Open Stack

On 09/15/2014 11:26 PM, Chris wrote:
> Hello,
>
> We have a OpenStack setup with a large number of compute nodes spread in
> different subnets which are represented as different physnet’s in OpenStack.
>
> When we start an instance we see that the scheduler choose a compute
> node and tries to spawn the instance, then it sees its not in the right
> physnet and choose a different compute node.

How would the scheduler know which compute node is "in the right 
physnet"? In other words, when an instance is launched, how does the 
scheduler know what is the "correct physnet" for that type of instance?

> In our case this takes around 4 – 10 attempts. All this attempts counts
> for the “scheduler_max_attempts” which default value is 3. We increase
> this value to prevent errors, but it’s still very inefficient especially
> in a large environment.
>
> Is there a way that the scheduler knows the physnet/subnet position of
> the compute nodes before the instance tries to spawn?