25->24 DB migration fails

[Rushi Agrawal]

See log: http://paste.openstack.org/show/110125/
Tried on a fresh devstack. No volumes, etc were created

[Jay Bryant (jsbryant)]

I have seen issues in the downgrade path as well but haven't been able to get a chance to further debug.

[Xing Yang (xing-yang)]

Looks like this has to do with 025_add_consistencygroup.py. I'll take a look.

[Rushi Agrawal (rushiagr)]

Any plans of including this in Juno RCs?

[Xing Yang (xing-yang)]

I would like to, but I'm still trying to repro this. I have an idea on how to fix this, but can't really validate it without reproducing it first.

[John Griffith (john-griffith)]

Until we get more details and the ability to reproduce this I'm marking as incomplete for now.

[Xing Yang (xing-yang)]

Reproduced this on a fresh devstack install.

Error from Rushi's output while running "cinder-manage db sync 24" from 25:
OperationalError: (OperationalError) (1025, "Error on rename of './cinder/#sql-2423_62' to './cinder/snapshots' (errno: 150)") '\nALTER TABLE snapshots DROP COLUMN cgsnapshot_id' ()
2014-09-11 18:05:55.095 TRACE cinder

The reason that drop column failed was because of the foreign key constraint. MySQL cannot drop column until the foreign key constraint is removed. So the solution is to remove the foreign key first, and then drop the column.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/122971

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/122971
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=71e78407954d108879bd51664f97fb5aeb5729dc
Submitter: Jenkins
Branch: master

commit 71e78407954d108879bd51664f97fb5aeb5729dc
Author: Xing Yang <email address hidden>
Date: Sat Sep 20 18:23:11 2014 -0400

    DB migration 25->24 failed when dropping column

    "cinder-manage db sync 24" failed when dropping column cgsnapshot_id
    from the snapshots table.

    The reason that drop column failed was because of the foreign key
    constraint. MySQL cannot drop column until the foreign key constraint
    is removed. So the solution is to remove the foreign key first, and
    then drop the column. This affects the cgsnapshot_id column in the
    snapshots table and the consistencygroup_id column in the volumes table.

    Change-Id: I89d5016be450ec91c7a7b1c42803add3f62c88df
    Closes-Bug: #1368213