Selective topology distribution will not fetch reachable objects of other tenants

[Dima Kuznetsov]

Dragonflow supports selective topology distribution, a feature to control what parts of northbound database each controller will fetch.

When it is off, each controller fetches all objects in the database, when it is on, it fetches only the topics of local ports.

The latter can run into problems when a packet needs to traverse networks of several tenants:

Consider:
 * a VM in tenant A
 * a router in tenant A
 * an external network in tenant B

The selective topology enabled controller will fetch tenant A objects, but will not have tenant B objects, making it impossible for tenant A's VM traffic to reach the external network.

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/496247

[Omer Anson (omer-anson)]

Bumped to medium. Won't make the Pike cutoff. Re-raise to High once Pike is tagged.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/496247
Committed: https://git.openstack.org/cgit/openstack/dragonflow/commit/?id=b541f03544fe4f8527c2b7288edcc7c30b75427a
Submitter: Jenkins
Branch: master

commit b541f03544fe4f8527c2b7288edcc7c30b75427a
Author: Omer Anson <email address hidden>
Date: Tue Aug 22 17:20:38 2017 +0300

    Disable Selective-Proactive Distribution by default

    Selective-Proactive Distribution is not working well. We disable it by
    default due to the many issues it causes.

    Change-Id: Ieec481dbf086a3fdf37077f8e15a4aa8365a967c
    Related-Bug: #1712266