Open Stack

On Tue, 2022-07-19 at 13:51 +0100, A Monster wrote:
> I've deployed openstack xena using *kolla-ansible* on *centos 8 stream*,
> I've used multiple controller nodes, a bunch of compute nodes and a storage
> cluster.
> Controller nodes include network services.
> 
> I want to know how can I successfully set up redundancy between these
> controller nodes, in a way that some nodes are active while others are on
> standby state, and would only become active in case when the active nodes
> are to fail.
in generall that is not needed with openstack.

most service are partly or mostly stateless using the db to store any relevent persitent state.

that generally menas that for example you can have n nova api process active at any time and
you do not need to use external managment fo the serivce to have some be active and other be passive.

in general such active/standby configurtation is an antipatter and should not need to be done with openstack.

in kolla keepalived and haproxe shoudl migrate the contol plane vips and include/exclude donw services automaiticaly.

if you want to manually take over that function its likely possibel but not how HA is intended to work in general.

i dont work on kolla anymore so perhapse there perspectiive has change but in generaly i would advocat for active active
ha in preference ot active standby.
> 
> Thank you. Regards