Open Stack

On 26 May 2015 at 03:37, Chris Friesen <chris.friesen at windriver.com> wrote:
>
> Hi all,
>
> I've just opened a bug around booting multiple instances at once, and it was
> suggested on IRC that I mention it here to broaden the discussion around the
> ideal behaviour.
>
> The bug is at:  https://bugs.launchpad.net/nova/+bug/1458122
>
> Basically the problem is this:
>
> When booting up instances, nova allows the user to specify a "min count" and
> a "max count".  So logically, this request should be considered successful
> if at least "min count" instances can be booted.
>
> Currently, if the user has quota space for "max count" instances, then nova
> will try to create them all. If any of them can't be scheduled, then the
> creation of all of them will be aborted and they will all be put into an
> error state.
>
> Arguably, if nova was able to schedule at least "min count" instances (which
> defaults to 1) then it should continue on with creating those instances that
> it was able to schedule. Only if nova cannot create at least "min count"
> instances should nova actually consider the request as failed.
>
> Also, I think that if nova can't schedule "max count" instances, but can
> schedule at least "min count" instances, then it shouldn't put the
> unscheduled ones into an error state--it should just delete them.

I think taking successfully provisioned vm's and rolling them back is
poor, when the users request was strictly met- I'm in favour of your
proposals.

-Rob

-- 
Robert Collins <rbtcollins at hp.com>
Distinguished Technologist
HP Converged Cloud