Comment 18 for bug 1813147

Looks like this is our biggest issue in the functional py35 job now:

2019-02-06 21:04:13.978116 | ubuntu-xenial | b'/home/zuul/src/git.openstack.org/openstack/nova/.tox/functional-py35/lib/python3.5/site-packages/oslo_service/threadgroup.py:193: DeprecationWarning: Calling add_timer() with arguments to the callback function is deprecated. Use add_timer_args() instead.'