b15a6e8c7d
subtransactions are being removed from SQLAlchemy, as well as autocommit sessions [0] [1] [0] https://docs.sqlalchemy.org/en/14/changelog/migration_20.html#\ session-subtransaction-behavior-removed [1] https://docs.sqlalchemy.org/en/14/changelog/migration_20.html#\ library-level-but-not-driver-level-autocommit-removed-from-both-core-and-orm Change-Id: Ie32a17c9bf91b05752bc0457151b6b0aa4151264
77 lines
2.2 KiB
Python
77 lines
2.2 KiB
Python
# Copyright 2014 Rackspace
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import time
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from sqlalchemy.sql.expression import select
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from oslo_config import cfg
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from oslo_db.sqlalchemy import enginefacade
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from oslo_log import log as logging
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LOG = logging.getLogger(__name__)
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_FACADE = None
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def _create_facade_lazily():
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global _FACADE
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if _FACADE is None:
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_FACADE = True
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enginefacade.configure(sqlite_fk=True, expire_on_commit=True)
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def _get_transaction_context(reader=False):
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_create_facade_lazily()
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# TODO(gthiemonge) Create and use new functions to get read-only sessions
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if reader:
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context = enginefacade.reader
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else:
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context = enginefacade.writer
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return context
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def _get_sessionmaker(reader=False):
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context = _get_transaction_context(reader)
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return context.get_sessionmaker()
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def get_engine():
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context = _get_transaction_context()
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return context.get_engine()
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def get_session():
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"""Helper method to grab session."""
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return _get_sessionmaker()()
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def session():
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return _get_sessionmaker()
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def wait_for_connection(exit_event):
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"""Helper method to wait for DB connection"""
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down = True
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while down and not exit_event.is_set():
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try:
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LOG.debug('Trying to re-establish connection to database.')
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get_engine().scalar(select([1]))
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down = False
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LOG.debug('Connection to database re-established.')
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except Exception:
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retry_interval = cfg.CONF.database.retry_interval
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LOG.exception('Connection to database failed. Retrying in %s '
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'seconds.', retry_interval)
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time.sleep(retry_interval)
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