Comment 15 for bug 1513144

Just to make sure we are all on the same page.

* Today Neutron provides automatic failover for both L3 and DHCP agents whose admin status is up [1, 2].
* As an operator, I can disable the automatic failover if I want to implement some out-of-band failover mechanism.
* If I set admin_status to DOWN, the agent is ignored, regardless of the failover mechanism
* We have an 'alive' flag associated to agents, but this is dynamically set based on the last heartbeat.

Carlos, you said and I quote you:

[..Such action requires a new API exposed by Neutron allowing admins to set (true/false) the aliveness state of Neutron agents..]

The 'alive' cannot be overriden by the admin, because it means: the neutron agent (whichever it may be) is alive and kicking. If you want to mark an agent as down, that's what admin_status is for.

[1] https://github.com/openstack/neutron/blob/master/etc/neutron.conf#L243
[2] https://github.com/openstack/neutron/blob/master/etc/neutron.conf#L238