heat-manage script fails when encrypting large database

[Pratik Mallya]

The heat-manage script loads all table entries at once during the process of encrypting parameters. This causes the process to run out of memory on production databases used for heat. We need to fix this so that it does the encryption in batches.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/197988
Committed: https://git.openstack.org/cgit/openstack/heat/commit/?id=7c90690accd68c9d9da440eea007345dc3c912c1
Submitter: Jenkins
Branch: master

commit 7c90690accd68c9d9da440eea007345dc3c912c1
Author: kairat_kushaev <email address hidden>
Date: Thu Jul 2 16:23:08 2015 +0300

    Add batching for heat-manage encrypt/decrypt

    When heat-manage executed encrypt/descrypt previously it
    requested all templates in db. It lead to some issues with memory.
    So the patch add batching for encrypt/descrypt operations:
    it allows to request only predefined number of templates,
    encrypt/decrypt them and request next batch of templates.
    It allows to reduce memory overhead when doing encrypt/decrypt
    operations.

    Co-Authored-By: Pratik Mallya <email address hidden>
    Change-Id: I6312235ca7de93a95672755c906156034647b177
    Closes-bug: #1470652