vmware-nsx/quantum/openstack/common/rpc/impl_zmq.py
Zhongyue Luo 0ad3326409 Update Oslo rpc
Updated the rpc module for import order fix

Change-Id: I09332425827778672dc232b15ebefd9f9a6dd34a
2013-01-22 10:28:03 +08:00

798 lines
25 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2011 Cloudscaling Group, 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 os
import pprint
import socket
import string
import sys
import types
import uuid
import eventlet
import greenlet
from quantum.openstack.common import cfg
from quantum.openstack.common.gettextutils import _
from quantum.openstack.common import importutils
from quantum.openstack.common import jsonutils
from quantum.openstack.common import processutils as utils
from quantum.openstack.common.rpc import common as rpc_common
zmq = importutils.try_import('eventlet.green.zmq')
# for convenience, are not modified.
pformat = pprint.pformat
Timeout = eventlet.timeout.Timeout
LOG = rpc_common.LOG
RemoteError = rpc_common.RemoteError
RPCException = rpc_common.RPCException
zmq_opts = [
cfg.StrOpt('rpc_zmq_bind_address', default='*',
help='ZeroMQ bind address. Should be a wildcard (*), '
'an ethernet interface, or IP. '
'The "host" option should point or resolve to this '
'address.'),
# The module.Class to use for matchmaking.
cfg.StrOpt(
'rpc_zmq_matchmaker',
default=('quantum.openstack.common.rpc.'
'matchmaker.MatchMakerLocalhost'),
help='MatchMaker driver',
),
# The following port is unassigned by IANA as of 2012-05-21
cfg.IntOpt('rpc_zmq_port', default=9501,
help='ZeroMQ receiver listening port'),
cfg.IntOpt('rpc_zmq_contexts', default=1,
help='Number of ZeroMQ contexts, defaults to 1'),
cfg.IntOpt('rpc_zmq_topic_backlog', default=None,
help='Maximum number of ingress messages to locally buffer '
'per topic. Default is unlimited.'),
cfg.StrOpt('rpc_zmq_ipc_dir', default='/var/run/openstack',
help='Directory for holding IPC sockets'),
cfg.StrOpt('rpc_zmq_host', default=socket.gethostname(),
help='Name of this node. Must be a valid hostname, FQDN, or '
'IP address. Must match "host" option, if running Nova.')
]
CONF = cfg.CONF
CONF.register_opts(zmq_opts)
ZMQ_CTX = None # ZeroMQ Context, must be global.
matchmaker = None # memoized matchmaker object
def _serialize(data):
"""
Serialization wrapper
We prefer using JSON, but it cannot encode all types.
Error if a developer passes us bad data.
"""
try:
return str(jsonutils.dumps(data, ensure_ascii=True))
except TypeError:
LOG.error(_("JSON serialization failed."))
raise
def _deserialize(data):
"""
Deserialization wrapper
"""
LOG.debug(_("Deserializing: %s"), data)
return jsonutils.loads(data)
class ZmqSocket(object):
"""
A tiny wrapper around ZeroMQ to simplify the send/recv protocol
and connection management.
Can be used as a Context (supports the 'with' statement).
"""
def __init__(self, addr, zmq_type, bind=True, subscribe=None):
self.sock = _get_ctxt().socket(zmq_type)
self.addr = addr
self.type = zmq_type
self.subscriptions = []
# Support failures on sending/receiving on wrong socket type.
self.can_recv = zmq_type in (zmq.PULL, zmq.SUB)
self.can_send = zmq_type in (zmq.PUSH, zmq.PUB)
self.can_sub = zmq_type in (zmq.SUB, )
# Support list, str, & None for subscribe arg (cast to list)
do_sub = {
list: subscribe,
str: [subscribe],
type(None): []
}[type(subscribe)]
for f in do_sub:
self.subscribe(f)
str_data = {'addr': addr, 'type': self.socket_s(),
'subscribe': subscribe, 'bind': bind}
LOG.debug(_("Connecting to %(addr)s with %(type)s"), str_data)
LOG.debug(_("-> Subscribed to %(subscribe)s"), str_data)
LOG.debug(_("-> bind: %(bind)s"), str_data)
try:
if bind:
self.sock.bind(addr)
else:
self.sock.connect(addr)
except Exception:
raise RPCException(_("Could not open socket."))
def socket_s(self):
"""Get socket type as string."""
t_enum = ('PUSH', 'PULL', 'PUB', 'SUB', 'REP', 'REQ', 'ROUTER',
'DEALER')
return dict(map(lambda t: (getattr(zmq, t), t), t_enum))[self.type]
def subscribe(self, msg_filter):
"""Subscribe."""
if not self.can_sub:
raise RPCException("Cannot subscribe on this socket.")
LOG.debug(_("Subscribing to %s"), msg_filter)
try:
self.sock.setsockopt(zmq.SUBSCRIBE, msg_filter)
except Exception:
return
self.subscriptions.append(msg_filter)
def unsubscribe(self, msg_filter):
"""Unsubscribe."""
if msg_filter not in self.subscriptions:
return
self.sock.setsockopt(zmq.UNSUBSCRIBE, msg_filter)
self.subscriptions.remove(msg_filter)
def close(self):
if self.sock is None or self.sock.closed:
return
# We must unsubscribe, or we'll leak descriptors.
if len(self.subscriptions) > 0:
for f in self.subscriptions:
try:
self.sock.setsockopt(zmq.UNSUBSCRIBE, f)
except Exception:
pass
self.subscriptions = []
try:
# Default is to linger
self.sock.close()
except Exception:
# While this is a bad thing to happen,
# it would be much worse if some of the code calling this
# were to fail. For now, lets log, and later evaluate
# if we can safely raise here.
LOG.error("ZeroMQ socket could not be closed.")
self.sock = None
def recv(self):
if not self.can_recv:
raise RPCException(_("You cannot recv on this socket."))
return self.sock.recv_multipart()
def send(self, data):
if not self.can_send:
raise RPCException(_("You cannot send on this socket."))
self.sock.send_multipart(data)
class ZmqClient(object):
"""Client for ZMQ sockets."""
def __init__(self, addr, socket_type=None, bind=False):
if socket_type is None:
socket_type = zmq.PUSH
self.outq = ZmqSocket(addr, socket_type, bind=bind)
def cast(self, msg_id, topic, data, serialize=True, force_envelope=False):
if serialize:
data = rpc_common.serialize_msg(data, force_envelope)
self.outq.send([str(msg_id), str(topic), str('cast'),
_serialize(data)])
def close(self):
self.outq.close()
class RpcContext(rpc_common.CommonRpcContext):
"""Context that supports replying to a rpc.call."""
def __init__(self, **kwargs):
self.replies = []
super(RpcContext, self).__init__(**kwargs)
def deepcopy(self):
values = self.to_dict()
values['replies'] = self.replies
return self.__class__(**values)
def reply(self, reply=None, failure=None, ending=False):
if ending:
return
self.replies.append(reply)
@classmethod
def marshal(self, ctx):
ctx_data = ctx.to_dict()
return _serialize(ctx_data)
@classmethod
def unmarshal(self, data):
return RpcContext.from_dict(_deserialize(data))
class InternalContext(object):
"""Used by ConsumerBase as a private context for - methods."""
def __init__(self, proxy):
self.proxy = proxy
self.msg_waiter = None
def _get_response(self, ctx, proxy, topic, data):
"""Process a curried message and cast the result to topic."""
LOG.debug(_("Running func with context: %s"), ctx.to_dict())
data.setdefault('version', None)
data.setdefault('args', {})
try:
result = proxy.dispatch(
ctx, data['version'], data['method'], **data['args'])
return ConsumerBase.normalize_reply(result, ctx.replies)
except greenlet.GreenletExit:
# ignore these since they are just from shutdowns
pass
except rpc_common.ClientException, e:
LOG.debug(_("Expected exception during message handling (%s)") %
e._exc_info[1])
return {'exc':
rpc_common.serialize_remote_exception(e._exc_info,
log_failure=False)}
except Exception:
LOG.error(_("Exception during message handling"))
return {'exc':
rpc_common.serialize_remote_exception(sys.exc_info())}
def reply(self, ctx, proxy,
msg_id=None, context=None, topic=None, msg=None):
"""Reply to a casted call."""
# Our real method is curried into msg['args']
child_ctx = RpcContext.unmarshal(msg[0])
response = ConsumerBase.normalize_reply(
self._get_response(child_ctx, proxy, topic, msg[1]),
ctx.replies)
LOG.debug(_("Sending reply"))
cast(CONF, ctx, topic, {
'method': '-process_reply',
'args': {
'msg_id': msg_id,
'response': response
}
})
class ConsumerBase(object):
"""Base Consumer."""
def __init__(self):
self.private_ctx = InternalContext(None)
@classmethod
def normalize_reply(self, result, replies):
#TODO(ewindisch): re-evaluate and document this method.
if isinstance(result, types.GeneratorType):
return list(result)
elif replies:
return replies
else:
return [result]
def process(self, style, target, proxy, ctx, data):
# Method starting with - are
# processed internally. (non-valid method name)
method = data['method']
# Internal method
# uses internal context for safety.
if data['method'][0] == '-':
# For reply / process_reply
method = method[1:]
if method == 'reply':
self.private_ctx.reply(ctx, proxy, **data['args'])
return
data.setdefault('version', None)
data.setdefault('args', {})
proxy.dispatch(ctx, data['version'],
data['method'], **data['args'])
class ZmqBaseReactor(ConsumerBase):
"""
A consumer class implementing a
centralized casting broker (PULL-PUSH)
for RoundRobin requests.
"""
def __init__(self, conf):
super(ZmqBaseReactor, self).__init__()
self.mapping = {}
self.proxies = {}
self.threads = []
self.sockets = []
self.subscribe = {}
self.pool = eventlet.greenpool.GreenPool(conf.rpc_thread_pool_size)
def register(self, proxy, in_addr, zmq_type_in, out_addr=None,
zmq_type_out=None, in_bind=True, out_bind=True,
subscribe=None):
LOG.info(_("Registering reactor"))
if zmq_type_in not in (zmq.PULL, zmq.SUB):
raise RPCException("Bad input socktype")
# Items push in.
inq = ZmqSocket(in_addr, zmq_type_in, bind=in_bind,
subscribe=subscribe)
self.proxies[inq] = proxy
self.sockets.append(inq)
LOG.info(_("In reactor registered"))
if not out_addr:
return
if zmq_type_out not in (zmq.PUSH, zmq.PUB):
raise RPCException("Bad output socktype")
# Items push out.
outq = ZmqSocket(out_addr, zmq_type_out, bind=out_bind)
self.mapping[inq] = outq
self.mapping[outq] = inq
self.sockets.append(outq)
LOG.info(_("Out reactor registered"))
def consume_in_thread(self):
def _consume(sock):
LOG.info(_("Consuming socket"))
while True:
self.consume(sock)
for k in self.proxies.keys():
self.threads.append(
self.pool.spawn(_consume, k)
)
def wait(self):
for t in self.threads:
t.wait()
def close(self):
for s in self.sockets:
s.close()
for t in self.threads:
t.kill()
class ZmqProxy(ZmqBaseReactor):
"""
A consumer class implementing a
topic-based proxy, forwarding to
IPC sockets.
"""
def __init__(self, conf):
super(ZmqProxy, self).__init__(conf)
self.topic_proxy = {}
def consume(self, sock):
ipc_dir = CONF.rpc_zmq_ipc_dir
#TODO(ewindisch): use zero-copy (i.e. references, not copying)
data = sock.recv()
msg_id, topic, style, in_msg = data
topic = topic.split('.', 1)[0]
LOG.debug(_("CONSUMER GOT %s"), ' '.join(map(pformat, data)))
# Handle zmq_replies magic
if topic.startswith('fanout~'):
sock_type = zmq.PUB
elif topic.startswith('zmq_replies'):
sock_type = zmq.PUB
inside = rpc_common.deserialize_msg(_deserialize(in_msg))
msg_id = inside[-1]['args']['msg_id']
response = inside[-1]['args']['response']
LOG.debug(_("->response->%s"), response)
data = [str(msg_id), _serialize(response)]
else:
sock_type = zmq.PUSH
if not topic in self.topic_proxy:
def publisher(waiter):
LOG.info(_("Creating proxy for topic: %s"), topic)
try:
out_sock = ZmqSocket("ipc://%s/zmq_topic_%s" %
(ipc_dir, topic),
sock_type, bind=True)
except RPCException:
waiter.send_exception(*sys.exc_info())
return
self.topic_proxy[topic] = eventlet.queue.LightQueue(
CONF.rpc_zmq_topic_backlog)
self.sockets.append(out_sock)
# It takes some time for a pub socket to open,
# before we can have any faith in doing a send() to it.
if sock_type == zmq.PUB:
eventlet.sleep(.5)
waiter.send(True)
while(True):
data = self.topic_proxy[topic].get()
out_sock.send(data)
LOG.debug(_("ROUTER RELAY-OUT SUCCEEDED %(data)s") %
{'data': data})
wait_sock_creation = eventlet.event.Event()
eventlet.spawn(publisher, wait_sock_creation)
try:
wait_sock_creation.wait()
except RPCException:
LOG.error(_("Topic socket file creation failed."))
return
try:
self.topic_proxy[topic].put_nowait(data)
LOG.debug(_("ROUTER RELAY-OUT QUEUED %(data)s") %
{'data': data})
except eventlet.queue.Full:
LOG.error(_("Local per-topic backlog buffer full for topic "
"%(topic)s. Dropping message.") % {'topic': topic})
def consume_in_thread(self):
"""Runs the ZmqProxy service"""
ipc_dir = CONF.rpc_zmq_ipc_dir
consume_in = "tcp://%s:%s" % \
(CONF.rpc_zmq_bind_address,
CONF.rpc_zmq_port)
consumption_proxy = InternalContext(None)
if not os.path.isdir(ipc_dir):
try:
utils.execute('mkdir', '-p', ipc_dir, run_as_root=True)
utils.execute('chown', "%s:%s" % (os.getuid(), os.getgid()),
ipc_dir, run_as_root=True)
utils.execute('chmod', '750', ipc_dir, run_as_root=True)
except utils.ProcessExecutionError:
LOG.error(_("Could not create IPC directory %s") %
(ipc_dir, ))
raise
try:
self.register(consumption_proxy,
consume_in,
zmq.PULL,
out_bind=True)
except zmq.ZMQError:
LOG.error(_("Could not create ZeroMQ receiver daemon. "
"Socket may already be in use."))
raise
super(ZmqProxy, self).consume_in_thread()
class ZmqReactor(ZmqBaseReactor):
"""
A consumer class implementing a
consumer for messages. Can also be
used as a 1:1 proxy
"""
def __init__(self, conf):
super(ZmqReactor, self).__init__(conf)
def consume(self, sock):
#TODO(ewindisch): use zero-copy (i.e. references, not copying)
data = sock.recv()
LOG.debug(_("CONSUMER RECEIVED DATA: %s"), data)
if sock in self.mapping:
LOG.debug(_("ROUTER RELAY-OUT %(data)s") % {
'data': data})
self.mapping[sock].send(data)
return
msg_id, topic, style, in_msg = data
ctx, request = rpc_common.deserialize_msg(_deserialize(in_msg))
ctx = RpcContext.unmarshal(ctx)
proxy = self.proxies[sock]
self.pool.spawn_n(self.process, style, topic,
proxy, ctx, request)
class Connection(rpc_common.Connection):
"""Manages connections and threads."""
def __init__(self, conf):
self.reactor = ZmqReactor(conf)
def create_consumer(self, topic, proxy, fanout=False):
# Only consume on the base topic name.
topic = topic.split('.', 1)[0]
LOG.info(_("Create Consumer for topic (%(topic)s)") %
{'topic': topic})
# Subscription scenarios
if fanout:
subscribe = ('', fanout)[type(fanout) == str]
sock_type = zmq.SUB
topic = 'fanout~' + topic
else:
sock_type = zmq.PULL
subscribe = None
# Receive messages from (local) proxy
inaddr = "ipc://%s/zmq_topic_%s" % \
(CONF.rpc_zmq_ipc_dir, topic)
LOG.debug(_("Consumer is a zmq.%s"),
['PULL', 'SUB'][sock_type == zmq.SUB])
self.reactor.register(proxy, inaddr, sock_type,
subscribe=subscribe, in_bind=False)
def close(self):
self.reactor.close()
def wait(self):
self.reactor.wait()
def consume_in_thread(self):
self.reactor.consume_in_thread()
def _cast(addr, context, msg_id, topic, msg, timeout=None, serialize=True,
force_envelope=False):
timeout_cast = timeout or CONF.rpc_cast_timeout
payload = [RpcContext.marshal(context), msg]
with Timeout(timeout_cast, exception=rpc_common.Timeout):
try:
conn = ZmqClient(addr)
# assumes cast can't return an exception
conn.cast(msg_id, topic, payload, serialize, force_envelope)
except zmq.ZMQError:
raise RPCException("Cast failed. ZMQ Socket Exception")
finally:
if 'conn' in vars():
conn.close()
def _call(addr, context, msg_id, topic, msg, timeout=None,
serialize=True, force_envelope=False):
# timeout_response is how long we wait for a response
timeout = timeout or CONF.rpc_response_timeout
# The msg_id is used to track replies.
msg_id = uuid.uuid4().hex
# Replies always come into the reply service.
reply_topic = "zmq_replies.%s" % CONF.rpc_zmq_host
LOG.debug(_("Creating payload"))
# Curry the original request into a reply method.
mcontext = RpcContext.marshal(context)
payload = {
'method': '-reply',
'args': {
'msg_id': msg_id,
'context': mcontext,
'topic': reply_topic,
'msg': [mcontext, msg]
}
}
LOG.debug(_("Creating queue socket for reply waiter"))
# Messages arriving async.
# TODO(ewindisch): have reply consumer with dynamic subscription mgmt
with Timeout(timeout, exception=rpc_common.Timeout):
try:
msg_waiter = ZmqSocket(
"ipc://%s/zmq_topic_zmq_replies" % CONF.rpc_zmq_ipc_dir,
zmq.SUB, subscribe=msg_id, bind=False
)
LOG.debug(_("Sending cast"))
_cast(addr, context, msg_id, topic, payload,
serialize=serialize, force_envelope=force_envelope)
LOG.debug(_("Cast sent; Waiting reply"))
# Blocks until receives reply
msg = msg_waiter.recv()
LOG.debug(_("Received message: %s"), msg)
LOG.debug(_("Unpacking response"))
responses = _deserialize(msg[-1])
# ZMQError trumps the Timeout error.
except zmq.ZMQError:
raise RPCException("ZMQ Socket Error")
finally:
if 'msg_waiter' in vars():
msg_waiter.close()
# It seems we don't need to do all of the following,
# but perhaps it would be useful for multicall?
# One effect of this is that we're checking all
# responses for Exceptions.
for resp in responses:
if isinstance(resp, types.DictType) and 'exc' in resp:
raise rpc_common.deserialize_remote_exception(CONF, resp['exc'])
return responses[-1]
def _multi_send(method, context, topic, msg, timeout=None, serialize=True,
force_envelope=False):
"""
Wraps the sending of messages,
dispatches to the matchmaker and sends
message to all relevant hosts.
"""
conf = CONF
LOG.debug(_("%(msg)s") % {'msg': ' '.join(map(pformat, (topic, msg)))})
queues = _get_matchmaker().queues(topic)
LOG.debug(_("Sending message(s) to: %s"), queues)
# Don't stack if we have no matchmaker results
if len(queues) == 0:
LOG.warn(_("No matchmaker results. Not casting."))
# While not strictly a timeout, callers know how to handle
# this exception and a timeout isn't too big a lie.
raise rpc_common.Timeout, "No match from matchmaker."
# This supports brokerless fanout (addresses > 1)
for queue in queues:
(_topic, ip_addr) = queue
_addr = "tcp://%s:%s" % (ip_addr, conf.rpc_zmq_port)
if method.__name__ == '_cast':
eventlet.spawn_n(method, _addr, context,
_topic, _topic, msg, timeout, serialize,
force_envelope)
return
return method(_addr, context, _topic, _topic, msg, timeout,
serialize, force_envelope)
def create_connection(conf, new=True):
return Connection(conf)
def multicall(conf, *args, **kwargs):
"""Multiple calls."""
return _multi_send(_call, *args, **kwargs)
def call(conf, *args, **kwargs):
"""Send a message, expect a response."""
data = _multi_send(_call, *args, **kwargs)
return data[-1]
def cast(conf, *args, **kwargs):
"""Send a message expecting no reply."""
_multi_send(_cast, *args, **kwargs)
def fanout_cast(conf, context, topic, msg, **kwargs):
"""Send a message to all listening and expect no reply."""
# NOTE(ewindisch): fanout~ is used because it avoid splitting on .
# and acts as a non-subtle hint to the matchmaker and ZmqProxy.
_multi_send(_cast, context, 'fanout~' + str(topic), msg, **kwargs)
def notify(conf, context, topic, msg, **kwargs):
"""
Send notification event.
Notifications are sent to topic-priority.
This differs from the AMQP drivers which send to topic.priority.
"""
# NOTE(ewindisch): dot-priority in rpc notifier does not
# work with our assumptions.
topic.replace('.', '-')
kwargs['serialize'] = kwargs.pop('envelope')
kwargs['force_envelope'] = True
cast(conf, context, topic, msg, **kwargs)
def cleanup():
"""Clean up resources in use by implementation."""
global ZMQ_CTX
if ZMQ_CTX:
ZMQ_CTX.term()
ZMQ_CTX = None
global matchmaker
matchmaker = None
def _get_ctxt():
if not zmq:
raise ImportError("Failed to import eventlet.green.zmq")
global ZMQ_CTX
if not ZMQ_CTX:
ZMQ_CTX = zmq.Context(CONF.rpc_zmq_contexts)
return ZMQ_CTX
def _get_matchmaker():
global matchmaker
if not matchmaker:
# rpc_zmq_matchmaker should be set to a 'module.Class'
mm_path = CONF.rpc_zmq_matchmaker.split('.')
mm_module = '.'.join(mm_path[:-1])
mm_class = mm_path[-1]
# Only initialize a class.
if mm_path[-1][0] not in string.ascii_uppercase:
LOG.error(_("Matchmaker could not be loaded.\n"
"rpc_zmq_matchmaker is not a class."))
raise RPCException(_("Error loading Matchmaker."))
mm_impl = importutils.import_module(mm_module)
mm_constructor = getattr(mm_impl, mm_class)
matchmaker = mm_constructor()
return matchmaker