> On 08 Dec 2015, at 21:10, Mike Bayer <mba...@redhat.com> wrote: > > > > On 12/08/2015 07:28 AM, Renat Akhmerov wrote: >> Hi, >> >> Moshe, thanks a lot for bringing this up. I remember I tried to find a >> way to change isolation level per connection but also was unable to do that. > > Current SQLAlchemy has a lot of isolation level options. There is a > complete guide to doing this from an ORM perspective at > http://docs.sqlalchemy.org/en/rel_1_0/orm/session_transaction.html#setting-transaction-isolation-levels. > > > On a per-connection basis, you would use the isolation_level execution > option. An example of how to integrate this into Session usage is in > this section at > http://docs.sqlalchemy.org/en/rel_1_0/orm/session_transaction.html#setting-isolation-for-individual-sessions. > > In oslo.db, there's no engine-wide isolation level setting available, > however when the engine is returned from the oslo.db version of > create_engine, you can immediately get a copy of that engine with the > isolation_level option set by calling: > > engine = oslo_db.create_engine(...) > engine = engine.execution_options(isolation_level='READ_COMMITTED’)
This is very helpful, thanks Mike. We’ll try to use this way. > The future of oslo.db is oriented around the upgraded "enginefacade" > API. Adding isolation hooks to this new API is a TODO, but is > straightforward; if you're using the new enginefacade API, I can > expedite having the appropriate hooks added in. Yes, I think this is a too important property to just ignore it. Renat Akhmerov @ Mirantis Inc. __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
