From 931f0af2e35b68c4ca40dd8e323bf07d74f48083 Mon Sep 17 00:00:00 2001 From: Terry Wilson Date: Thu, 26 Jan 2023 08:37:24 -0600 Subject: [PATCH] Never raise an exception in notify() notify() is called from python-ovs code which is not built to recover from an exception in this user-overriden code. If there is an exception (e.g. the DB server is down when we process the hash ring), this exception can cause an unrecoverable error in processing OVSDB messages, rendering the neutron worker useless. Change-Id: I5f703d82175d71a222c76df37a82b5ccad890d14 (cherry picked from commit 67e616b2380d6549308a15077b2043721dbea5d0) --- .../ovn/mech_driver/ovsdb/ovsdb_monitor.py | 64 ++++++++++--------- 1 file changed, 34 insertions(+), 30 deletions(-) diff --git a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py index 8b95b06d8fe..7214485599a 100644 --- a/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py +++ b/neutron/plugins/ml2/drivers/ovn/mech_driver/ovsdb/ovsdb_monitor.py @@ -720,39 +720,43 @@ class OvnIdlDistributedLock(BaseOvnIdl): self.driver.agent_chassis_table = 'Chassis_Private' def notify(self, event, row, updates=None): - self.handle_db_schema_changes(event, row) - self.notify_handler.notify(event, row, updates, global_=True) try: - target_node = self._hash_ring.get_node(str(row.uuid)) - except exceptions.HashRingIsEmpty as e: - LOG.error('HashRing is empty, error: %s', e) - return - if target_node != self._node_uuid: - return - - # If the worker hasn't been health checked by the maintenance - # thread (see bug #1834498), indicate that it's alive here - time_now = timeutils.utcnow() - touch_timeout = time_now - datetime.timedelta( - seconds=ovn_const.HASH_RING_TOUCH_INTERVAL) - if not self._last_touch or touch_timeout >= self._last_touch: - # NOTE(lucasagomes): Guard the db operation with an exception - # handler. If heartbeating fails for whatever reason, log - # the error and continue with processing the event + self.handle_db_schema_changes(event, row) + self.notify_handler.notify(event, row, updates, global_=True) try: - ctx = neutron_context.get_admin_context() - ovn_hash_ring_db.touch_node(ctx, self._node_uuid) - self._last_touch = time_now - except Exception: - LOG.exception('Hash Ring node %s failed to heartbeat', - self._node_uuid) + target_node = self._hash_ring.get_node(str(row.uuid)) + except exceptions.HashRingIsEmpty as e: + LOG.error('HashRing is empty, error: %s', e) + return + if target_node != self._node_uuid: + return - LOG.debug('Hash Ring: Node %(node)s (host: %(hostname)s) ' - 'handling event "%(event)s" for row %(row)s ' - '(table: %(table)s)', - {'node': self._node_uuid, 'hostname': CONF.host, - 'event': event, 'row': row.uuid, 'table': row._table.name}) - self.notify_handler.notify(event, row, updates) + # If the worker hasn't been health checked by the maintenance + # thread (see bug #1834498), indicate that it's alive here + time_now = timeutils.utcnow() + touch_timeout = time_now - datetime.timedelta( + seconds=ovn_const.HASH_RING_TOUCH_INTERVAL) + if not self._last_touch or touch_timeout >= self._last_touch: + # NOTE(lucasagomes): Guard the db operation with an exception + # handler. If heartbeating fails for whatever reason, log + # the error and continue with processing the event + try: + ctx = neutron_context.get_admin_context() + ovn_hash_ring_db.touch_node(ctx, self._node_uuid) + self._last_touch = time_now + except Exception: + LOG.exception('Hash Ring node %s failed to heartbeat', + self._node_uuid) + + LOG.debug('Hash Ring: Node %(node)s (host: %(hostname)s) ' + 'handling event "%(event)s" for row %(row)s ' + '(table: %(table)s)', + {'node': self._node_uuid, 'hostname': CONF.host, + 'event': event, 'row': row.uuid, + 'table': row._table.name}) + self.notify_handler.notify(event, row, updates) + except Exception as e: + LOG.exception(e) @abc.abstractmethod def post_connect(self):