openstack/kolla-ansible
Code Issues Proposed changes

RabbitMQ: Support setting ha-promote-on-shutdown

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By default ha-promote-on-shutdown=when-synced. However we are seeing
issues with RabbitMQ automatically recovering when nodes are restarted.
https://www.rabbitmq.com/ha.html#cluster-shutdown

Rather than waiting for operator interventions, it is better we allow
recovery to happen, even if that means we may loose some messages.
A few failed and timed out operations is better than a totaly broken
cloud. This is achieved using ha-promote-on-shutdown=always.

Note, when a node failure is detected, this is already the default
behaviour from 3.7.5 onwards:
https://www.rabbitmq.com/ha.html#promoting-unsynchronised-mirrors

This patch adds the option to change the ha-promote-on-shutdown
definition, using the flag `rabbitmq_ha_promote_on_shutdown`. This
value is unset by default to avoid any unexpected changes to the
RabbitMQ definitions.json file, as that would trigger an unexpected
restart of RabbitMQ during the next deploy.

Related-Bug: #1954925

Change-Id: I2146bda2c72ddac2c9923c6941b0596395fd9ab5
This commit is contained in:
John Garbutt 2021-12-17 16:20:32 +00:00 committed by Matt Crees
parent ef49c7440f
commit 94f3ce0c78
3 changed files with 20 additions and 2 deletions
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5
ansible/roles/rabbitmq/defaults/main.yml
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@ -84,6 +84,11 @@ rabbitmq_server_additional_erl_args: "+S 2:2 +sbwt none +sbwtdcpu none +sbwtdio
rabbitmq_tls_options: {}
# To avoid split-brain
rabbitmq_cluster_partition_handling: "pause_minority"
# For consistency use "when-synced", for availability use "always"
# The rabbitmq default for ha queues is "when-synced"
# More details see:
# https://www.rabbitmq.com/ha.html#promoting-unsynchronised-mirrors
rabbitmq_ha_promote_on_shutdown:
rabbitmq_extra_config: {}
####################

4
ansible/roles/rabbitmq/templates/definitions.json.j2
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@ -18,8 +18,8 @@
],
{% if om_enable_rabbitmq_high_availability | bool %}
"policies":[
{"vhost": "/", "name": "ha-all", "pattern": "^(?!(amq\\.)|(.*_fanout_)|(reply_)).*", "apply-to": "all", "definition": {"ha-mode":"all"}, "priority":0}{% if project_name == 'outward_rabbitmq' %},
{"vhost": "{{ murano_agent_rabbitmq_vhost }}", "name": "ha-all", "pattern": "^(?!(amq\\.)|(.*_fanout_)|(reply_)).*", "apply-to": "all", "definition": {"ha-mode":"all"}, "priority":0}
{"vhost": "/", "name": "ha-all", "pattern": "^(?!(amq\\.)|(.*_fanout_)|(reply_)).*", "apply-to": "all", "definition": {"ha-mode":"all"{% if rabbitmq_ha_promote_on_shutdown is not none %},"ha-promote-on-shutdown":"{{ rabbitmq_ha_promote_on_shutdown }}"{% endif %}}, "priority":0}{% if project_name == 'outward_rabbitmq' %},
{"vhost": "{{ murano_agent_rabbitmq_vhost }}", "name": "ha-all", "pattern": "^(?!(amq\\.)|(.*_fanout_)|(reply_)).*", "apply-to": "all", "definition": {"ha-mode":"all"{% if rabbitmq_ha_promote_on_shutdown is not none %},"ha-promote-on-shutdown":"{{ rabbitmq_ha_promote_on_shutdown }}"{% endif %}}, "priority":0}
{% endif %}
]
{% else %}

13
releasenotes/notes/rabbitmq-ha-promote-on-shutdown-9099c6643f2d0cce.yaml Normal file
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@ -0,0 +1,13 @@
---
features:
- |
The config option `rabbitmq_ha_promote_on_shutdown` has been added, which
allows changing the RabbitMQ definition `ha-promote-on-shutdown`. By
default `ha-promote-on-shutdown` is "when-synced". We recommend changing
this to be "always". This basically means we don't mind losing some
messages, instead we give priority to rabbitmq availability. This is most
relevant when restarting rabbitmq, such as when upgrading. Note that
setting the value of this flag, even to the default value of "when-synced",
will cause RabbitMQ to be restarted on the next deploy.
For more details please see:
https://www.rabbitmq.com/ha.html#cluster-shutdown