Instance don't recover on same segment

[Khoi]

Hello.
I am using openstack xena by kolla ansible deployment.

My scenario is:

Segment A:
 compute01
 compute02
 compute03

Segment B:
 compute04
 compute05

When I turn off compute01, I hope that instance will recover on compute02 or compute03 but it recovered on segment B.

I use auto as recovery method on 2 segments.

I feel strange.

Thank you.