OpenStack Liberty Release Notes

OpenStack Networking (Neutron)

If you are coming from Kilo stable, please make sure you have fully upgraded to the latest release of that lineage before deploying Liberty. Due to bug https://bugs.launchpad.net/nova/+bug/1474074 versions of Kilo from before the fix will be problematic when talking to Liberty nodes.
Allocation ratios for RAM and CPU are now defined within the nova-compute service (so per compute node), thus need to be also provided for the scheduler service. Depending on whether a compute node is running Kilo or Liberty, the allocation ratios will behave differently : if the compute node is running Kilo then the CPU and RAM allocation ratios for that compute node will be the ones defaulted in the controller's nova.conf file.Or, if the compute node is Liberty then you'll be able to set a per-compute allocation ratio for both CPU and RAM. To be removed in case https://review.openstack.org/#/c/216696/ is not merged for Liberty (bauzas, 2015/08/26)
nova-compute should be upgraded to Liberty code before upgrading Neutron services per the new "network-vif-deleted" event: https://review.openstack.org/#/c/187871/

The name of some middleware used by ceilometer changed in a backwards-incompatible way. Before upgrading, edit the paste.ini file for ceilometer to change "oslo.middleware" to "oslo_middleware". For example using sed -ri 's/oslo\.middleware/oslo_middleware/' api_paste.ini