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OpenStack Study: db.py**** CubicPower OpenStack Study ****
# # 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. from oslo.config import cfg import six from nova import conductor from nova import context from nova.openstack.common.gettextutils import _ from nova.openstack.common import log as logging from nova.openstack.common import timeutils from nova.servicegroup import api CONF = cfg.CONF CONF.import_opt('service_down_time', 'nova.service') LOG = logging.getLogger(__name__)
**** CubicPower OpenStack Study **** class DbDriver(api.ServiceGroupDriver):
**** CubicPower OpenStack Study **** def __init__(self, *args, **kwargs): self.db_allowed = kwargs.get('db_allowed', True) self.conductor_api = conductor.API(use_local=self.db_allowed)
**** CubicPower OpenStack Study **** def join(self, member_id, group_id, service=None): """Join the given service with it's group.""" msg = _('DB_Driver: join new ServiceGroup member %(member_id)s to ' 'the %(group_id)s group, service = %(service)s') LOG.debug(msg, {'member_id': member_id, 'group_id': group_id, 'service': service}) if service is None: raise RuntimeError(_('service is a mandatory argument for DB based' ' ServiceGroup driver')) report_interval = service.report_interval if report_interval: service.tg.add_timer(report_interval, self._report_state, api.INITIAL_REPORTING_DELAY, service)
**** CubicPower OpenStack Study **** def is_up(self, service_ref): """Moved from nova.utils Check whether a service is up based on last heartbeat. """ last_heartbeat = service_ref['updated_at'] or service_ref['created_at'] if isinstance(last_heartbeat, six.string_types): # NOTE(russellb) If this service_ref came in over rpc via # conductor, then the timestamp will be a string and needs to be # converted back to a datetime. last_heartbeat = timeutils.parse_strtime(last_heartbeat) else: # Objects have proper UTC timezones, but the timeutils comparison # below does not (and will fail) last_heartbeat = last_heartbeat.replace(tzinfo=None) # Timestamps in DB are UTC. elapsed = timeutils.delta_seconds(last_heartbeat, timeutils.utcnow()) LOG.debug('DB_Driver.is_up last_heartbeat = %(lhb)s elapsed = %(el)s', {'lhb': str(last_heartbeat), 'el': str(elapsed)}) return abs(elapsed) <= CONF.service_down_time
**** CubicPower OpenStack Study **** def get_all(self, group_id): """Returns ALL members of the given group """ LOG.debug(_('DB_Driver: get_all members of the %s group') % group_id) rs = [] ctxt = context.get_admin_context() services = self.conductor_api.service_get_all_by_topic(ctxt, group_id) for service in services: if self.is_up(service): rs.append(service['host']) return rs
**** CubicPower OpenStack Study **** def _report_state(self, service): """Update the state of this service in the datastore.""" ctxt = context.get_admin_context() state_catalog = {} try: report_count = service.service_ref['report_count'] + 1 state_catalog['report_count'] = report_count service.service_ref = self.conductor_api.service_update(ctxt, service.service_ref, state_catalog) # TODO(termie): make this pattern be more elegant. if getattr(service, 'model_disconnected', False): service.model_disconnected = False LOG.error(_('Recovered model server connection!')) # TODO(vish): this should probably only catch connection errors except Exception: # pylint: disable=W0702 if not getattr(service, 'model_disconnected', False): service.model_disconnected = True LOG.exception(_('model server went away'))
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