diff options
| -rw-r--r-- | nova/db/sqlalchemy/session.py | 144 |
1 files changed, 78 insertions, 66 deletions
diff --git a/nova/db/sqlalchemy/session.py b/nova/db/sqlalchemy/session.py index 6c349e0c2..ccd98a377 100644 --- a/nova/db/sqlalchemy/session.py +++ b/nova/db/sqlalchemy/session.py @@ -48,11 +48,25 @@ def get_session(autocommit=True, expire_on_commit=False): _MAKER = get_maker(engine, autocommit, expire_on_commit) session = _MAKER() + session = wrap_session(session) + return session + + +def wrap_session(session): + """Return a session whose exceptions are wrapped.""" session.query = nova.exception.wrap_db_error(session.query) session.flush = nova.exception.wrap_db_error(session.flush) return session +def get_engine(): + """Return a SQLAlchemy engine.""" + global _ENGINE + if _ENGINE is None: + _ENGINE = create_engine(FLAGS.sql_connection) + return _ENGINE + + def synchronous_switch_listener(dbapi_conn, connection_rec): """Switch sqlite connections to non-synchronous mode""" dbapi_conn.execute("PRAGMA synchronous = OFF") @@ -106,72 +120,70 @@ def is_db_connection_error(args): return False -def get_engine(): - """Return a SQLAlchemy engine.""" - global _ENGINE - if _ENGINE is None: - connection_dict = sqlalchemy.engine.url.make_url(FLAGS.sql_connection) - - engine_args = { - "pool_recycle": FLAGS.sql_idle_timeout, - "echo": False, - 'convert_unicode': True, - } - - # Map our SQL debug level to SQLAlchemy's options - if FLAGS.sql_connection_debug >= 100: - engine_args['echo'] = 'debug' - elif FLAGS.sql_connection_debug >= 50: - engine_args['echo'] = True - - if "sqlite" in connection_dict.drivername: - engine_args["poolclass"] = NullPool - - if FLAGS.sql_connection == "sqlite://": - engine_args["poolclass"] = StaticPool - engine_args["connect_args"] = {'check_same_thread': False} - - _ENGINE = sqlalchemy.create_engine(FLAGS.sql_connection, **engine_args) - - sqlalchemy.event.listen(_ENGINE, 'checkin', greenthread_yield) - - if 'mysql' in connection_dict.drivername: - sqlalchemy.event.listen(_ENGINE, 'checkout', ping_listener) - elif 'sqlite' in connection_dict.drivername: - if not FLAGS.sqlite_synchronous: - sqlalchemy.event.listen(_ENGINE, 'connect', - synchronous_switch_listener) - sqlalchemy.event.listen(_ENGINE, 'connect', add_regexp_listener) - - if (FLAGS.sql_connection_trace and - _ENGINE.dialect.dbapi.__name__ == 'MySQLdb'): - import MySQLdb.cursors - _do_query = debug_mysql_do_query() - setattr(MySQLdb.cursors.BaseCursor, '_do_query', _do_query) - - try: - _ENGINE.connect() - except OperationalError, e: - if not is_db_connection_error(e.args[0]): - raise - - remaining = FLAGS.sql_max_retries - if remaining == -1: - remaining = 'infinite' - while True: - msg = _('SQL connection failed. %s attempts left.') - LOG.warn(msg % remaining) - if remaining != 'infinite': - remaining -= 1 - time.sleep(FLAGS.sql_retry_interval) - try: - _ENGINE.connect() - break - except OperationalError, e: - if (remaining != 'infinite' and remaining == 0) or \ - not is_db_connection_error(e.args[0]): - raise - return _ENGINE +def create_engine(sql_connection): + """Return a new SQLAlchemy engine.""" + connection_dict = sqlalchemy.engine.url.make_url(sql_connection) + + engine_args = { + "pool_recycle": FLAGS.sql_idle_timeout, + "echo": False, + 'convert_unicode': True, + } + + # Map our SQL debug level to SQLAlchemy's options + if FLAGS.sql_connection_debug >= 100: + engine_args['echo'] = 'debug' + elif FLAGS.sql_connection_debug >= 50: + engine_args['echo'] = True + + if "sqlite" in connection_dict.drivername: + engine_args["poolclass"] = NullPool + + if FLAGS.sql_connection == "sqlite://": + engine_args["poolclass"] = StaticPool + engine_args["connect_args"] = {'check_same_thread': False} + + engine = sqlalchemy.create_engine(sql_connection, **engine_args) + + sqlalchemy.event.listen(engine, 'checkin', greenthread_yield) + + if 'mysql' in connection_dict.drivername: + sqlalchemy.event.listen(engine, 'checkout', ping_listener) + elif 'sqlite' in connection_dict.drivername: + if not FLAGS.sqlite_synchronous: + sqlalchemy.event.listen(engine, 'connect', + synchronous_switch_listener) + sqlalchemy.event.listen(engine, 'connect', add_regexp_listener) + + if (FLAGS.sql_connection_trace and + engine.dialect.dbapi.__name__ == 'MySQLdb'): + import MySQLdb.cursors + _do_query = debug_mysql_do_query() + setattr(MySQLdb.cursors.BaseCursor, '_do_query', _do_query) + + try: + engine.connect() + except OperationalError, e: + if not is_db_connection_error(e.args[0]): + raise + + remaining = FLAGS.sql_max_retries + if remaining == -1: + remaining = 'infinite' + while True: + msg = _('SQL connection failed. %s attempts left.') + LOG.warn(msg % remaining) + if remaining != 'infinite': + remaining -= 1 + time.sleep(FLAGS.sql_retry_interval) + try: + engine.connect() + break + except OperationalError, e: + if (remaining != 'infinite' and remaining == 0) or \ + not is_db_connection_error(e.args[0]): + raise + return engine def get_maker(engine, autocommit=True, expire_on_commit=False): |