Rolling upgrades: backward incompatible changes in versioned objects

[Grzegorz Grasza]

In the past, changes to versioned objects were done without implementing the obj_make_compatible method, which breaks rolling upgrades (upgrades when Ironic services are run at different versions simultaneously)
To prevent introduction of incompatible changes to versioned objects an object version hash test should be introduced, together with documentation.

This was recently discussed in Magnum:

http://lists.openstack.org/pipermail/openstack-dev/2015-August/072975.html

As a result, two patches were merged:

https://review.openstack.org/#/c/217342/ - implementation

https://review.openstack.org/#/c/220539/ - documentation

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/249624

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/249624
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=74bd3b18659daf7571f8addbd870b48e614e1f73
Submitter: Jenkins
Branch: master

commit 74bd3b18659daf7571f8addbd870b48e614e1f73
Author: Lin Tan <email address hidden>
Date: Wed Nov 25 15:49:05 2015 +0800

    Add a test to enforce object version bump correctly

    Add a test to help developers to check if the change of objects
    need a version bump.

    Any changes of object fields or remotable methods need to bump
    its version. Use oslo_versionobjects to generate the hashes and
    compare with a pre-define hash map.

    Change-Id: I5c12ab72937f05ba46eb58d049f9b7fc7c806218
    Closes-Bug: 1502895
    Implements: blueprint online-upgrade-support

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/ironic 4.3.0 release.