Open Stack

On Tue, Sep 9, 2014 at 2:19 PM, Mike Scherbakov
<mscherbakov at mirantis.com> wrote:
>> On Tue, Sep 9, 2014 at 6:02 PM, Clint Byrum <clint at fewbar.com> wrote:
> The idea is not simply deny or hang requests from clients, but provide them
> "we are in maintenance mode, retry in X seconds"
>
>> You probably would want 'nova host-servers-migrate <host>'
> yeah for migrations - but as far as I understand, it doesn't help with
> disabling this host in scheduler - there is can be a chance that some
> workloads will be scheduled to the host.

Regarding putting a compute host in maintenance mode using "nova
host-update --maintenance enable", it looks like the blueprint and
associated commits were abandoned a year and a half ago:
https://blueprints.launchpad.net/nova/+spec/host-maintenance

It seems that "nova service-disable <host> nova-compute" effectively
prevents the scheduler from trying to send new work there.  Is this
the best approach to use right now if you want to pull a compute host
out of an environment before migrating VMs off?

I agree with Tim and Mike that having something respond "down for
maintenance" rather than ignore or hang would be really valuable.  But
it also looks like that hasn't gotten much traction in the past -
anyone feel like they'd be in support of reviving the notion of
"maintenance mode"?

-Christopher