#openstack-meeting-cp: cinder-nova-api-changes

Meeting summary

1. 1. we are trying to figure out whether to go with v1 or v2 (ildikov, 17:07:32)
   2. it would be great having a more simpler approach (ildikov, 17:09:11)
   3. reserve call remains as is (ildikov, 17:13:17)
   4. it helps avoid races with multiple attach calls, etc. (ildikov, 17:13:44)
   5. should we have a reserve that creates an attachment_id? (ildikov, 17:15:26)
   6. the old or new version of the reserve call will get the instance_uuid as the Nova side has that the earliest (ildikov, 17:17:34)
   7. in the new and shiny version of the proposal reserve will create the attachment record in Cinder and return the id (ildikov, 17:19:03)
   8. regarding v1 and v2 John Garbutt thinks we need all the v2 calls (ildikov, 17:19:47)
   9. Nova can store additional info and handle locks to not have an attach, while we're detaching (ildikov, 17:24:44)
   10. we need to shorten the window and have locks to eliminate races (ildikov, 17:27:51)
   11. Cinder returns info about either safe to detach or the info about the driver whether it shares connection or not (ildikov, 17:28:35)
   12. locking needs to be done on Nova side, Nova gets all the info from Cinder that's needed (ildikov, 17:47:08)
   13. if we have create_attachment, update_attachment and remove_attachment, we should not have reserve, let create handle the lock on Cinder side (ildikov, 17:49:10)
   14. one attach at a time even in case of multiattach just to be safe (ildikov, 17:49:52)
   15. after create, Nova sends the connection info to Cinder (ildikov, 17:50:51)
   16. Cinder returns the info about shared or not shared connection, so Nova has the info for disconnect (ildikov, 17:51:29)
   17. do not remove attachment from Cinder before disconnect (ildikov, 17:51:48)
   18. Nova removes the attachments and calls disconnect when no further attachments remained (ildikov, 17:53:35)
   19. live migrate: same instance_uuid but different hosts is enabled in Cinder (ildikov, 17:54:32)
   20. we need both connections at the same time for making live migrate work (ildikov, 17:54:59)
   21. John Garbutt works on live migrate flow and update the spec (ildikov, 18:07:33)
   22. John Griffith updates v2 with the agreements from today's call on create/delete/update attachment (ildikov, 18:08:17)
   23. Ildiko handles meeting minutes and administration (ildikov, 18:10:14)

Action items

1. (none)

People present (lines said)

1. ildikov (44)
2. hemna (7)
3. scottda (6)
4. smcginnis (5)
5. mriedem (4)
6. openstack (3)
7. johnthetubaguy (3)
8. jgriffith (2)