Comment 3 for bug 959356

Hi,

I am fully agree with the serious performance issue concerning the network node in case of large number of instances.
Nevertheless ignoring "old" dhcp lease from dnsmasq seems to be the wrong way to correct this issue, and is dangerous.
In case of renew DHCP request (DHCPREQUEST with src IP address) Dnsmasq never launch nova-dhcpbridge script with "add" argument but with "old" one.
Hence lease_fixed_ip will not be run and fixed_ip "updated_at" and "lease" fields will never be updated in database.
Consequently the periodic task calling "fixed_ip_disassociate_all_by_timeout" can disassociate the fixed ip even if DHCP renew was sent by the VM and so fresh disassociate IP can be reuse badly for another VM.