neutron/neutron/db/api.py

136 lines
4.5 KiB
Python

# Copyright 2011 VMware, 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.
import contextlib
from debtcollector import moves
from oslo_config import cfg
from oslo_db import api as oslo_db_api
from oslo_db import exception as db_exc
from oslo_db.sqlalchemy import enginefacade
from oslo_utils import excutils
import osprofiler.sqlalchemy
import six
import sqlalchemy
from sqlalchemy.orm import exc
from neutron.common import exceptions
from neutron.common import profiler # noqa
context_manager = enginefacade.transaction_context()
context_manager.configure(sqlite_fk=True)
_PROFILER_INITIALIZED = False
MAX_RETRIES = 10
def is_retriable(e):
if _is_nested_instance(e, (db_exc.DBDeadlock, exc.StaleDataError,
db_exc.DBConnectionError,
db_exc.DBDuplicateEntry, db_exc.RetryRequest)):
return True
# looking savepoints mangled by deadlocks. see bug/1590298 for details.
return _is_nested_instance(e, db_exc.DBError) and '1305' in str(e)
is_deadlock = moves.moved_function(is_retriable, 'is_deadlock', __name__,
message='use "is_retriable" instead',
version='newton', removal_version='ocata')
retry_db_errors = oslo_db_api.wrap_db_retry(
max_retries=MAX_RETRIES,
retry_interval=0.1,
inc_retry_interval=True,
exception_checker=is_retriable
)
def reraise_as_retryrequest(f):
"""Packs retriable exceptions into a RetryRequest."""
@six.wraps(f)
def wrapped(*args, **kwargs):
try:
return f(*args, **kwargs)
except Exception as e:
with excutils.save_and_reraise_exception() as ctx:
if is_retriable(e):
ctx.reraise = False
raise db_exc.RetryRequest(e)
return wrapped
def _is_nested_instance(e, etypes):
"""Check if exception or its inner excepts are an instance of etypes."""
return (isinstance(e, etypes) or
isinstance(e, exceptions.MultipleExceptions) and
any(_is_nested_instance(i, etypes) for i in e.inner_exceptions))
# TODO(akamyshnikova) this code should be in oslo.db
def _set_profiler():
global _PROFILER_INITIALIZED
if (not _PROFILER_INITIALIZED and cfg.CONF.profiler.enabled and
cfg.CONF.profiler.trace_sqlalchemy):
_PROFILER_INITIALIZED = True
osprofiler.sqlalchemy.add_tracing(
sqlalchemy, context_manager.get_legacy_facade().get_engine(), "db")
@contextlib.contextmanager
def exc_to_retry(exceptions):
try:
yield
except Exception as e:
with excutils.save_and_reraise_exception() as ctx:
if _is_nested_instance(e, exceptions):
ctx.reraise = False
raise db_exc.RetryRequest(e)
#TODO(akamyshnikova): when all places in the code, which use sessions/
# connections will be updated, this won't be needed
def get_engine():
"""Helper method to grab engine."""
_set_profiler()
return context_manager.get_legacy_facade().get_engine()
def dispose():
# TODO(akamyshnikova): Use context_manager.dispose_pool() when it is
# available in oslo.db
if context_manager._factory._started:
get_engine().pool.dispose()
#TODO(akamyshnikova): when all places in the code, which use sessions/
# connections will be updated, this won't be needed
def get_session(autocommit=True, expire_on_commit=False, use_slave=False):
"""Helper method to grab session."""
_set_profiler()
return context_manager.get_legacy_facade().get_session(
autocommit=autocommit, expire_on_commit=expire_on_commit,
use_slave=use_slave)
@contextlib.contextmanager
def autonested_transaction(sess):
"""This is a convenience method to not bother with 'nested' parameter."""
if sess.is_active:
session_context = sess.begin(nested=True)
else:
session_context = sess.begin(subtransactions=True)
with session_context as tx:
yield tx