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Hey folks, sorry if this is a jejune question, but:

In a no-reschedules-by-nova world, if a deploy fails on host 1, how does
the orchestrator (whatever that may be) ask nova to deploy in such a way
that it'll still try to find a good host, but *avoid* host 1?  If host 1
was an attractive candidate the first time around, wouldn't it be likely
to remain high on the list the second time?

I'd also like to second the thought that the monolithic "instance in
error state" gives the orchestrator no hint as to whether the deploy
failed because of something the orchestrator did (remedy may be to
redrive with different inputs, but no need to exclude the original
target host) versus because something went wrong on the compute host
(remedy would be to retry on a different host with the same inputs).
Kind of analogous to the difference between HTTP 4xx and 5xx error
classes.  (Perhaps implying a design whereby the nova API responds to
the deploy request with different error codes accordingly.)

Thanks,
efried
.