Dear all,
One of the discussions at the PTG in Denver raised the need for a mechanism to take ironic nodes out of production (a task for which the currently available 'maintenance' flag does not seem appropriate [1]).
The use case there is an unhealthy physical node in state 'active', i.e. associated with an instance. The request is then to enable an admin to mark such a node as 'faulty' or 'in quarantine' with the aim of not returning the node to the pool of available nodes once the hosted instance is deleted.
A very similar use case which came up independently is node retirement: it should be possible to mark nodes ('active' or not) as being 'up for retirement' to prepare the eventual removal from ironic. As in the example above, ('active') nodes marked this way should not become eligible for instance scheduling again, but automatic cleaning, for instance, should still be possible.
In an effort to cover these use cases by a more general "quarantine/retirement" feature:
- are there additional use cases which could profit from such a "take a node out of service" mechanism?
- would these use cases put additional constraints on how the feature should look like (e.g.: "should not prevent cleaning")
- are there other characteristics such a feature should have (e.g.: "finding these nodes should be supported by the cli")
Let me know if you have any thoughts on this.
Cheers, Arne
[1] https://etherpad.openstack.org/p/DEN-train-ironic-ptg, l. 360