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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.

Thoughts?

Chris