[Labs-l] Instance scheduler modified, could cause instance creation to fail

[Ryan Lane]

This did indeed break things. I upped the max_cores option to 80. Soon
enough, all hosts will reach this and we'll no longer be able to
create instances. When we get the new hardware in, we'll be able to
create new ones again.

Note: 80 cores per host is roughly 40-60 instances, depending on the
type of instances created.

On Wed, Feb 22, 2012 at 4:44 PM, Ryan Lane <rlane32 at gmail.com> wrote:
> I've switched from using the chance scheduler to the simple scheduler
> for nova (https://gerrit.wikimedia.org/r/#change,2731). This means
> that when instances are created, the compute node with the least
> number of instances running will be chosen, rather than before where
> any random compute node was chosen.
>
> The new scheduler has some options which limit which nodes are chosen,
> though, and the defaults may be set a little low. If you create an
> instance and it stays in the scheduling or pending mode forever (or it
> eventually fails), let me know and I'll tweak the configuration
> options.
>
> - Ryan