diff options
| -rw-r--r-- | nova/db/api.py | 11 | ||||
| -rw-r--r-- | nova/db/sqlalchemy/api.py | 5 | ||||
| -rw-r--r-- | nova/openstack/common/db/api.py | 100 | ||||
| -rw-r--r-- | nova/openstack/common/db/sqlalchemy/session.py | 35 | ||||
| -rw-r--r-- | openstack-common.conf | 2 |
5 files changed, 111 insertions, 42 deletions
diff --git a/nova/db/api.py b/nova/db/api.py index e38cf1866..d14999b45 100644 --- a/nova/db/api.py +++ b/nova/db/api.py @@ -47,14 +47,11 @@ from oslo.config import cfg from nova.cells import rpcapi as cells_rpcapi from nova import exception +from nova.openstack.common.db import api as db_api from nova.openstack.common import log as logging -from nova import utils db_opts = [ - cfg.StrOpt('db_backend', - default='sqlalchemy', - help='The backend to use for db'), cfg.BoolOpt('enable_new_services', default=True, help='Services to be added to the available pool on create'), @@ -69,8 +66,10 @@ db_opts = [ CONF = cfg.CONF CONF.register_opts(db_opts) -IMPL = utils.LazyPluggable('db_backend', - sqlalchemy='nova.db.sqlalchemy.api') +_BACKEND_MAPPING = {'sqlalchemy': 'nova.db.sqlalchemy.api'} + + +IMPL = db_api.DBAPI(backend_mapping=_BACKEND_MAPPING) LOG = logging.getLogger(__name__) diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py index d13c60969..360bd1b3a 100644 --- a/nova/db/sqlalchemy/api.py +++ b/nova/db/sqlalchemy/api.py @@ -78,6 +78,11 @@ get_engine = db_session.get_engine get_session = db_session.get_session +def get_backend(): + """The backend is this module itself.""" + return sys.modules[__name__] + + def require_admin_context(f): """Decorator to require admin request context. diff --git a/nova/openstack/common/db/api.py b/nova/openstack/common/db/api.py new file mode 100644 index 000000000..edb42074f --- /dev/null +++ b/nova/openstack/common/db/api.py @@ -0,0 +1,100 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright (c) 2013 Rackspace Hosting +# 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. + +"""Multiple DB API backend support. + +Supported configuration options: + +`db_backend`: DB backend name or full module path to DB backend module. +`dbapi_use_tpool`: Enable thread pooling of DB API calls. + +A DB backend module should implement a method named 'get_backend' which +takes no arguments. The method can return any object that implements DB +API methods. + +*NOTE*: There are bugs in eventlet when using tpool combined with +threading locks. The python logging module happens to use such locks. To +work around this issue, be sure to specify thread=False with +eventlet.monkey_patch(). + +A bug for eventlet has been filed here: + +https://bitbucket.org/eventlet/eventlet/issue/137/ +""" +import functools + +from nova.openstack.common import cfg +from nova.openstack.common import lockutils +from nova.openstack.common import importutils + + +db_opts = [ + cfg.StrOpt('db_backend', + default='sqlalchemy', + help='The backend to use for db'), + cfg.BoolOpt('dbapi_use_tpool', + default=False, + help='Enable the experimental use of thread pooling for ' + 'all DB API calls') +] + +CONF = cfg.CONF +CONF.register_opts(db_opts) + + +class DBAPI(object): + def __init__(self, backend_mapping=None): + if backend_mapping is None: + backend_mapping = {} + self.__backend = None + self.__backend_mapping = backend_mapping + + @lockutils.synchronized('dbapi_backend', 'nova-') + def __get_backend(self): + """Get the actual backend. May be a module or an instance of + a class. Doesn't matter to us. We do this synchronized as it's + possible multiple greenthreads started very quickly trying to do + DB calls and eventlet can switch threads before self.__backend gets + assigned. + """ + if self.__backend: + # Another thread assigned it + return self.__backend + backend_name = CONF.db_backend + self.__use_tpool = CONF.dbapi_use_tpool + if self.__use_tpool: + from eventlet import tpool + self.__tpool = tpool + # Import the untranslated name if we don't have a + # mapping. + backend_path = self.__backend_mapping.get(backend_name, + backend_name) + backend_mod = importutils.import_module(backend_path) + self.__backend = backend_mod.get_backend() + return self.__backend + + def __getattr__(self, key): + backend = self.__backend or self.__get_backend() + attr = getattr(backend, key) + if not self.__use_tpool or not hasattr(attr, '__call__'): + return attr + + def tpool_wrapper(*args, **kwargs): + return self.__tpool.execute(attr, *args, **kwargs) + + functools.update_wrapper(tpool_wrapper, attr) + return tpool_wrapper diff --git a/nova/openstack/common/db/sqlalchemy/session.py b/nova/openstack/common/db/sqlalchemy/session.py index 93bfa9b15..fb86d9ca5 100644 --- a/nova/openstack/common/db/sqlalchemy/session.py +++ b/nova/openstack/common/db/sqlalchemy/session.py @@ -244,7 +244,6 @@ import os.path import re import time -from eventlet import db_pool from eventlet import greenthread from oslo.config import cfg from sqlalchemy.exc import DisconnectionError, OperationalError, IntegrityError @@ -253,14 +252,10 @@ import sqlalchemy.orm from sqlalchemy.pool import NullPool, StaticPool from sqlalchemy.sql.expression import literal_column -from nova.openstack.common import importutils from nova.openstack.common import log as logging from nova.openstack.common.gettextutils import _ from nova.openstack.common import timeutils -MySQLdb = importutils.try_import('MySQLdb') -if MySQLdb is not None: - from MySQLdb.constants import CLIENT as mysql_client_constants sql_opts = [ cfg.StrOpt('sql_connection', @@ -303,9 +298,6 @@ sql_opts = [ cfg.BoolOpt('sql_connection_trace', default=False, help='Add python stack traces to SQL as comment strings'), - cfg.BoolOpt('sql_dbpool_enable', - default=False, - help="enable the use of eventlet's db_pool for MySQL"), ] CONF = cfg.CONF @@ -517,33 +509,6 @@ def create_engine(sql_connection): if CONF.sql_connection == "sqlite://": engine_args["poolclass"] = StaticPool engine_args["connect_args"] = {'check_same_thread': False} - elif all((CONF.sql_dbpool_enable, MySQLdb, - "mysql" in connection_dict.drivername)): - LOG.info(_("Using mysql/eventlet db_pool.")) - # MySQLdb won't accept 'None' in the password field - password = connection_dict.password or '' - pool_args = { - 'db': connection_dict.database, - 'passwd': password, - 'host': connection_dict.host, - 'user': connection_dict.username, - 'min_size': CONF.sql_min_pool_size, - 'max_size': CONF.sql_max_pool_size, - 'max_idle': CONF.sql_idle_timeout, - 'client_flag': mysql_client_constants.FOUND_ROWS} - - pool = db_pool.ConnectionPool(MySQLdb, **pool_args) - - def creator(): - conn = pool.create() - if isinstance(conn, tuple): - # NOTE(belliott) eventlet >= 0.10 returns a tuple - now, now, conn = conn - - return conn - - engine_args['creator'] = creator - else: engine_args['pool_size'] = CONF.sql_max_pool_size if CONF.sql_max_overflow is not None: diff --git a/openstack-common.conf b/openstack-common.conf index abbc7570e..463abd1c2 100644 --- a/openstack-common.conf +++ b/openstack-common.conf @@ -1,7 +1,7 @@ [DEFAULT] # The list of modules to copy from openstack-common -modules=cliutils,context,db,db.sqlalchemy,excutils,eventlet_backdoor,fileutils,gettextutils,importutils,jsonutils,local,lockutils,log,network_utils,notifier,plugin,policy,rootwrap,setup,timeutils,rpc,uuidutils,install_venv_common,flakes,version +modules=cliutils,context,db,db.api,db.sqlalchemy,excutils,eventlet_backdoor,fileutils,gettextutils,importutils,jsonutils,local,lockutils,log,network_utils,notifier,plugin,policy,rootwrap,setup,timeutils,rpc,uuidutils,install_venv_common,flakes,version # The base module to hold the copy of openstack.common base=nova |