[magnum] [kolla-ansible] [kayobe] [Victoria] Magnum Kubernetes cluster failure recovery

feilong feilong at catalystcloud.nz
Wed Aug 11 18:41:24 UTC 2021

Let me try to explain it from a design perspective:

1. Auto scaler: Now cluster auto scaler talks to Magnum resize API
directly to scale, see

2. Auto healer: As you know auto scaler only cares about the worker
node, it won't scale the master nodes. However, auto healer can repair
both master nodes and worker nodes. With worker nodes repairing, Magnum
auto healer uses magnum resize API. But because the magnum resize api
doesn't support master nodes resizing, so the master nodes repairing is
done by Heat stack update. magnum auto healer will mark some resources
of the master node as unhealthy, then call Heat stack update to rebuild
those resources.

On 11/08/21 10:25 pm, Sven Kieske wrote:
> On Mi, 2021-08-11 at 10:16 +0000, Sven Kieske wrote:
>> the problem is, that the kubernetes autoscaler directly talks to the openstack api, e.g.
>> nova for creating and destroying instances.
> Nevermind I got that wrong.
> The autoscaler talks to heat, so there should no problem (but heat trips itself up on some error conditions).
> I was in fact talking about the magnum auto healer (https://github.com/kubernetes/cloud-provider-openstack/blob/master/docs/magnum-auto-healer/using-magnum-auto-healer.md )
> which seems to circumvent heat and talks directly with nova.
> Are you using the magnum auto healing feature by chance?
Cheers & Best regards,
Feilong Wang (王飞龙) (he/him)
Head of Research & Development

Catalyst Cloud
Aotearoa's own

Mob: +64 21 0832 6348 | www.catalystcloud.nz
Level 6, 150 Willis Street, Wellington 6011, New Zealand

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