DVR HA not enabled by default

[Federico Iezzi]

With OpenStack Mitaka Neutron supports router in DVR mode with HA for the SNAT.
In the template, this feature has been disabled.
https://review.openstack.org/#/c/359969/

Link to DVR-HA blueprint
https://blueprints.launchpad.net/neutron/+spec/improve-dvr-l3-agent-binding

DVR-HA review
https://review.openstack.org/#/c/143169/

Link to Neutron unit tests for DVR-HA
https://github.com/openstack/neutron/blob/master/neutron/tests/functional/services/l3_router/test_l3_dvr_ha_router_plugin.py#L372

During the Neutron Newton-rc1 development cycle, a number of DVR-related issues have been fixed. Two of them were related to the SNAT.

https://bugs.launchpad.net/neutron/+bug/1602614
https://bugs.launchpad.net/neutron/+bug/1607381

You should consider re-enabling the DVR-HA since it is a critical piece and until Mitaka this was the major DVR's drawback.

[Brent Eagles (beagles)]

Please note that it can still be enabled by setting EnableL3HA to true in Newton. There isn't really anything that prevents a user from doing so. The THT logic for handling enabling L3 HA if the controller count > 1 was added in newton to address backwards compatibility concerns as that logic has been moved out of the tripleo client. We will be revisiting how tripleo addresses HA configuration for neutron in Ocata. Whether L3 HA, DVR or otherwise will be enabled by default is yet to be decided.

[Assaf Muller (amuller)]

I would not recommending using DVR and HA without https://review.openstack.org/#/c/255237/, which was merged in Newton and is not currently available in Mitaka.

[Federico Iezzi (fiezzi)]

@Assaf Muller: appreciate your comment but the "l2pop fdb flows for HA router ports" is an L3HA enhancement which does not depend on the DVR

[Brent Eagles (beagles)]

There are apparently remaining issues with DVR and HA coexistence so we might want to push this off until we are certain that all is well

[Emilien Macchi (emilienm)]

There are no currently open reviews on this bug, changing the status back to the previous state and unassigning. If there are active reviews related to this bug, please include links in comments.

[Brent Eagles (beagles)]

We don't plan on enabling this for ML2/OVS at this time.