Listen for foreign key changes and expire related relationships.
With this, we can remove OVO code that refreshes / detaches models on
each fetch. The patch also removes a bunch of expunge calls in plugin
code.
writer.using context manager is added to _get_subnets so that segment
plugin's _notify_subnet_updated handler that calls to _get_subnets
doesn't use the facade-less context.session that in specific cases may
cache old models from previous sessions when used in mixed
facade/facade-less environment.
This patch bumps SQLAlchemy minimal requirement to >= 1.2.0 because
pending_to_persistent event didn't exist before this version. It could be >=
1.1.0 if not for the fact that all 1.1.x releases have a bug that results in
breakage of test_update_with_none_and_own_mac_for_duplicate_ip due to obscure
import ordering issue in the library.
(The issue is fixed by https://github.com/zzzeek/sqlalchemy/commit/
63ff0140705207198545e3a0d7868a5ba8486e93)
Partially-Implements: blueprint enginefacade-switch
Partially-Implements: blueprint adopt-oslo-versioned-objects-for-db
Co-Authored-By: Michael Bayer <mike_mp@zzzcomputing.com>
Change-Id: I18c6794f99d2847c208dfd6e9eb187d53b657a05
90ede813b0