From 1d9fd2aec00cb85034e5a23cc1beac33c74e0110 Mon Sep 17 00:00:00 2001 From: Eugene Nikanorov Date: Mon, 11 May 2015 01:34:35 +0400 Subject: [PATCH] Randomize tunnel id query to avoid contention When networks are created rapidly, neutron-servers compete for segmentation ids which creates too much contention and may lead to inability to choose available id in hardcoded amount of attempts (11) Randomize tunnel id selection so that condition is not hit. Change-Id: I7068f90fe4927e6e693f8a62cb704213b2da2920 Related-Bug: #1382064 Closes-Bug: #1454434 --- neutron/plugins/ml2/drivers/helpers.py | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/neutron/plugins/ml2/drivers/helpers.py b/neutron/plugins/ml2/drivers/helpers.py index 2404947d520..1e8b1fca01b 100644 --- a/neutron/plugins/ml2/drivers/helpers.py +++ b/neutron/plugins/ml2/drivers/helpers.py @@ -13,6 +13,8 @@ # License for the specific language governing permissions and limitations # under the License. +import random + from oslo_config import cfg from oslo_db import exception as db_exc from oslo_log import log @@ -24,6 +26,8 @@ from neutron.plugins.ml2 import driver_api as api LOG = log.getLogger(__name__) +IDPOOL_SELECT_SIZE = 100 + class BaseTypeDriver(api.TypeDriver): """BaseTypeDriver for functions common to Segment and flat.""" @@ -121,12 +125,13 @@ class SegmentTypeDriver(BaseTypeDriver): filter_by(allocated=False, **filters)) # Selected segment can be allocated before update by someone else, - alloc = select.first() + allocs = select.limit(IDPOOL_SELECT_SIZE).all() - if not alloc: + if not allocs: # No resource available return + alloc = random.choice(allocs) raw_segment = dict((k, alloc[k]) for k in self.primary_keys) LOG.debug("%(type)s segment allocate from pool " "started with %(segment)s ",