openstack
/
kolla-ansible
Code Issues Proposed changes

Add way to change weight of haproxy backend per service 

This patch adding option to control weight of haproxy
backends per service via host variable.

Example:

[control]
server1 haproxy_nova_api_weight=10
server2 haproxy_nova_api_weight=2 haproxy_keystone_internal_weight=10
server3 haproxy_keystone_admin_weight=50

If weight is not defined, everything is working as before.

Change-Id: Ie8cc228198651c57f8ffe3eb060875e45d1f0700
This commit is contained in:
Michal Arbet 2021-02-15 14:14:31 +01:00
parent 18fd27feff
commit 7c2b4bead2
3 changed files with 33 additions and 1 deletions
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7
ansible/roles/haproxy-config/templates/haproxy_single_service_split.cfg.j2
View File

@ -93,7 +93,12 @@ backend {{ service_name }}_back
{% for host in groups[host_group] %}
{% set host_name = hostvars[host]['ansible_hostname'] %}
{% set host_ip = 'api' | kolla_address(host) %}
server {{ host_name }} {{ host_ip }}:{{ listen_port }} {{ haproxy_health_check_final }} {{ backend_tls_info }}
{% set service_weight = 'haproxy_' + service_name + '_weight' %}
{% set backend_weight_info = '' %}
{% if hostvars[host][service_weight] is defined and hostvars[host][service_weight] | int != 0 and hostvars[host][service_weight] <= 256 %}
{% set backend_weight_info = 'weight %s'|format(hostvars[host][service_weight]) %}
{% endif %}
server {{ host_name }} {{ host_ip }}:{{ listen_port }} {{ haproxy_health_check_final }} {{ backend_tls_info }} {{ backend_weight_info }}
{% endfor %}
{% endif %}
{% endmacro %}

17
doc/source/reference/high-availability/haproxy-guide.rst
View File

@ -45,3 +45,20 @@ This is especially helpful for connections to MariaDB. See
`here <https://blog.cloudflare.com/when-tcp-sockets-refuse-to-die/>`__ and
`here <https://access.redhat.com/solutions/726753>`__ for
further information about this kernel option.
Backend weights
---------------
When different baremetal are used in infrastructure as haproxy backends
or they are overloaded for some reason, kolla-ansible is able to change
weight of backend per sevice. Weight can be any integer value from 1 to
256.
To set weight of backend per service, modify inventory file as below:
.. code-block:: ini
[control]
server1 haproxy_nova_api_weight=10
server2 haproxy_nova_api_weight=2 haproxy_keystone_internal_weight=10
server3 haproxy_keystone_admin_weight=50

10
releasenotes/notes/haproxy-service-backend-weight-e4a908f732a37b42.yaml Normal file
View File

@ -0,0 +1,10 @@
---
features:
- |
The haproxy-config role now allows user to set weight per
haproxy's backend. This can be achieved by setting a hostvar
``haproxy_{{ service }}_weight`` in inventory file to any integer
value in range from 1 to 256, so the higher the weight, the higher
the load. This can be set per ``{{ service }}``. If hostvar is not
specified, backend's weight is not rendered in final haproxy
configuration.