vmware-nsx/quantum/db/api.py
Mark McLoughlin b5990a7bd7 Use oslo-config-2013.1b3
The cfg API is now available via the oslo-config library, so switch to
it and remove the copied-and-pasted version.

Add the 2013.1b3 tarball to tools/pip-requires - this will be changed
to 'oslo-config>=2013.1' when oslo-config is published to pypi. This
will happen in time for grizzly final.

Remove the 'deps = pep8' from tox.ini as it means all the other deps
get installed with easy_install which can't install oslo-config from
the URL.

Retain dummy cfg.py file until keystoneclient middleware has been
updated (I18c450174277c8e2d15ed93879da6cd92074c27a).

Change-Id: I4815aeb8a9341a31a250e920157f15ee15cfc5bc
2013-02-17 17:33:05 +00:00

228 lines
7.7 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 Nicira Networks, Inc.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
# @author: Somik Behera, Nicira Networks, Inc.
# @author: Brad Hall, Nicira Networks, Inc.
# @author: Dan Wendlandt, Nicira Networks, Inc.
import time
from eventlet import db_pool
from eventlet import greenthread
try:
import MySQLdb
except ImportError:
MySQLdb = None
from oslo.config import cfg
import sqlalchemy as sql
from sqlalchemy import create_engine
from sqlalchemy.exc import DisconnectionError
from sqlalchemy.interfaces import PoolListener
from sqlalchemy.orm import sessionmaker
from quantum.db import model_base
from quantum.openstack.common import log as logging
LOG = logging.getLogger(__name__)
SQL_CONNECTION_DEFAULT = 'sqlite://'
database_opts = [
cfg.StrOpt('sql_connection',
help=_('The SQLAlchemy connection string used to connect to '
'the database')),
cfg.IntOpt('sql_max_retries', default=-1,
help=_('Database reconnection retry times')),
cfg.IntOpt('reconnect_interval', default=2,
help=_('Database reconnection interval in seconds')),
cfg.IntOpt('sql_min_pool_size',
default=1,
help=_("Minimum number of SQL connections to keep open in a "
"pool")),
cfg.IntOpt('sql_max_pool_size',
default=5,
help=_("Maximum number of SQL connections to keep open in a "
"pool")),
cfg.IntOpt('sql_idle_timeout',
default=3600,
help=_("Timeout in seconds before idle sql connections are "
"reaped")),
cfg.BoolOpt('sql_dbpool_enable',
default=False,
help=_("Enable the use of eventlet's db_pool for MySQL")),
]
cfg.CONF.register_opts(database_opts, "DATABASE")
_ENGINE = None
_MAKER = None
BASE = model_base.BASEV2
class MySQLPingListener(object):
"""
Ensures that MySQL connections checked out of the
pool are alive.
Borrowed from:
http://groups.google.com/group/sqlalchemy/msg/a4ce563d802c929f
"""
def checkout(self, dbapi_con, con_record, con_proxy):
try:
dbapi_con.cursor().execute('select 1')
except dbapi_con.OperationalError, ex:
if ex.args[0] in (2006, 2013, 2014, 2045, 2055):
LOG.warn(_('Got mysql server has gone away: %s'), ex)
raise DisconnectionError(_("Database server went away"))
else:
raise
class SqliteForeignKeysListener(PoolListener):
"""
Ensures that the foreign key constraints are enforced in SQLite.
The foreign key constraints are disabled by default in SQLite,
so the foreign key constraints will be enabled here for every
database connection
"""
def connect(self, dbapi_con, con_record):
dbapi_con.execute('pragma foreign_keys=ON')
def configure_db():
"""
Establish the database, create an engine if needed, and
register the models.
"""
global _ENGINE
if not _ENGINE:
sql_connection = cfg.CONF.DATABASE.sql_connection
if not sql_connection:
LOG.warn(_("Option 'sql_connection' not specified "
"in any config file - using default "
"value '%s'" % SQL_CONNECTION_DEFAULT))
sql_connection = SQL_CONNECTION_DEFAULT
connection_dict = sql.engine.url.make_url(sql_connection)
engine_args = {
'pool_recycle': 3600,
'echo': False,
'convert_unicode': True,
}
if 'mysql' in connection_dict.drivername:
engine_args['listeners'] = [MySQLPingListener()]
if (MySQLdb is not None and
cfg.CONF.DATABASE.sql_dbpool_enable):
pool_args = {
'db': connection_dict.database,
'passwd': connection_dict.password or '',
'host': connection_dict.host,
'user': connection_dict.username,
'min_size': cfg.CONF.DATABASE.sql_min_pool_size,
'max_size': cfg.CONF.DATABASE.sql_max_pool_size,
'max_idle': cfg.CONF.DATABASE.sql_idle_timeout
}
creator = db_pool.ConnectionPool(MySQLdb, **pool_args)
engine_args['creator'] = creator.create
if (MySQLdb is None and cfg.CONF.DATABASE.sql_dbpool_enable):
LOG.warn(_("Eventlet connection pooling will not work without "
"python-mysqldb!"))
if 'sqlite' in connection_dict.drivername:
engine_args['listeners'] = [SqliteForeignKeysListener()]
if sql_connection == "sqlite://":
engine_args["connect_args"] = {'check_same_thread': False}
_ENGINE = create_engine(sql_connection, **engine_args)
sql.event.listen(_ENGINE, 'checkin', greenthread_yield)
if not register_models():
if cfg.CONF.DATABASE.reconnect_interval:
remaining = cfg.CONF.DATABASE.sql_max_retries
reconnect_interval = cfg.CONF.DATABASE.reconnect_interval
retry_registration(remaining, reconnect_interval)
def clear_db(base=BASE):
global _ENGINE, _MAKER
assert _ENGINE
unregister_models(base)
if _MAKER:
_MAKER.close_all()
_MAKER = None
_ENGINE.dispose()
_ENGINE = None
def get_session(autocommit=True, expire_on_commit=False):
"""Helper method to grab session"""
global _MAKER, _ENGINE
if not _MAKER:
assert _ENGINE
_MAKER = sessionmaker(bind=_ENGINE,
autocommit=autocommit,
expire_on_commit=expire_on_commit)
return _MAKER()
def retry_registration(remaining, reconnect_interval, base=BASE):
if remaining == -1:
remaining = 'infinite'
while True:
if remaining != 'infinite':
if remaining == 0:
LOG.error(_("Database connection lost, exit..."))
break
remaining -= 1
LOG.info(_("Unable to connect to database, %(remaining)s attempts "
"left. Retrying in %(reconnect_interval)s seconds"),
locals())
time.sleep(reconnect_interval)
if register_models(base):
break
def register_models(base=BASE):
"""Register Models and create properties"""
global _ENGINE
assert _ENGINE
try:
base.metadata.create_all(_ENGINE)
except sql.exc.OperationalError as e:
LOG.info(_("Database registration exception: %s"), e)
return False
return True
def unregister_models(base=BASE):
"""Unregister Models, useful clearing out data before testing"""
global _ENGINE
assert _ENGINE
base.metadata.drop_all(_ENGINE)
def greenthread_yield(dbapi_con, con_record):
"""
Ensure other greenthreads get a chance to execute by forcing a context
switch. With common database backends (eg MySQLdb and sqlite), there is
no implicit yield caused by network I/O since they are implemented by
C libraries that eventlet cannot monkey patch.
"""
greenthread.sleep(0)