diff options
Diffstat (limited to 'nova/service.py')
| -rw-r--r-- | nova/service.py | 125 |
1 files changed, 91 insertions, 34 deletions
diff --git a/nova/service.py b/nova/service.py index 96281bc6b..870dd6ceb 100644 --- a/nova/service.py +++ b/nova/service.py @@ -28,75 +28,132 @@ from twisted.internet import defer from twisted.internet import task from twisted.application import service -from nova import datastore +from nova import db +from nova import exception from nova import flags from nova import rpc -from nova.compute import model +from nova import utils FLAGS = flags.FLAGS - flags.DEFINE_integer('report_interval', 10, 'seconds between nodes reporting state to cloud', lower_bound=1) + class Service(object, service.Service): - """Base class for workers that run on hosts""" + """Base class for workers that run on hosts.""" + + def __init__(self, host, binary, topic, manager, *args, **kwargs): + self.host = host + self.binary = binary + self.topic = topic + manager_class = utils.import_class(manager) + self.manager = manager_class(host=host, *args, **kwargs) + self.model_disconnected = False + super(Service, self).__init__(*args, **kwargs) + try: + service_ref = db.service_get_by_args(None, + self.host, + self.binary) + self.service_id = service_ref['id'] + except exception.NotFound: + self._create_service_ref() + + + def _create_service_ref(self): + service_ref = db.service_create(None, {'host': self.host, + 'binary': self.binary, + 'topic': self.topic, + 'report_count': 0}) + self.service_id = service_ref['id'] + + def __getattr__(self, key): + try: + return super(Service, self).__getattr__(key) + except AttributeError: + return getattr(self.manager, key) @classmethod def create(cls, - report_interval=None, # defaults to flag - bin_name=None, # defaults to basename of executable - topic=None): # defaults to basename - "nova-" part - """Instantiates class and passes back application object""" + host=None, + binary=None, + topic=None, + manager=None, + report_interval=None): + """Instantiates class and passes back application object. + + Args: + host, defaults to FLAGS.host + binary, defaults to basename of executable + topic, defaults to bin_name - "nova-" part + manager, defaults to FLAGS.<topic>_manager + report_interval, defaults to FLAGS.report_interval + """ + if not host: + host = FLAGS.host + if not binary: + binary = os.path.basename(inspect.stack()[-1][1]) + if not topic: + topic = binary.rpartition("nova-")[2] + if not manager: + manager = FLAGS.get('%s_manager' % topic, None) if not report_interval: - # NOTE(vish): set here because if it is set to flag in the - # parameter list, it wrongly uses the default report_interval = FLAGS.report_interval - # NOTE(vish): magic to automatically determine bin_name and topic - if not bin_name: - bin_name = os.path.basename(inspect.stack()[-1][1]) - if not topic: - topic = bin_name.rpartition("nova-")[2] - logging.warn("Starting %s node" % topic) - node_instance = cls() - + logging.warn("Starting %s node", topic) + service_obj = cls(host, binary, topic, manager) conn = rpc.Connection.instance() consumer_all = rpc.AdapterConsumer( connection=conn, - topic='%s' % topic, - proxy=node_instance) - + topic=topic, + proxy=service_obj) consumer_node = rpc.AdapterConsumer( connection=conn, - topic='%s.%s' % (topic, FLAGS.node_name), - proxy=node_instance) + topic='%s.%s' % (topic, host), + proxy=service_obj) - pulse = task.LoopingCall(node_instance.report_state, - FLAGS.node_name, - bin_name) + pulse = task.LoopingCall(service_obj.report_state) pulse.start(interval=report_interval, now=False) consumer_all.attach_to_twisted() consumer_node.attach_to_twisted() # This is the parent service that twistd will be looking for when it - # parses this file, return it so that we can get it into globals below - application = service.Application(bin_name) - node_instance.setServiceParent(application) + # parses this file, return it so that we can get it into globals. + application = service.Application(binary) + service_obj.setServiceParent(application) return application + def kill(self, context=None): + """Destroy the service object in the datastore""" + try: + db.service_destroy(context, self.service_id) + except exception.NotFound: + logging.warn("Service killed that has no database entry") + @defer.inlineCallbacks - def report_state(self, nodename, daemon): - # TODO(termie): make this pattern be more elegant. -todd + def report_state(self, context=None): + """Update the state of this service in the datastore.""" try: - record = model.Daemon(nodename, daemon) - record.heartbeat() + try: + service_ref = db.service_get(context, self.service_id) + except exception.NotFound: + logging.debug("The service database object disappeared, " + "Recreating it.") + self._create_service_ref() + service_ref = db.service_get(context, self.service_id) + + db.service_update(context, + self.service_id, + {'report_count': service_ref['report_count'] + 1}) + + # TODO(termie): make this pattern be more elegant. if getattr(self, "model_disconnected", False): self.model_disconnected = False logging.error("Recovered model server connection!") - except datastore.ConnectionError, ex: + # TODO(vish): this should probably only catch connection errors + except Exception: # pylint: disable-msg=W0702 if not getattr(self, "model_disconnected", False): self.model_disconnected = True logging.exception("model server went away") |