e72a8d5bc4
This patch simply moves the existing AMQP 1.0 driver files into a directory layout that is consistent with the other drivers. The driver unit tests are also moved to the proper test directory. There are no changes in driver functionality or API. Change-Id: I83a5d5433be8c3b317597100af69192ec5be81f1 Closes-Bug: #1579823
748 lines
31 KiB
Python
748 lines
31 KiB
Python
# Copyright 2014, Red Hat, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""
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Controller that manages the interface between the driver and the messaging
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service.
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This module defines a Controller class that is responsible for performing
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messaging-related operations (Tasks) requested by the driver, and for managing
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the connection to the messaging service. The Controller creates a background
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thread which performs all messaging operations and socket I/O. The
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Controller's messaging logic is executed in the background thread via lambda
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functions scheduled by the Controller.
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"""
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import abc
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import logging
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import threading
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import uuid
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from oslo_config import cfg
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import proton
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import pyngus
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from six import moves
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from oslo_messaging._drivers.amqp1_driver import eventloop
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from oslo_messaging._drivers.amqp1_driver import opts
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from oslo_messaging._i18n import _LE, _LI, _LW
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from oslo_messaging import exceptions
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from oslo_messaging import transport
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LOG = logging.getLogger(__name__)
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class Task(object):
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"""Perform a messaging operation via the Controller."""
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@abc.abstractmethod
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def execute(self, controller):
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"""This method will be run on the eventloop thread."""
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class Sender(pyngus.SenderEventHandler):
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"""A single outgoing link to a given address"""
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def __init__(self, address):
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self._address = address
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self._link = None
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def attach(self, connection):
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# open a link to the destination
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sname = "Producer-%s:src=%s:tgt=%s" % (uuid.uuid4().hex,
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self._address,
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self._address)
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self._link = connection.create_sender(name=sname,
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source_address=self._address,
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target_address=self._address)
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self._link.open()
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def detach(self):
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# close the link
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if self._link:
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self._link.close()
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def destroy(self):
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# drop reference to link. The link will be freed when the
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# connection is destroyed
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self._link = None
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def send(self, message, callback):
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# send message out the link, invoke callback when acked
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self._link.send(message, delivery_callback=callback)
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def sender_remote_closed(self, sender_link, pn_condition):
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LOG.debug("sender_remote_closed condition=%s", pn_condition)
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sender_link.close()
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def sender_failed(self, sender_link, error):
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"""Protocol error occurred."""
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LOG.error(_LE("Outgoing link to %(addr) failed. error=%(error)"),
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{"addr": self._address, "error": error})
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class Replies(pyngus.ReceiverEventHandler):
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"""This is the receiving link for all reply messages. Messages are routed
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to the proper Listener's incoming queue using the correlation-id header in
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the message.
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"""
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def __init__(self, connection, on_ready):
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self._correlation = {} # map of correlation-id to response queue
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self._ready = False
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self._on_ready = on_ready
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rname = "Consumer-%s:src=[dynamic]:tgt=replies" % uuid.uuid4().hex
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self._receiver = connection.create_receiver("replies",
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event_handler=self,
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name=rname)
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# capacity determines the maximum number of reply messages this link
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# can receive. As messages are received and credit is consumed, this
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# driver will 'top up' the credit back to max capacity. This number
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# should be large enough to avoid needlessly flow-controlling the
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# replies.
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self.capacity = 100 # TODO(kgiusti) guesstimate - make configurable
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self._credit = 0
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self._receiver.open()
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def detach(self):
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# close the link
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self._receiver.close()
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def destroy(self):
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# drop reference to link. Link will be freed when the connection is
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# released.
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self._receiver = None
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def ready(self):
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return self._ready
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def prepare_for_response(self, request, reply_queue):
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"""Apply a unique message identifier to this request message. This will
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be used to identify messages sent in reply. The identifier is placed
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in the 'id' field of the request message. It is expected that the
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identifier will appear in the 'correlation-id' field of the
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corresponding response message.
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"""
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request.id = uuid.uuid4().hex
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# reply is placed on reply_queue
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self._correlation[request.id] = reply_queue
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request.reply_to = self._receiver.source_address
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LOG.debug("Reply for msg id=%(id)s expected on link %(reply_to)s",
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{'id': request.id, 'reply_to': request.reply_to})
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return request.id
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def cancel_response(self, msg_id):
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"""Abort waiting for a response message. This can be used if the
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request fails and no reply is expected.
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"""
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if msg_id in self._correlation:
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del self._correlation[msg_id]
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# Pyngus ReceiverLink event callbacks:
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def receiver_active(self, receiver_link):
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"""This is a Pyngus callback, invoked by Pyngus when the receiver_link
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has transitioned to the open state and is able to receive incoming
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messages.
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"""
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self._ready = True
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self._update_credit()
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self._on_ready()
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LOG.debug("Replies expected on link %s",
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self._receiver.source_address)
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def receiver_remote_closed(self, receiver, pn_condition):
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"""This is a Pyngus callback, invoked by Pyngus when the peer of this
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receiver link has initiated closing the connection.
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"""
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# TODO(kgiusti) Log for now, possibly implement a recovery strategy if
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# necessary.
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if pn_condition:
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LOG.error(_LE("Reply subscription closed by peer: %s"),
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pn_condition)
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receiver.close()
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def receiver_failed(self, receiver_link, error):
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"""Protocol error occurred."""
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LOG.error(_LE("Link to reply queue %(addr) failed. error=%(error)"),
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{"addr": self._address, "error": error})
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def message_received(self, receiver, message, handle):
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"""This is a Pyngus callback, invoked by Pyngus when a new message
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arrives on this receiver link from the peer.
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"""
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self._credit = self._credit - 1
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self._update_credit()
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key = message.correlation_id
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if key in self._correlation:
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LOG.debug("Received response for msg id=%s", key)
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result = {"status": "OK",
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"response": message}
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self._correlation[key].put(result)
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# cleanup (only need one response per request)
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del self._correlation[key]
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receiver.message_accepted(handle)
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else:
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LOG.warning(_LW("Can't find receiver for response msg id=%s, "
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"dropping!"), key)
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receiver.message_modified(handle, True, True, None)
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def _update_credit(self):
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# ensure we have enough credit
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if self._credit < self.capacity / 2:
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self._receiver.add_capacity(self.capacity - self._credit)
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self._credit = self.capacity
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class Server(pyngus.ReceiverEventHandler):
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"""A group of links that receive messages from a set of addresses derived
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from a given target. Messages arriving on the links are placed on the
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'incoming' queue.
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"""
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def __init__(self, addresses, incoming, subscription_id):
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self._incoming = incoming
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self._addresses = addresses
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self._capacity = 500 # credit per link
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self._receivers = []
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self._id = subscription_id
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def attach(self, connection):
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"""Create receiver links over the given connection for all the
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configured addresses.
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"""
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for a in self._addresses:
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props = {"snd-settle-mode": "settled"}
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rname = "Consumer-%s:src=%s:tgt=%s" % (uuid.uuid4().hex, a, a)
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r = connection.create_receiver(source_address=a,
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target_address=a,
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event_handler=self,
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name=rname,
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properties=props)
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# TODO(kgiusti) Hardcoding credit here is sub-optimal. A better
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# approach would monitor for a back-up of inbound messages to be
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# processed by the consuming application and backpressure the
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# sender based on configured thresholds.
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r.add_capacity(self._capacity)
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r.open()
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self._receivers.append(r)
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def detach(self):
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# close the links
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for receiver in self._receivers:
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receiver.close()
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def reset(self):
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# destroy the links, but keep the addresses around since we may be
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# failing over. Since links are destroyed, this cannot be called from
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# any of the following ReceiverLink callbacks.
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for r in self._receivers:
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r.destroy()
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self._receivers = []
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# Pyngus ReceiverLink event callbacks:
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def receiver_remote_closed(self, receiver, pn_condition):
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"""This is a Pyngus callback, invoked by Pyngus when the peer of this
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receiver link has initiated closing the connection.
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"""
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if pn_condition:
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vals = {
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"addr": receiver.source_address or receiver.target_address,
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"err_msg": pn_condition
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}
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LOG.error(_LE("Server subscription %(addr)s closed "
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"by peer: %(err_msg)s"), vals)
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receiver.close()
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def receiver_failed(self, receiver_link, error):
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"""Protocol error occurred."""
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LOG.error(_LE("Listener link queue %(addr) failed. error=%(error)"),
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{"addr": self._address, "error": error})
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def message_received(self, receiver, message, handle):
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"""This is a Pyngus callback, invoked by Pyngus when a new message
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arrives on this receiver link from the peer.
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"""
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if receiver.capacity < self._capacity / 2:
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receiver.add_capacity(self._capacity - receiver.capacity)
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self._incoming.put(message)
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LOG.debug("message received: %s", message)
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receiver.message_accepted(handle)
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class Hosts(object):
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"""An order list of TransportHost addresses. Connection failover
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progresses from one host to the next. username and password come from the
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configuration and are used only if no username/password was given in the
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URL.
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"""
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def __init__(self, entries=None, default_username=None,
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default_password=None):
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if entries:
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self._entries = entries[:]
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else:
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self._entries = [transport.TransportHost(hostname="localhost",
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port=5672)]
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for entry in self._entries:
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entry.port = entry.port or 5672
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entry.username = entry.username or default_username
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entry.password = entry.password or default_password
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self._current = 0
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@property
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def current(self):
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return self._entries[self._current]
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def next(self):
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if len(self._entries) > 1:
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self._current = (self._current + 1) % len(self._entries)
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return self.current
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def __repr__(self):
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return '<Hosts ' + str(self) + '>'
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def __str__(self):
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return ", ".join(["%r" % th for th in self._entries])
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class Controller(pyngus.ConnectionEventHandler):
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"""Controls the connection to the AMQP messaging service. This object is
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the 'brains' of the driver. It maintains the logic for addressing, sending
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and receiving messages, and managing the connection. All messaging and I/O
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work is done on the Eventloop thread, allowing the driver to run
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asynchronously from the messaging clients.
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"""
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def __init__(self, hosts, default_exchange, config):
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self.processor = None
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self._socket_connection = None
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# queue of Task() objects to execute on the eventloop once the
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# connection is ready:
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self._tasks = moves.queue.Queue(maxsize=500)
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# limit the number of Task()'s to execute per call to _process_tasks().
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# This allows the eventloop main thread to return to servicing socket
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# I/O in a timely manner
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self._max_task_batch = 50
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# cache of sending links indexed by address:
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self._senders = {}
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# Servers indexed by target. Each entry is a map indexed by the
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# specific ProtonListener's identifier:
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self._servers = {}
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opt_group = cfg.OptGroup(name='oslo_messaging_amqp',
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title='AMQP 1.0 driver options')
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config.register_group(opt_group)
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config.register_opts(opts.amqp1_opts, group=opt_group)
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self.server_request_prefix = \
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config.oslo_messaging_amqp.server_request_prefix
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self.broadcast_prefix = config.oslo_messaging_amqp.broadcast_prefix
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self.group_request_prefix = \
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config.oslo_messaging_amqp.group_request_prefix
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self._container_name = config.oslo_messaging_amqp.container_name
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self.idle_timeout = config.oslo_messaging_amqp.idle_timeout
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self.trace_protocol = config.oslo_messaging_amqp.trace
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self.ssl_ca_file = config.oslo_messaging_amqp.ssl_ca_file
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self.ssl_cert_file = config.oslo_messaging_amqp.ssl_cert_file
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self.ssl_key_file = config.oslo_messaging_amqp.ssl_key_file
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self.ssl_key_password = config.oslo_messaging_amqp.ssl_key_password
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self.ssl_allow_insecure = \
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config.oslo_messaging_amqp.allow_insecure_clients
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self.sasl_mechanisms = config.oslo_messaging_amqp.sasl_mechanisms
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self.sasl_config_dir = config.oslo_messaging_amqp.sasl_config_dir
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self.sasl_config_name = config.oslo_messaging_amqp.sasl_config_name
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self.hosts = Hosts(hosts, config.oslo_messaging_amqp.username,
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config.oslo_messaging_amqp.password)
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self.separator = "."
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self.fanout_qualifier = "all"
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self.default_exchange = default_exchange
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# can't handle a request until the replies link is active, as
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# we need the peer assigned address, so need to delay any
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# processing of task queue until this is done
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self._replies = None
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# Set True when the driver is shutting down
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self._closing = False
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# only schedule one outstanding reconnect attempt at a time
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self._reconnecting = False
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self._delay = 0 # seconds between retries
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# prevent queuing up multiple requests to run _process_tasks()
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self._process_tasks_scheduled = False
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self._process_tasks_lock = threading.Lock()
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def connect(self):
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"""Connect to the messaging service."""
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self.processor = eventloop.Thread(self._container_name)
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self.processor.wakeup(lambda: self._do_connect())
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def add_task(self, task):
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"""Add a Task for execution on processor thread."""
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self._tasks.put(task)
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self._schedule_task_processing()
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def shutdown(self, timeout=None):
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"""Shutdown the messaging service."""
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LOG.info(_LI("Shutting down the AMQP 1.0 connection"))
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if self.processor:
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self.processor.wakeup(lambda: self._start_shutdown())
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LOG.debug("Waiting for eventloop to exit")
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self.processor.join(timeout)
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self._hard_reset()
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self.processor.destroy()
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self.processor = None
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LOG.debug("Eventloop exited, driver shut down")
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# The remaining methods are reserved to run from the eventloop thread only!
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# They must not be invoked directly!
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# methods executed by Tasks created by the driver:
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def request(self, target, request, result_queue, reply_expected=False):
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"""Send a request message to the given target and arrange for a
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result to be put on the result_queue. If reply_expected, the result
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will include the reply message (if successful).
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"""
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address = self._resolve(target)
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LOG.debug("Sending request for %(target)s to %(address)s",
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{'target': target, 'address': address})
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if reply_expected:
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msg_id = self._replies.prepare_for_response(request, result_queue)
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def _callback(link, handle, state, info):
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if state == pyngus.SenderLink.ACCEPTED: # message received
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if not reply_expected:
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# can wake up the sender now
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result = {"status": "OK"}
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result_queue.put(result)
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else:
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# we will wake up the sender when the reply message is
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# received. See Replies.message_received()
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pass
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else: # send failed/rejected/etc
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msg = "Message send failed: remote disposition: %s, info: %s"
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exc = exceptions.MessageDeliveryFailure(msg % (state, info))
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result = {"status": "ERROR", "error": exc}
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if reply_expected:
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# no response will be received, so cancel the correlation
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self._replies.cancel_response(msg_id)
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result_queue.put(result)
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self._send(address, request, _callback)
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def response(self, address, response):
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"""Send a response message to the client listening on 'address'.
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To prevent a misbehaving client from blocking a server indefinitely,
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the message is send asynchronously.
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"""
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LOG.debug("Sending response to %s", address)
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self._send(address, response)
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def subscribe(self, target, in_queue, subscription_id):
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"""Subscribe to messages sent to 'target', place received messages on
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'in_queue'.
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"""
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addresses = [
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self._server_address(target),
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self._broadcast_address(target),
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self._group_request_address(target)
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]
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self._subscribe(target, addresses, in_queue, subscription_id)
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def subscribe_notifications(self, target, in_queue, subscription_id):
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"""Subscribe for notifications on 'target', place received messages on
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'in_queue'.
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"""
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addresses = [self._group_request_address(target)]
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self._subscribe(target, addresses, in_queue, subscription_id)
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def _subscribe(self, target, addresses, in_queue, subscription_id):
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LOG.debug("Subscribing to %(target)s (%(addresses)s)",
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{'target': target, 'addresses': addresses})
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server = Server(addresses, in_queue, subscription_id)
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servers = self._servers.get(target)
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if servers is None:
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servers = {}
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self._servers[target] = servers
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servers[subscription_id] = server
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server.attach(self._socket_connection.connection)
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def _resolve(self, target):
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"""Return a link address for a given target."""
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if target.fanout:
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return self._broadcast_address(target)
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elif target.server:
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return self._server_address(target)
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else:
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return self._group_request_address(target)
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def _sender(self, address):
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# if we already have a sender for that address, use it
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# else establish the sender and cache it
|
|
sender = self._senders.get(address)
|
|
if sender is None:
|
|
sender = Sender(address)
|
|
sender.attach(self._socket_connection.connection)
|
|
self._senders[address] = sender
|
|
return sender
|
|
|
|
def _send(self, addr, message, callback=None, handle=None):
|
|
"""Send the message out the link addressed by 'addr'. If a
|
|
delivery_callback is given it will be invoked when the send has
|
|
completed (whether successfully or in error).
|
|
"""
|
|
address = str(addr)
|
|
message.address = address
|
|
self._sender(address).send(message, callback)
|
|
|
|
def _server_address(self, target):
|
|
return self._concatenate([self.server_request_prefix,
|
|
target.exchange or self.default_exchange,
|
|
target.topic, target.server])
|
|
|
|
def _broadcast_address(self, target):
|
|
return self._concatenate([self.broadcast_prefix,
|
|
target.exchange or self.default_exchange,
|
|
target.topic, self.fanout_qualifier])
|
|
|
|
def _group_request_address(self, target):
|
|
return self._concatenate([self.group_request_prefix,
|
|
target.exchange or self.default_exchange,
|
|
target.topic])
|
|
|
|
def _concatenate(self, items):
|
|
return self.separator.join(filter(bool, items))
|
|
|
|
# commands executed on the processor (eventloop) via 'wakeup()':
|
|
|
|
def _do_connect(self):
|
|
"""Establish connection and reply subscription on processor thread."""
|
|
host = self.hosts.current
|
|
conn_props = {'hostname': host.hostname}
|
|
if self.idle_timeout:
|
|
conn_props["idle-time-out"] = float(self.idle_timeout)
|
|
if self.trace_protocol:
|
|
conn_props["x-trace-protocol"] = self.trace_protocol
|
|
if self.ssl_ca_file:
|
|
conn_props["x-ssl-ca-file"] = self.ssl_ca_file
|
|
if self.ssl_cert_file:
|
|
# assume this connection is for a server. If client authentication
|
|
# support is developed, we'll need an explicit flag (server or
|
|
# client)
|
|
conn_props["x-ssl-server"] = True
|
|
conn_props["x-ssl-identity"] = (self.ssl_cert_file,
|
|
self.ssl_key_file,
|
|
self.ssl_key_password)
|
|
conn_props["x-ssl-allow-cleartext"] = self.ssl_allow_insecure
|
|
# SASL configuration:
|
|
if self.sasl_mechanisms:
|
|
conn_props["x-sasl-mechs"] = self.sasl_mechanisms
|
|
if self.sasl_config_dir:
|
|
conn_props["x-sasl-config-dir"] = self.sasl_config_dir
|
|
if self.sasl_config_name:
|
|
conn_props["x-sasl-config-name"] = self.sasl_config_name
|
|
|
|
self._socket_connection = self.processor.connect(host,
|
|
handler=self,
|
|
properties=conn_props)
|
|
LOG.debug("Connection initiated")
|
|
|
|
def _process_tasks(self):
|
|
"""Execute Task objects in the context of the processor thread."""
|
|
with self._process_tasks_lock:
|
|
self._process_tasks_scheduled = False
|
|
count = 0
|
|
while (not self._tasks.empty() and
|
|
count < self._max_task_batch and
|
|
self._can_process_tasks):
|
|
try:
|
|
self._tasks.get(False).execute(self)
|
|
except Exception as e:
|
|
LOG.exception(_LE("Error processing task: %s"), e)
|
|
count += 1
|
|
|
|
# if we hit _max_task_batch, resume task processing later:
|
|
if not self._tasks.empty() and self._can_process_tasks:
|
|
self._schedule_task_processing()
|
|
|
|
def _schedule_task_processing(self):
|
|
"""_process_tasks() helper: prevent queuing up multiple requests for
|
|
task processing. This method is called both by the application thread
|
|
and the processing thread.
|
|
"""
|
|
if self.processor:
|
|
with self._process_tasks_lock:
|
|
already_scheduled = self._process_tasks_scheduled
|
|
self._process_tasks_scheduled = True
|
|
if not already_scheduled:
|
|
self.processor.wakeup(lambda: self._process_tasks())
|
|
|
|
@property
|
|
def _can_process_tasks(self):
|
|
"""_process_tasks helper(): indicates that the driver is ready to
|
|
process Tasks. In order to process messaging-related tasks, the reply
|
|
queue link must be active.
|
|
"""
|
|
return (not self._closing and
|
|
self._replies and self._replies.ready())
|
|
|
|
def _start_shutdown(self):
|
|
"""Called when the application is closing the transport.
|
|
Attempt to cleanly flush/close all links.
|
|
"""
|
|
self._closing = True
|
|
if (self._socket_connection
|
|
and self._socket_connection.connection
|
|
and self._socket_connection.connection.active):
|
|
# try a clean shutdown
|
|
for sender in self._senders.values():
|
|
sender.detach()
|
|
for servers in self._servers.values():
|
|
for server in servers.values():
|
|
server.detach()
|
|
self._replies.detach()
|
|
self._socket_connection.connection.close()
|
|
else:
|
|
# don't wait for a close from the remote, may never happen
|
|
self.processor.shutdown()
|
|
|
|
# reply link active callback:
|
|
|
|
def _reply_link_ready(self):
|
|
"""Invoked when the Replies reply link has become active. At this
|
|
point, we are ready to send/receive messages (via Task processing).
|
|
"""
|
|
LOG.info(_LI("Messaging is active (%(hostname)s:%(port)s)"),
|
|
{'hostname': self.hosts.current.hostname,
|
|
'port': self.hosts.current.port})
|
|
self._schedule_task_processing()
|
|
|
|
# callback from eventloop on socket error
|
|
|
|
def socket_error(self, error):
|
|
"""Called by eventloop when a socket error occurs."""
|
|
LOG.error(_LE("Socket failure: %s"), error)
|
|
self._handle_connection_loss()
|
|
|
|
# Pyngus connection event callbacks (and their helpers), all invoked from
|
|
# the eventloop thread:
|
|
|
|
def connection_failed(self, connection, error):
|
|
"""This is a Pyngus callback, invoked by Pyngus when a non-recoverable
|
|
error occurs on the connection.
|
|
"""
|
|
if connection is not self._socket_connection.connection:
|
|
# pyngus bug: ignore failure callback on destroyed connections
|
|
return
|
|
LOG.debug("AMQP Connection failure: %s", error)
|
|
self._handle_connection_loss()
|
|
|
|
def connection_active(self, connection):
|
|
"""This is a Pyngus callback, invoked by Pyngus when the connection to
|
|
the peer is up. At this point, the driver will activate all subscriber
|
|
links (server) and the reply link.
|
|
"""
|
|
LOG.debug("Connection active (%(hostname)s:%(port)s), subscribing...",
|
|
{'hostname': self.hosts.current.hostname,
|
|
'port': self.hosts.current.port})
|
|
for servers in self._servers.values():
|
|
for server in servers.values():
|
|
server.attach(self._socket_connection.connection)
|
|
self._replies = Replies(self._socket_connection.connection,
|
|
lambda: self._reply_link_ready())
|
|
self._delay = 0
|
|
|
|
def connection_closed(self, connection):
|
|
"""This is a Pyngus callback, invoked by Pyngus when the connection has
|
|
cleanly closed. This occurs after the driver closes the connection
|
|
locally, and the peer has acknowledged the close. At this point, the
|
|
shutdown of the driver's connection is complete.
|
|
"""
|
|
LOG.debug("AMQP connection closed.")
|
|
# if the driver isn't being shutdown, failover and reconnect
|
|
self._handle_connection_loss()
|
|
|
|
def connection_remote_closed(self, connection, reason):
|
|
"""This is a Pyngus callback, invoked by Pyngus when the peer has
|
|
requested that the connection be closed.
|
|
"""
|
|
# The messaging service/broker is trying to shut down the
|
|
# connection. Acknowledge the close, and try to reconnect/failover
|
|
# later once the connection has closed (connection_closed is called).
|
|
if reason:
|
|
LOG.info(_LI("Connection closed by peer: %s"), reason)
|
|
self._socket_connection.connection.close()
|
|
|
|
def sasl_done(self, connection, pn_sasl, outcome):
|
|
"""This is a Pyngus callback invoked when the SASL handshake
|
|
has completed. The outcome of the handshake is passed in the outcome
|
|
argument.
|
|
"""
|
|
if outcome == proton.SASL.OK:
|
|
return
|
|
LOG.error(_LE("AUTHENTICATION FAILURE: Cannot connect to "
|
|
"%(hostname)s:%(port)s as user %(username)s"),
|
|
{'hostname': self.hosts.current.hostname,
|
|
'port': self.hosts.current.port,
|
|
'username': self.hosts.current.username})
|
|
# connection failure will be handled later
|
|
|
|
def _handle_connection_loss(self):
|
|
"""The connection to the messaging service has been lost. Try to
|
|
reestablish the connection/failover if not shutting down the driver.
|
|
"""
|
|
if self._closing:
|
|
# we're in the middle of shutting down the driver anyways,
|
|
# just consider it done:
|
|
self.processor.shutdown()
|
|
else:
|
|
# for some reason, we've lost the connection to the messaging
|
|
# service. Try to re-establish the connection:
|
|
if not self._reconnecting:
|
|
self._reconnecting = True
|
|
LOG.info(_LI("delaying reconnect attempt for %d seconds"),
|
|
self._delay)
|
|
self.processor.schedule(lambda: self._do_reconnect(),
|
|
self._delay)
|
|
self._delay = (1 if self._delay == 0
|
|
else min(self._delay * 2, 60))
|
|
|
|
def _do_reconnect(self):
|
|
"""Invoked on connection/socket failure, failover and re-connect to the
|
|
messaging service.
|
|
"""
|
|
if not self._closing:
|
|
self._hard_reset()
|
|
self._reconnecting = False
|
|
host = self.hosts.next()
|
|
LOG.info(_LI("Reconnecting to: %(hostname)s:%(port)s"),
|
|
{'hostname': host.hostname, 'port': host.port})
|
|
self._socket_connection.connect(host)
|
|
|
|
def _hard_reset(self):
|
|
"""Reset the controller to its pre-connection state"""
|
|
# note well: since this method destroys the connection, it cannot be
|
|
# invoked directly from a pyngus callback. Use processor.schedule() to
|
|
# run this method on the main loop instead.
|
|
for sender in self._senders.values():
|
|
sender.destroy()
|
|
self._senders.clear()
|
|
for servers in self._servers.values():
|
|
for server in servers.values():
|
|
# discard links, but keep servers around to re-attach if
|
|
# failing over
|
|
server.reset()
|
|
if self._replies:
|
|
self._replies.destroy()
|
|
self._replies = None
|
|
if self._socket_connection:
|
|
self._socket_connection.reset()
|