openstack/neutron
Code Issues Proposed changes

Remove nested transaction from ipam driver

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Using nested transaction in reference ipam driver causes rewriting
original exception due failure to restore to safepoint in case of
DeadLock.

DBDeadlock exception gets replaced with DBAPIError. It prevents db_retry
wrapper from working correctly.

This patch removed nested transaction block from reference ipam driver.

Change-Id: Ib710e87b0132aae3cd3afd12c5448961f1a3b25c
Partial-Bug: #1571666
This commit is contained in:
Pavel Bondar 2016-04-18 17:56:08 +03:00
parent acca136721
commit ad2d7d3a8f
1 changed files with 22 additions and 26 deletions
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12
neutron/ipam/drivers/neutrondb_ipam/driver.py
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@ -21,7 +21,6 @@ from oslo_utils import uuidutils
from neutron._i18n import _, _LE
from neutron.common import ipv6_utils
from neutron.db import api as db_api
from neutron.ipam import driver as ipam_base
from neutron.ipam.drivers.neutrondb_ipam import db_api as ipam_db_api
from neutron.ipam import exceptions as ipam_exc
@ -326,16 +325,13 @@ class NeutronDbSubnet(ipam_base.Subnet):
return ip_address, ip_range['allocation_pool_id']
def allocate(self, address_request):
# NOTE(salv-orlando): Creating a new db session might be a rather
# dangerous thing to do, if executed from within another database
# transaction. Therefore the IPAM driver should never be
# called from within a database transaction, which is also good
# practice since in the general case these drivers may interact
# with remote backends
# NOTE(pbondar): Ipam driver is always called in context of already
# running transaction, which is started on create_port or upper level.
# To be able to do rollback/retry actions correctly ipam driver
# should not create new nested transaction blocks.
session = self._context.session
all_pool_id = None
auto_generated = False
with db_api.autonested_transaction(session):
# NOTE(salv-orlando): It would probably better to have a simpler
# model for address requests and just check whether there is a
# specific IP address specified in address_request