Hi, I'm currently working on solving Nova-Neutron issues during Live Migration. This mail is intended to raise awareness cross project and get things kicked off.
The issues ========== #1 When portbinding fails, instance is migrated but stuck in error state #2 Macvtap agent live Migration when source and target use different physical_interface_mapping [3]. Either the migration fails (good case) or it would place the instance on a wrong network (worst case) #3 (more a feature): Migration cross l2 agent not possible (e.g. migrate from lb host to ovs host, or from ovs-hybrid to new ovsfirewall host) The proposal ============ All those problems could be solved with the same approach . The proposal is, to bind a port to the source AND to the target port during migration. * Neutron would need to allow multiple bindings for a compute port and externalize that via API. - Neutron Spec [1] - Bug [4] is a prereq to the spec. * Nova would need to use those new APIs to check in pre_live_migration, if the binding for target host is valid and to modify the instance definition (e.g. domain.xml) during migration. - Nova Spec [2] This would solve the issues in the following way: #1 would abort the migration before it started, so instance is still usable #2 Migration is possible with all configurations #3 would allow such a migration Coordination ============ Some coordination between Nova & Neutron is required. Along todays Nova Live Migration Meeting [5] this will happen on the Nova midcycle. I put an item on the agenda [6]. Would be great that anybody that is interested in this bugfix/feature could comment on the specs [1] or [2] to get as much feedback as possible before the nova midcycle in July! Thank you! [1] Neutron spec: https://review.openstack.org/#/c/309416 [2] Nova spec: https://review.openstack.org/301090 [3] macvtap bug: https://bugs.launchpad.net/neutron/+bug/1550400 [4] https://bugs.launchpad.net/neutron/+bug/1367391 [5] http://eavesdrop.openstack.org/meetings/nova_live_migration/2016/nova_live_migration.2016-06-28-14.00.log.html [6] https://etherpad.openstack.org/p/nova-newton-midcycle andreas_s __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
