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Diffstat (limited to 'ceilometer/storage/sqlalchemy/session.py')
| -rw-r--r-- | ceilometer/storage/sqlalchemy/session.py | 193 |
1 files changed, 0 insertions, 193 deletions
diff --git a/ceilometer/storage/sqlalchemy/session.py b/ceilometer/storage/sqlalchemy/session.py deleted file mode 100644 index ce95e12e..00000000 --- a/ceilometer/storage/sqlalchemy/session.py +++ /dev/null @@ -1,193 +0,0 @@ -# vim: tabstop=4 shiftwidth=4 softtabstop=4 - -# Copyright 2010 United States Government as represented by the -# Administrator of the National Aeronautics and Space Administration. -# 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. - -"""Session Handling for SQLAlchemy backend.""" - -import re -import time - -from oslo.config import cfg -import sqlalchemy -import sqlalchemy.exc as exc -import sqlalchemy.orm -import sqlalchemy.pool as pool - -from ceilometer.openstack.common import log - - -LOG = log.getLogger(__name__) - -_MAKER = None -_ENGINE = None - -sql_opts = [ - cfg.IntOpt('sql_connection_debug', - default=0, - help='Verbosity of SQL debugging information. 0=None, ' - '100=Everything'), - cfg.BoolOpt('sql_connection_trace', - default=False, - help='Add python stack traces to SQL as comment strings'), - cfg.BoolOpt('sqlite_synchronous', - default=True, - help='If passed, use synchronous mode for sqlite'), - cfg.IntOpt('sql_idle_timeout', - default=3600, - help='timeout before idle sql connections are reaped'), - cfg.IntOpt('sql_max_retries', - default=10, - help='maximum db connection retries during startup. ' - '(setting -1 implies an infinite retry count)'), - cfg.IntOpt('sql_retry_interval', - default=10, - help='interval between retries of opening a sql connection'), -] - -cfg.CONF.register_opts(sql_opts) - - -def get_session(database_connection, conf, - autocommit=True, expire_on_commit=False, autoflush=True): - """Return a SQLAlchemy session.""" - global _MAKER - - if _MAKER is None: - engine = get_engine(database_connection, conf) - _MAKER = get_maker(engine, autocommit, expire_on_commit, autoflush) - - session = _MAKER() - return session - - -def synchronous_switch_listener(dbapi_conn, connection_rec): - """Switch sqlite connections to non-synchronous mode.""" - dbapi_conn.execute("PRAGMA synchronous = OFF") - - -def add_regexp_listener(dbapi_con, con_record): - """Add REGEXP function to sqlite connections.""" - - def regexp(expr, item): - reg = re.compile(expr) - return reg.search(unicode(item)) is not None - dbapi_con.create_function('regexp', 2, regexp) - - -def ping_listener(dbapi_conn, connection_rec, connection_proxy): - """ - Ensures that MySQL connections checked out of the - pool are alive. - - Borrowed from: - http://groups.google.com/group/sqlalchemy/msg/a4ce563d802c929f - """ - try: - dbapi_conn.cursor().execute('select 1') - except dbapi_conn.OperationalError, ex: - if ex.args[0] in (2006, 2013, 2014, 2045, 2055): - LOG.warn('Got mysql server has gone away: %s', ex) - raise exc.DisconnectionError("Database server went away") - else: - raise - - -def is_db_connection_error(args): - """Return True if error in connecting to db.""" - # NOTE(adam_g): This is currently MySQL specific and needs to be extended - # to support Postgres and others. - conn_err_codes = ('2002', '2003', '2006') - for err_code in conn_err_codes: - if args.find(err_code) != -1: - return True - return False - - -def get_engine(database_connection, conf): - """Return a SQLAlchemy engine.""" - global _ENGINE - if _ENGINE is None: - connection_dict = sqlalchemy.engine.url.make_url( - database_connection) - - engine_args = { - "pool_recycle": conf.sql_idle_timeout, - "echo": False, - 'convert_unicode': True, - } - - # Map our SQL debug level to SQLAlchemy's options - if conf.sql_connection_debug >= 100: - engine_args['echo'] = 'debug' - elif conf.sql_connection_debug >= 50: - engine_args['echo'] = True - - if "sqlite" in connection_dict.drivername: - engine_args["poolclass"] = pool.NullPool - - if database_connection == "sqlite://": - engine_args["poolclass"] = pool.StaticPool - engine_args["connect_args"] = {'check_same_thread': False} - - _ENGINE = sqlalchemy.create_engine(database_connection, - **engine_args) - - if 'mysql' in connection_dict.drivername: - sqlalchemy.event.listen(_ENGINE, 'checkout', ping_listener) - elif "sqlite" in connection_dict.drivername: - if not conf.sqlite_synchronous: - sqlalchemy.event.listen(_ENGINE, 'connect', - synchronous_switch_listener) - sqlalchemy.event.listen(_ENGINE, 'connect', add_regexp_listener) - - if (conf.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 exc.OperationalError, e: - if not is_db_connection_error(e.args[0]): - raise - - remaining = conf.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(conf.sql_retry_interval) - try: - _ENGINE.connect() - break - except exc.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, autoflush=True): - """Return a SQLAlchemy sessionmaker using the given engine.""" - return sqlalchemy.orm.sessionmaker(bind=engine, - autocommit=autocommit, - autoflush=autoflush, - expire_on_commit=expire_on_commit) |