Re: [PATCH ha-manager 7/7] manager: try multiple priority classes when applying negative resource affinity

["Michael Köppl" <m.koeppl@proxmox.com>]

On Wed Apr 22, 2026 at 12:00 PM CEST, Daniel Kral wrote:

[snip]

> @@ -354,7 +363,15 @@ sub select_service_node {
>          }
>      }
>  
> -    apply_negative_resource_affinity($separate, $pri_nodes);
> +    # do not consider nodes where HA resources from a possible negative resource
> +    # affinity rule are running on.
> +    # as such a negative resource affinity could end up emptying the current
> +    # priority class, try the succeeding priority classes which result in a
> +    # non-empty node set or else end up with an empty set.
> +    do {
> +        apply_negative_resource_affinity($separate, $pri_nodes);
> +    } while (keys %$pri_nodes < 1 && ($pri_nodes = shift @$priority_classes));
> +    $pri_nodes = {} if !defined($pri_nodes);

Just above this, $tried_nodes is removed from $pri_nodes. If the
$tried_nodes are not also removed from other priority classes, couldn't
this run into a migration loop where it tries again and again to migrate
to a failed node from a lower priority class? I'm not entirely sure
about this, it just seemed a bit odd to me at first glance. The only
scenario I can think of is one where you have vm:100, vm:101 with a
non-strict node affinity rule for vm:100 (so you'd have 2 priority
classes. don't think it's possible otherwise because you cannot combine
negative resource affinity rule and node affinity rule with priorities.)
and a negative resource affinity rule that keeps vm:100 and vm:101 apart
and then migrating vm:100 to the other available node (one not in the
node affinity rule, so with prio -1 and therefore lower prio class)
fails.

>  
>      # fallback to the previous maintenance node if it is available again.
>      #
> diff --git a/src/test/test-resource-affinity-with-node-affinity-maintenance-strict-negative1/README b/src/test/test-resource-affinity-with-node-affinity-maintenance-strict-negative1/README
> index c6a11cec..e1fc0d04 100644
> --- a/src/test/test-resource-affinity-with-node-affinity-maintenance-strict-negative1/README
> +++ b/src/test/test-resource-affinity-with-node-affinity-maintenance-strict-negative1/README
> @@ -4,5 +4,6 @@
>  - in a non-strict node affinity rule to node2 and node3 (equal priority), and
>  - in a strict negative resource affinity rule with each other.

[snip]