Retry to set loadbalancer prov status on failures

In case of DB outages when a flow is running, an exception is caught and
the flow is reverted. In most of the flows, the revert function of the
first task's (the last to be reverted) unlocks the load balancer by
setting its provisioning status (to ERROR or ACTIVE, depending on the
flow), but it fails if the DB is not reachable, leaving the LB in
a PENDING_* state.
This commit adds tenacity.retry to those functions, Octavia retries to
set the status during ~2h45 (2000 attempts, 1 sec initial delay, 5 sec
max delay).

Closes-Bug: #2036952
Change-Id: I458dd6d6f5383edc24116ea0fa27e3a593044146
(cherry picked from commit be91493332)
This commit is contained in:
Gregory Thiemonge 2023-09-25 07:48:01 -04:00
parent 853d0f69e4
commit 96782e2c54
6 changed files with 209 additions and 49 deletions

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@ -73,6 +73,14 @@ configuration from successfully completing. In this case the load balancer is
continuing to process traffic through the load balancer, but might not have
applied the latest configuration updates yet.
A load balancer in a PENDING provisioning status is immutable, it cannot be
updated or deleted by another process, this PENDING status acts as a lock on
the resource.
If a database outage occurs while a load balancer is deleted, created or
updated, the Octavia control plane will try to remove the PENDING status and
set it to ERROR during a long period of time (around 2h45min with the default
settings), to prevent the resource from remaining immutable.
Monitoring load balancer functionality
--------------------------------------

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@ -534,7 +534,18 @@ controller_worker_opts = [
cfg.BoolOpt('event_notifications', default=True,
help=_('Enable octavia event notifications. See '
'oslo_messaging_notifications section for additional '
'requirements.'))
'requirements.')),
# 2000 attempts is around 2h45 with the default settings
cfg.IntOpt('db_commit_retry_attempts', default=2000,
help=_('The number of times the database action will be '
'attempted.')),
cfg.IntOpt('db_commit_retry_initial_delay', default=1,
help=_('The initial delay before a retry attempt.')),
cfg.IntOpt('db_commit_retry_backoff', default=1,
help=_('The time to backoff retry attempts.')),
cfg.IntOpt('db_commit_retry_max', default=5,
help=_('The maximum amount of time to wait between retry '
'attempts.')),
]
task_flow_opts = [

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@ -14,18 +14,32 @@
""" Methods common to the controller work tasks."""
from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import excutils
import tenacity
from octavia.common import constants
from octavia.db import api as db_apis
from octavia.db import repositories as repo
CONF = cfg.CONF
LOG = logging.getLogger(__name__)
class TaskUtils(object):
"""Class of helper/utility methods used by tasks."""
status_update_retry = tenacity.retry(
retry=tenacity.retry_if_exception_type(Exception),
wait=tenacity.wait_incrementing(
CONF.controller_worker.db_commit_retry_initial_delay,
CONF.controller_worker.db_commit_retry_backoff,
CONF.controller_worker.db_commit_retry_max),
stop=tenacity.stop_after_attempt(
CONF.controller_worker.db_commit_retry_attempts),
after=tenacity.after_log(LOG, logging.DEBUG))
def __init__(self, **kwargs):
self.amphora_repo = repo.AmphoraRepository()
self.health_mon_repo = repo.HealthMonitorRepository()
@ -160,6 +174,7 @@ class TaskUtils(object):
"provisioning status to ERROR due to: "
"%(except)s", {'list': listener_id, 'except': str(e)})
@status_update_retry
def mark_loadbalancer_prov_status_error(self, loadbalancer_id):
"""Sets a load balancer provisioning status to ERROR.
@ -175,9 +190,12 @@ class TaskUtils(object):
id=loadbalancer_id,
provisioning_status=constants.ERROR)
except Exception as e:
LOG.error("Failed to update load balancer %(lb)s "
"provisioning status to ERROR due to: "
"%(except)s", {'lb': loadbalancer_id, 'except': str(e)})
# Reraise for tenacity
with excutils.save_and_reraise_exception():
LOG.error("Failed to update load balancer %(lb)s "
"provisioning status to ERROR due to: "
"%(except)s", {'lb': loadbalancer_id,
'except': str(e)})
def mark_listener_prov_status_active(self, listener_id):
"""Sets a listener provisioning status to ACTIVE.
@ -214,6 +232,7 @@ class TaskUtils(object):
"to ACTIVE due to: %(except)s", {'pool': pool_id,
'except': str(e)})
@status_update_retry
def mark_loadbalancer_prov_status_active(self, loadbalancer_id):
"""Sets a load balancer provisioning status to ACTIVE.
@ -229,9 +248,12 @@ class TaskUtils(object):
id=loadbalancer_id,
provisioning_status=constants.ACTIVE)
except Exception as e:
LOG.error("Failed to update load balancer %(lb)s "
"provisioning status to ACTIVE due to: "
"%(except)s", {'lb': loadbalancer_id, 'except': str(e)})
# Reraise for tenacity
with excutils.save_and_reraise_exception():
LOG.error("Failed to update load balancer %(lb)s "
"provisioning status to ACTIVE due to: "
"%(except)s", {'lb': loadbalancer_id,
'except': str(e)})
def mark_member_prov_status_error(self, member_id):
"""Sets a member provisioning status to ERROR.

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@ -54,15 +54,22 @@ class HealthMonitorToErrorOnRevertTask(BaseLifecycleTask):
pass
def revert(self, health_mon, listeners, loadbalancer, *args, **kwargs):
self.task_utils.mark_health_mon_prov_status_error(
health_mon[constants.HEALTHMONITOR_ID])
self.task_utils.mark_pool_prov_status_active(
health_mon[constants.POOL_ID])
try:
self.task_utils.mark_health_mon_prov_status_error(
health_mon[constants.HEALTHMONITOR_ID])
self.task_utils.mark_pool_prov_status_active(
health_mon[constants.POOL_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(
loadbalancer[constants.LOADBALANCER_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
class L7PolicyToErrorOnRevertTask(BaseLifecycleTask):
@ -72,12 +79,19 @@ class L7PolicyToErrorOnRevertTask(BaseLifecycleTask):
pass
def revert(self, l7policy, listeners, loadbalancer_id, *args, **kwargs):
self.task_utils.mark_l7policy_prov_status_error(
l7policy[constants.L7POLICY_ID])
try:
self.task_utils.mark_l7policy_prov_status_error(
l7policy[constants.L7POLICY_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(loadbalancer_id)
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
class L7RuleToErrorOnRevertTask(BaseLifecycleTask):
@ -88,14 +102,21 @@ class L7RuleToErrorOnRevertTask(BaseLifecycleTask):
def revert(self, l7rule, l7policy_id, listeners, loadbalancer_id, *args,
**kwargs):
self.task_utils.mark_l7rule_prov_status_error(
l7rule[constants.L7RULE_ID])
self.task_utils.mark_l7policy_prov_status_active(l7policy_id)
try:
self.task_utils.mark_l7rule_prov_status_error(
l7rule[constants.L7RULE_ID])
self.task_utils.mark_l7policy_prov_status_active(l7policy_id)
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(
loadbalancer_id)
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
class ListenerToErrorOnRevertTask(BaseLifecycleTask):
@ -105,8 +126,15 @@ class ListenerToErrorOnRevertTask(BaseLifecycleTask):
pass
def revert(self, listener, *args, **kwargs):
self.task_utils.mark_listener_prov_status_error(
listener[constants.LISTENER_ID])
try:
self.task_utils.mark_listener_prov_status_error(
listener[constants.LISTENER_ID])
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(
listener[constants.LOADBALANCER_ID])
@ -118,9 +146,16 @@ class ListenersToErrorOnRevertTask(BaseLifecycleTask):
pass
def revert(self, listeners, *args, **kwargs):
for listener in listeners:
self.task_utils.mark_listener_prov_status_error(
listener[constants.LISTENER_ID])
try:
for listener in listeners:
self.task_utils.mark_listener_prov_status_error(
listener[constants.LISTENER_ID])
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(
listeners[0][constants.LOADBALANCER_ID])
@ -154,12 +189,19 @@ class MemberToErrorOnRevertTask(BaseLifecycleTask):
def revert(self, member, listeners, loadbalancer, pool_id, *args,
**kwargs):
self.task_utils.mark_member_prov_status_error(
member[constants.MEMBER_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
self.task_utils.mark_pool_prov_status_active(pool_id)
try:
self.task_utils.mark_member_prov_status_error(
member[constants.MEMBER_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
self.task_utils.mark_pool_prov_status_active(pool_id)
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(
loadbalancer[constants.LOADBALANCER_ID])
@ -172,13 +214,20 @@ class MembersToErrorOnRevertTask(BaseLifecycleTask):
def revert(self, members, listeners, loadbalancer, pool_id, *args,
**kwargs):
for m in members:
self.task_utils.mark_member_prov_status_error(
m[constants.MEMBER_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
self.task_utils.mark_pool_prov_status_active(pool_id)
try:
for m in members:
self.task_utils.mark_member_prov_status_error(
m[constants.MEMBER_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
self.task_utils.mark_pool_prov_status_active(pool_id)
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(
loadbalancer[constants.LOADBALANCER_ID])
@ -190,9 +239,16 @@ class PoolToErrorOnRevertTask(BaseLifecycleTask):
pass
def revert(self, pool_id, listeners, loadbalancer, *args, **kwargs):
self.task_utils.mark_pool_prov_status_error(pool_id)
try:
self.task_utils.mark_pool_prov_status_error(pool_id)
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])
except Exception:
# Catching and skipping, errors are already reported by task_utils
# and we want to ensure that mark_loadbalancer_prov_status_active
# is called to unlock the LB (it will pass or it will fail after a
# very long timeout)
pass
self.task_utils.mark_loadbalancer_prov_status_active(
loadbalancer[constants.LOADBALANCER_ID])
for listener in listeners:
self.task_utils.mark_listener_prov_status_active(
listener[constants.LISTENER_ID])

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@ -14,6 +14,7 @@
from unittest import mock
from oslo_utils import uuidutils
import tenacity
from octavia.common import constants
from octavia.controller.worker import task_utils as task_utilities
@ -183,7 +184,13 @@ class TestTaskUtils(base.TestCase):
@mock.patch('octavia.db.api.session')
@mock.patch('octavia.db.repositories.LoadBalancerRepository.update')
@mock.patch('tenacity.nap.time')
# mock LOG so we don't fill the console with log messages from
# tenacity.retry
@mock.patch('octavia.controller.worker.task_utils.LOG')
def test_mark_loadbalancer_prov_status_active(self,
mock_LOG,
mock_time,
mock_lb_repo_update,
mock_get_session):
@ -202,14 +209,42 @@ class TestTaskUtils(base.TestCase):
mock_lb_repo_update.reset_mock()
mock_get_session.side_effect = Exception('fail')
self.task_utils.mark_loadbalancer_prov_status_active(
self.assertRaises(
tenacity.RetryError,
self.task_utils.mark_loadbalancer_prov_status_active,
self.LOADBALANCER_ID)
self.assertFalse(mock_lb_repo_update.called)
# Exceptions then happy path
mock_get_session.reset_mock(side_effect=True)
mock_lb_repo_update.reset_mock()
mock_session = mock_get_session()
mock_session_context = mock_session.begin().__enter__()
mock_get_session.side_effect = [
Exception('fail'),
Exception('fail'),
Exception('fail'),
mock_session]
self.task_utils.mark_loadbalancer_prov_status_active(
self.LOADBALANCER_ID)
mock_lb_repo_update.assert_called_once_with(
mock_session_context,
id=self.LOADBALANCER_ID,
provisioning_status=constants.ACTIVE)
@mock.patch('octavia.db.api.session')
@mock.patch('octavia.db.repositories.LoadBalancerRepository.update')
@mock.patch('tenacity.nap.time')
# mock LOG so we don't fill the console with log messages from
# tenacity.retry
@mock.patch('octavia.controller.worker.task_utils.LOG')
def test_mark_loadbalancer_prov_status_error(self,
mock_LOG,
mock_time,
mock_lb_repo_update,
mock_get_session):
@ -228,10 +263,31 @@ class TestTaskUtils(base.TestCase):
mock_lb_repo_update.reset_mock()
mock_get_session.side_effect = Exception('fail')
self.assertRaises(tenacity.RetryError,
self.task_utils.mark_loadbalancer_prov_status_error,
self.LOADBALANCER_ID)
self.assertFalse(mock_lb_repo_update.called)
# Exceptions then happy path
mock_get_session.reset_mock(side_effect=True)
mock_lb_repo_update.reset_mock()
mock_session = mock_get_session()
mock_session_context = mock_session.begin().__enter__()
mock_get_session.side_effect = [
Exception('fail'),
Exception('fail'),
Exception('fail'),
mock_session]
self.task_utils.mark_loadbalancer_prov_status_error(
self.LOADBALANCER_ID)
self.assertFalse(mock_lb_repo_update.called)
mock_lb_repo_update.assert_called_once_with(
mock_session_context,
id=self.LOADBALANCER_ID,
provisioning_status=constants.ERROR)
@mock.patch('octavia.db.api.session')
@mock.patch('octavia.db.repositories.MemberRepository.update')

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@ -0,0 +1,7 @@
---
fixes:
- |
Fixed an issue with load balancers stuck in a ``PENDING_*`` state during
database outages. Now when a task fails in Octavia, it retries to update
the ``provisioning_status`` of the load balancer until the database is back
(or it gives up after a really long timeout - around 2h45)