Comment 2 for bug 1532809

Here's a lead on the gate-grenade-dsvm - http://paste.openstack.org/show/484637/

We "kill -HUP 21237" the dnsmasq and immediately issue a dhcp_release, you can see in syslog.txt that the HUP reaches dnsmasq while it is reloading. As a result screen-n-dhcp does not show a 'del' at all (nor is there a DHCPRELEASE in syslog)

In fact during the reload dnsmasq sends a 'old' to the dhcp script. So we probably have to wait for the reload to finish (sleep?) before we call dhcp_release.

Note that we can't switch order of HUP and release because it causes other problems :
http://git.openstack.org/cgit/openstack/nova/tree/nova/network/manager.py#n1048