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Diffstat (limited to 'openstack/common/rpc/impl_qpid.py')
| -rw-r--r-- | openstack/common/rpc/impl_qpid.py | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/openstack/common/rpc/impl_qpid.py b/openstack/common/rpc/impl_qpid.py new file mode 100644 index 0000000..3c46309 --- /dev/null +++ b/openstack/common/rpc/impl_qpid.py @@ -0,0 +1,580 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright 2011 OpenStack LLC +# Copyright 2011 - 2012, Red Hat, Inc. +# +# 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. + +import functools +import itertools +import json +import logging +import time +import uuid + +import eventlet +import greenlet +import qpid.messaging +import qpid.messaging.exceptions + +from openstack.common import cfg +from openstack.common.gettextutils import _ +from openstack.common.rpc import amqp as rpc_amqp +from openstack.common.rpc import common as rpc_common + +LOG = logging.getLogger(__name__) + +qpid_opts = [ + cfg.StrOpt('qpid_hostname', + default='localhost', + help='Qpid broker hostname'), + cfg.StrOpt('qpid_port', + default='5672', + help='Qpid broker port'), + cfg.StrOpt('qpid_username', + default='', + help='Username for qpid connection'), + cfg.StrOpt('qpid_password', + default='', + help='Password for qpid connection'), + cfg.StrOpt('qpid_sasl_mechanisms', + default='', + help='Space separated list of SASL mechanisms to use for auth'), + cfg.BoolOpt('qpid_reconnect', + default=True, + help='Automatically reconnect'), + cfg.IntOpt('qpid_reconnect_timeout', + default=0, + help='Reconnection timeout in seconds'), + cfg.IntOpt('qpid_reconnect_limit', + default=0, + help='Max reconnections before giving up'), + cfg.IntOpt('qpid_reconnect_interval_min', + default=0, + help='Minimum seconds between reconnection attempts'), + cfg.IntOpt('qpid_reconnect_interval_max', + default=0, + help='Maximum seconds between reconnection attempts'), + cfg.IntOpt('qpid_reconnect_interval', + default=0, + help='Equivalent to setting max and min to the same value'), + cfg.IntOpt('qpid_heartbeat', + default=5, + help='Seconds between connection keepalive heartbeats'), + cfg.StrOpt('qpid_protocol', + default='tcp', + help="Transport to use, either 'tcp' or 'ssl'"), + cfg.BoolOpt('qpid_tcp_nodelay', + default=True, + help='Disable Nagle algorithm'), + ] + +cfg.CONF.register_opts(qpid_opts) + + +class ConsumerBase(object): + """Consumer base class.""" + + def __init__(self, session, callback, node_name, node_opts, + link_name, link_opts): + """Declare a queue on an amqp session. + + 'session' is the amqp session to use + 'callback' is the callback to call when messages are received + 'node_name' is the first part of the Qpid address string, before ';' + 'node_opts' will be applied to the "x-declare" section of "node" + in the address string. + 'link_name' goes into the "name" field of the "link" in the address + string + 'link_opts' will be applied to the "x-declare" section of "link" + in the address string. + """ + self.callback = callback + self.receiver = None + self.session = None + + addr_opts = { + "create": "always", + "node": { + "type": "topic", + "x-declare": { + "durable": True, + "auto-delete": True, + }, + }, + "link": { + "name": link_name, + "durable": True, + "x-declare": { + "durable": False, + "auto-delete": True, + "exclusive": False, + }, + }, + } + addr_opts["node"]["x-declare"].update(node_opts) + addr_opts["link"]["x-declare"].update(link_opts) + + self.address = "%s ; %s" % (node_name, json.dumps(addr_opts)) + + self.reconnect(session) + + def reconnect(self, session): + """Re-declare the receiver after a qpid reconnect""" + self.session = session + self.receiver = session.receiver(self.address) + self.receiver.capacity = 1 + + def consume(self): + """Fetch the message and pass it to the callback object""" + message = self.receiver.fetch() + self.callback(message.content) + + def get_receiver(self): + return self.receiver + + +class DirectConsumer(ConsumerBase): + """Queue/consumer class for 'direct'""" + + def __init__(self, conf, session, msg_id, callback): + """Init a 'direct' queue. + + 'session' is the amqp session to use + 'msg_id' is the msg_id to listen on + 'callback' is the callback to call when messages are received + """ + + super(DirectConsumer, self).__init__(session, callback, + "%s/%s" % (msg_id, msg_id), + {"type": "direct"}, + msg_id, + {"exclusive": True}) + + +class TopicConsumer(ConsumerBase): + """Consumer class for 'topic'""" + + def __init__(self, conf, session, topic, callback, name=None): + """Init a 'topic' queue. + + :param session: the amqp session to use + :param topic: is the topic to listen on + :paramtype topic: str + :param callback: the callback to call when messages are received + :param name: optional queue name, defaults to topic + """ + + super(TopicConsumer, self).__init__(session, callback, + "%s/%s" % (conf.control_exchange, topic), {}, + name or topic, {}) + + +class FanoutConsumer(ConsumerBase): + """Consumer class for 'fanout'""" + + def __init__(self, conf, session, topic, callback): + """Init a 'fanout' queue. + + 'session' is the amqp session to use + 'topic' is the topic to listen on + 'callback' is the callback to call when messages are received + """ + + super(FanoutConsumer, self).__init__(session, callback, + "%s_fanout" % topic, + {"durable": False, "type": "fanout"}, + "%s_fanout_%s" % (topic, uuid.uuid4().hex), + {"exclusive": True}) + + +class Publisher(object): + """Base Publisher class""" + + def __init__(self, session, node_name, node_opts=None): + """Init the Publisher class with the exchange_name, routing_key, + and other options + """ + self.sender = None + self.session = session + + addr_opts = { + "create": "always", + "node": { + "type": "topic", + "x-declare": { + "durable": False, + # auto-delete isn't implemented for exchanges in qpid, + # but put in here anyway + "auto-delete": True, + }, + }, + } + if node_opts: + addr_opts["node"]["x-declare"].update(node_opts) + + self.address = "%s ; %s" % (node_name, json.dumps(addr_opts)) + + self.reconnect(session) + + def reconnect(self, session): + """Re-establish the Sender after a reconnection""" + self.sender = session.sender(self.address) + + def send(self, msg): + """Send a message""" + self.sender.send(msg) + + +class DirectPublisher(Publisher): + """Publisher class for 'direct'""" + def __init__(self, conf, session, msg_id): + """Init a 'direct' publisher.""" + super(DirectPublisher, self).__init__(session, msg_id, + {"type": "Direct"}) + + +class TopicPublisher(Publisher): + """Publisher class for 'topic'""" + def __init__(self, conf, session, topic): + """init a 'topic' publisher. + """ + super(TopicPublisher, self).__init__(session, + "%s/%s" % (conf.control_exchange, topic)) + + +class FanoutPublisher(Publisher): + """Publisher class for 'fanout'""" + def __init__(self, conf, session, topic): + """init a 'fanout' publisher. + """ + super(FanoutPublisher, self).__init__(session, + "%s_fanout" % topic, {"type": "fanout"}) + + +class NotifyPublisher(Publisher): + """Publisher class for notifications""" + def __init__(self, conf, session, topic): + """init a 'topic' publisher. + """ + super(NotifyPublisher, self).__init__(session, + "%s/%s" % (conf.control_exchange, topic), + {"durable": True}) + + +class Connection(object): + """Connection object.""" + + pool = None + + def __init__(self, conf, server_params=None): + self.session = None + self.consumers = {} + self.consumer_thread = None + self.conf = conf + + if server_params is None: + server_params = {} + + default_params = dict(hostname=self.conf.qpid_hostname, + port=self.conf.qpid_port, + username=self.conf.qpid_username, + password=self.conf.qpid_password) + + params = server_params + for key in default_params.keys(): + params.setdefault(key, default_params[key]) + + self.broker = params['hostname'] + ":" + str(params['port']) + # Create the connection - this does not open the connection + self.connection = qpid.messaging.Connection(self.broker) + + # Check if flags are set and if so set them for the connection + # before we call open + self.connection.username = params['username'] + self.connection.password = params['password'] + self.connection.sasl_mechanisms = self.conf.qpid_sasl_mechanisms + self.connection.reconnect = self.conf.qpid_reconnect + if self.conf.qpid_reconnect_timeout: + self.connection.reconnect_timeout = ( + self.conf.qpid_reconnect_timeout) + if self.conf.qpid_reconnect_limit: + self.connection.reconnect_limit = self.conf.qpid_reconnect_limit + if self.conf.qpid_reconnect_interval_max: + self.connection.reconnect_interval_max = ( + self.conf.qpid_reconnect_interval_max) + if self.conf.qpid_reconnect_interval_min: + self.connection.reconnect_interval_min = ( + self.conf.qpid_reconnect_interval_min) + if self.conf.qpid_reconnect_interval: + self.connection.reconnect_interval = ( + self.conf.qpid_reconnect_interval) + self.connection.hearbeat = self.conf.qpid_heartbeat + self.connection.protocol = self.conf.qpid_protocol + self.connection.tcp_nodelay = self.conf.qpid_tcp_nodelay + + # Open is part of reconnect - + # NOTE(WGH) not sure we need this with the reconnect flags + self.reconnect() + + def _register_consumer(self, consumer): + self.consumers[str(consumer.get_receiver())] = consumer + + def _lookup_consumer(self, receiver): + return self.consumers[str(receiver)] + + def reconnect(self): + """Handles reconnecting and re-establishing sessions and queues""" + if self.connection.opened(): + try: + self.connection.close() + except qpid.messaging.exceptions.ConnectionError: + pass + + while True: + try: + self.connection.open() + except qpid.messaging.exceptions.ConnectionError, e: + LOG.error(_('Unable to connect to AMQP server: %s'), e) + time.sleep(self.conf.qpid_reconnect_interval or 1) + else: + break + + LOG.info(_('Connected to AMQP server on %s'), self.broker) + + self.session = self.connection.session() + + for consumer in self.consumers.itervalues(): + consumer.reconnect(self.session) + + if self.consumers: + LOG.debug(_("Re-established AMQP queues")) + + def ensure(self, error_callback, method, *args, **kwargs): + while True: + try: + return method(*args, **kwargs) + except (qpid.messaging.exceptions.Empty, + qpid.messaging.exceptions.ConnectionError), e: + if error_callback: + error_callback(e) + self.reconnect() + + def close(self): + """Close/release this connection""" + self.cancel_consumer_thread() + self.connection.close() + self.connection = None + + def reset(self): + """Reset a connection so it can be used again""" + self.cancel_consumer_thread() + self.session.close() + self.session = self.connection.session() + self.consumers = {} + + def declare_consumer(self, consumer_cls, topic, callback): + """Create a Consumer using the class that was passed in and + add it to our list of consumers + """ + def _connect_error(exc): + log_info = {'topic': topic, 'err_str': str(exc)} + LOG.error(_("Failed to declare consumer for topic '%(topic)s': " + "%(err_str)s") % log_info) + + def _declare_consumer(): + consumer = consumer_cls(self.conf, self.session, topic, callback) + self._register_consumer(consumer) + return consumer + + return self.ensure(_connect_error, _declare_consumer) + + def iterconsume(self, limit=None, timeout=None): + """Return an iterator that will consume from all queues/consumers""" + + def _error_callback(exc): + if isinstance(exc, qpid.messaging.exceptions.Empty): + LOG.exception(_('Timed out waiting for RPC response: %s') % + str(exc)) + raise rpc_common.Timeout() + else: + LOG.exception(_('Failed to consume message from queue: %s') % + str(exc)) + + def _consume(): + nxt_receiver = self.session.next_receiver(timeout=timeout) + try: + self._lookup_consumer(nxt_receiver).consume() + except Exception: + LOG.exception(_("Error processing message. Skipping it.")) + + for iteration in itertools.count(0): + if limit and iteration >= limit: + raise StopIteration + yield self.ensure(_error_callback, _consume) + + def cancel_consumer_thread(self): + """Cancel a consumer thread""" + if self.consumer_thread is not None: + self.consumer_thread.kill() + try: + self.consumer_thread.wait() + except greenlet.GreenletExit: + pass + self.consumer_thread = None + + def publisher_send(self, cls, topic, msg): + """Send to a publisher based on the publisher class""" + + def _connect_error(exc): + log_info = {'topic': topic, 'err_str': str(exc)} + LOG.exception(_("Failed to publish message to topic " + "'%(topic)s': %(err_str)s") % log_info) + + def _publisher_send(): + publisher = cls(self.conf, self.session, topic) + publisher.send(msg) + + return self.ensure(_connect_error, _publisher_send) + + def declare_direct_consumer(self, topic, callback): + """Create a 'direct' queue. + In nova's use, this is generally a msg_id queue used for + responses for call/multicall + """ + self.declare_consumer(DirectConsumer, topic, callback) + + def declare_topic_consumer(self, topic, callback=None, queue_name=None): + """Create a 'topic' consumer.""" + self.declare_consumer(functools.partial(TopicConsumer, + name=queue_name, + ), + topic, callback) + + def declare_fanout_consumer(self, topic, callback): + """Create a 'fanout' consumer""" + self.declare_consumer(FanoutConsumer, topic, callback) + + def direct_send(self, msg_id, msg): + """Send a 'direct' message""" + self.publisher_send(DirectPublisher, msg_id, msg) + + def topic_send(self, topic, msg): + """Send a 'topic' message""" + self.publisher_send(TopicPublisher, topic, msg) + + def fanout_send(self, topic, msg): + """Send a 'fanout' message""" + self.publisher_send(FanoutPublisher, topic, msg) + + def notify_send(self, topic, msg, **kwargs): + """Send a notify message on a topic""" + self.publisher_send(NotifyPublisher, topic, msg) + + def consume(self, limit=None): + """Consume from all queues/consumers""" + it = self.iterconsume(limit=limit) + while True: + try: + it.next() + except StopIteration: + return + + def consume_in_thread(self): + """Consumer from all queues/consumers in a greenthread""" + def _consumer_thread(): + try: + self.consume() + except greenlet.GreenletExit: + return + if self.consumer_thread is None: + self.consumer_thread = eventlet.spawn(_consumer_thread) + return self.consumer_thread + + def create_consumer(self, topic, proxy, fanout=False): + """Create a consumer that calls a method in a proxy object""" + proxy_cb = rpc_amqp.ProxyCallback(self.conf, proxy, + rpc_amqp.get_connection_pool(self.conf, Connection)) + + if fanout: + consumer = FanoutConsumer(self.conf, self.session, topic, proxy_cb) + else: + consumer = TopicConsumer(self.conf, self.session, topic, proxy_cb) + + self._register_consumer(consumer) + + return consumer + + def create_worker(self, topic, proxy, pool_name): + """Create a worker that calls a method in a proxy object""" + proxy_cb = rpc_amqp.ProxyCallback(self.conf, proxy, + rpc_amqp.get_connection_pool(self.conf, Connection)) + + consumer = TopicConsumer(self.conf, self.session, topic, proxy_cb, + name=pool_name) + + self._register_consumer(consumer) + + return consumer + + +def create_connection(conf, new=True): + """Create a connection""" + return rpc_amqp.create_connection(conf, new, + rpc_amqp.get_connection_pool(conf, Connection)) + + +def multicall(conf, context, topic, msg, timeout=None): + """Make a call that returns multiple times.""" + return rpc_amqp.multicall(conf, context, topic, msg, timeout, + rpc_amqp.get_connection_pool(conf, Connection)) + + +def call(conf, context, topic, msg, timeout=None): + """Sends a message on a topic and wait for a response.""" + return rpc_amqp.call(conf, context, topic, msg, timeout, + rpc_amqp.get_connection_pool(conf, Connection)) + + +def cast(conf, context, topic, msg): + """Sends a message on a topic without waiting for a response.""" + return rpc_amqp.cast(conf, context, topic, msg, + rpc_amqp.get_connection_pool(conf, Connection)) + + +def fanout_cast(conf, context, topic, msg): + """Sends a message on a fanout exchange without waiting for a response.""" + return rpc_amqp.fanout_cast(conf, context, topic, msg, + rpc_amqp.get_connection_pool(conf, Connection)) + + +def cast_to_server(conf, context, server_params, topic, msg): + """Sends a message on a topic to a specific server.""" + return rpc_amqp.cast_to_server(conf, context, server_params, topic, msg, + rpc_amqp.get_connection_pool(conf, Connection)) + + +def fanout_cast_to_server(conf, context, server_params, topic, msg): + """Sends a message on a fanout exchange to a specific server.""" + return rpc_amqp.fanout_cast_to_server(conf, context, server_params, topic, + msg, rpc_amqp.get_connection_pool(conf, Connection)) + + +def notify(conf, context, topic, msg): + """Sends a notification event on a topic.""" + return rpc_amqp.notify(conf, context, topic, msg, + rpc_amqp.get_connection_pool(conf, Connection)) + + +def cleanup(): + return rpc_amqp.cleanup(Connection.pool) |