Comment 6 for bug 1378215

Reviewed: https://review.openstack.org/130029
Committed: https://git.openstack.org/cgit/openstack/glance/commit/?id=4b5cb74e5120decd618399d642ebf06ad45d26a6
Submitter: Jenkins
Branch: stable/icehouse

commit 4b5cb74e5120decd618399d642ebf06ad45d26a6
Author: ankitagrawal <email address hidden>
Date: Tue Oct 7 07:36:10 2014 -0700

    Can not delete images if db deadlock occurs

    Glance api returns 500 Internal Server Error, if db deadlock occurs
    in glance-registry for some reason while deleting an image.

    Added `_retry_on_deadlock` decorator from Nova since we don't depend
    on retrying library in Icehouse. Used this decorator on image_destroy
    when db deadlock occures during image delete, which will again try to
    delete the image from database.

    Conflicts:
            glance/tests/unit/test_db.py

    Note: In this patch, I've made few additional changes to add retrying
    logic because retrying library is not available in Icehouse.

    Closes-bug: 1378215
    Change-Id: Ifad403e363daf368e846b5b6838432a7bedbe81a
    (cherry picked from commit dae0fa8f1071be41d5541e9a5254abea48f5ba36)