ use the default remote connection type::
- hosts: 127.0.0.1
connection: local
.. _interrupt_execution_on_any_error:
Interrupt execution on any error
````````````````````````````````
With option ''any_errors_fatal'' any failure on any host in a multi-host play will be treated as fatal and Ansible will exit immediately without waiting for the other hosts.
This option is used when ''serial'' keyword is used. But sometimes ''serial'' execution is unsuitable - number of hosts is unpredictable (because of dynamic inventory), speed is crucial (simultaneous execution is required). But all tasks must be 100% successful to continue playbook execution.
For example there is a service located in many datacenters, there a some load balancers to pass traffic from users to service. There is a deploy playbook to upgrade service deb-packages. Playbook stages:
- disable traffic on load balancers (must be turned off simultaneously)
- gracefully stop service
- upgrade software (this step includes tests and starting service)
- enable traffic on load balancers (should be turned off simultaneously)
Service can't be stopped with "alive" load balancers, they must be disabled, all of them. So second stage can't be played if any server failed on "stage 1".
For datacenter "A" playbook can be written this way::
---
- hosts: load_balancers_dc_a
any_errors_fatal: True
tasks:
- name: 'shutting down datacenter [ A ]'
command: /usr/bin/disable-dc
- hosts: frontends_dc_a
serial: '100%'
max_fail_percentage: 19
tasks:
- name: 'stopping service'
command: /usr/bin/stop-software
- name: 'updating software'
command: /usr/bin/upgrade-software
- hosts: load_balancers_dc_a
tasks:
- name: 'Starting datacenter [ A ]'
command: /usr/bin/enable-dc
In this example Ansible will start software upgrade on frontends only if all load balancers are successfully disabled.
.. seealso::
:doc:`playbooks`