Python和RabbitMQ—侦听来自多个通道的消费事件的最佳方式?
我有两个单独的RabbitMQ实例。我正试图找到最好的方式来聆听双方的事件 例如,我可以使用具有以下内容的事件:Python和RabbitMQ—侦听来自多个通道的消费事件的最佳方式?,python,rabbitmq,pika,Python,Rabbitmq,Pika,我有两个单独的RabbitMQ实例。我正试图找到最好的方式来聆听双方的事件 例如,我可以使用具有以下内容的事件: credentials = pika.PlainCredentials(user, pass) connection = pika.BlockingConnection(pika.ConnectionParameters(host="host1", credentials=credentials)) channel = connection.channel() result = ch
credentials = pika.PlainCredentials(user, pass)
connection = pika.BlockingConnection(pika.ConnectionParameters(host="host1", credentials=credentials))
channel = connection.channel()
result = channel.queue_declare(Exclusive=True)
self.channel.queue_bind(exchange="my-exchange", result.method.queue, routing_key='*.*.*.*.*')
channel.basic_consume(callback_func, result.method.queue, no_ack=True)
self.channel.start_consuming()
我还有第二个主持人“host2”,我也想听听。我想创建两个独立的线程来实现这一点,但从我所读到的来看,pika不是线程安全的。有更好的办法吗?或者创建两个单独的线程,每个线程监听一个不同的兔子实例(host1和host2)就足够了吗?关于“最佳方式”的答案很大程度上取决于队列的使用模式以及“最佳”的含义。由于我还不能对问题发表评论,我将尝试提出一些可能的解决方案
在每个示例中,我将假设exchange已经声明
线程
您可以在单个进程中使用来自不同主机上的两个队列的消息
您是对的,pika
不是线程安全的,但它可以通过为每个线程创建到RabbitMQ主机的连接以多线程方式使用。使用模块在线程中运行此示例如下所示:
import pika
import threading
class ConsumerThread(threading.Thread):
def __init__(self, host, *args, **kwargs):
super(ConsumerThread, self).__init__(*args, **kwargs)
self._host = host
# Not necessarily a method.
def callback_func(self, channel, method, properties, body):
print("{} received '{}'".format(self.name, body))
def run(self):
credentials = pika.PlainCredentials("guest", "guest")
connection = pika.BlockingConnection(
pika.ConnectionParameters(host=self._host,
credentials=credentials))
channel = connection.channel()
result = channel.queue_declare(exclusive=True)
channel.queue_bind(result.method.queue,
exchange="my-exchange",
routing_key="*.*.*.*.*")
channel.basic_consume(self.callback_func,
result.method.queue,
no_ack=True)
channel.start_consuming()
if __name__ == "__main__":
threads = [ConsumerThread("host1"), ConsumerThread("host2")]
for thread in threads:
thread.start()
我已经声明了callback\u func
作为一种方法,在打印消息正文时纯粹使用ConsumerThread.name
。它也可能是ConsumerThread
类之外的函数
过程
或者,对于要使用事件的每个队列,始终可以使用使用者代码运行一个进程
import pika
import sys
def callback_func(channel, method, properties, body):
print(body)
if __name__ == "__main__":
credentials = pika.PlainCredentials("guest", "guest")
connection = pika.BlockingConnection(
pika.ConnectionParameters(host=sys.argv[1],
credentials=credentials))
channel = connection.channel()
result = channel.queue_declare(exclusive=True)
channel.queue_bind(result.method.queue,
exchange="my-exchange",
routing_key="*.*.*.*.*")
channel.basic_consume(callback_func, result.method.queue, no_ack=True)
channel.start_consuming()
然后由以下人员运行:
$ python single_consume.py host1
$ python single_consume.py host2 # e.g. on another console
如果您对来自队列的消息所做的工作是,并且只要CPU中的内核数>=使用者数,通常最好使用这种方法-除非您的队列大部分时间是空的,并且使用者不会利用此CPU时间*
异步的
另一种选择是涉及一些异步框架(例如),并在单个线程中运行整个过程
您不能再在异步代码中使用BlockingConnection
;幸运的是,pika
有用于Twisted
的适配器:
from pika.adapters.twisted_connection import TwistedProtocolConnection
from pika.connection import ConnectionParameters
from twisted.internet import protocol, reactor, task
from twisted.python import log
class Consumer(object):
def on_connected(self, connection):
d = connection.channel()
d.addCallback(self.got_channel)
d.addCallback(self.queue_declared)
d.addCallback(self.queue_bound)
d.addCallback(self.handle_deliveries)
d.addErrback(log.err)
def got_channel(self, channel):
self.channel = channel
return self.channel.queue_declare(exclusive=True)
def queue_declared(self, queue):
self._queue_name = queue.method.queue
self.channel.queue_bind(queue=self._queue_name,
exchange="my-exchange",
routing_key="*.*.*.*.*")
def queue_bound(self, ignored):
return self.channel.basic_consume(queue=self._queue_name)
def handle_deliveries(self, queue_and_consumer_tag):
queue, consumer_tag = queue_and_consumer_tag
self.looping_call = task.LoopingCall(self.consume_from_queue, queue)
return self.looping_call.start(0)
def consume_from_queue(self, queue):
d = queue.get()
return d.addCallback(lambda result: self.handle_payload(*result))
def handle_payload(self, channel, method, properties, body):
print(body)
if __name__ == "__main__":
consumer1 = Consumer()
consumer2 = Consumer()
parameters = ConnectionParameters()
cc = protocol.ClientCreator(reactor,
TwistedProtocolConnection,
parameters)
d1 = cc.connectTCP("host1", 5672)
d1.addCallback(lambda protocol: protocol.ready)
d1.addCallback(consumer1.on_connected)
d1.addErrback(log.err)
d2 = cc.connectTCP("host2", 5672)
d2.addCallback(lambda protocol: protocol.ready)
d2.addCallback(consumer2.on_connected)
d2.addErrback(log.err)
reactor.run()
这种方法会更好,您从中消耗的队列越多,消费者执行的工作受到的CPU限制就越少*
Python 3
由于您提到了pika
,我将自己局限于基于python2.x的解决方案,因为pika
尚未移植
但是,如果您想转到>=3.3,一个可能的选项是与AMQP协议(您与RabbitMQ交谈的协议)之一一起使用,例如,或
*-请注意,这些都是非常肤浅的提示-在大多数情况下,选择不是那么明显;什么对您最有利取决于队列“饱和”(消息/时间)、您在收到这些消息时做什么工作、您在什么环境中运行您的消费者等。;除了对所有实现进行基准测试之外,没有其他方法可以确定下面是我如何使用一个rabbitmq实例同时侦听两个队列的示例:
import pika
import threading
threads=[]
def client_info(channel):
channel.queue_declare(queue='proxy-python')
print (' [*] Waiting for client messages. To exit press CTRL+C')
def callback(ch, method, properties, body):
print (" Received %s" % (body))
channel.basic_consume(callback, queue='proxy-python', no_ack=True)
channel.start_consuming()
def scenario_info(channel):
channel.queue_declare(queue='savi-virnet-python')
print (' [*] Waiting for scenrio messages. To exit press CTRL+C')
def callback(ch, method, properties, body):
print (" Received %s" % (body))
channel.basic_consume(callback, queue='savi-virnet-python', no_ack=True)
channel.start_consuming()
def manager():
connection1= pika.BlockingConnection(pika.ConnectionParameters
(host='localhost'))
channel1 = connection1.channel()
connection2= pika.BlockingConnection(pika.ConnectionParameters
(host='localhost'))
channel2 = connection2.channel()
t1 = threading.Thread(target=client_info, args=(channel1,))
t1.daemon = True
threads.append(t1)
t1.start()
t2 = threading.Thread(target=scenario_info, args=(channel2,))
t2.daemon = True
threads.append(t2)
t2.start()
for t in threads:
t.join()
manager()
您可以异步使用aio pika
这里有更多的例子
快乐编码:)Hi@Unit03我知道你在2015年已经回答了。我使用的是同一个扭曲的适配器,我丢失了太多的心跳。您可以访问我的问题以获取代码和更多说明。嗨,瓦伊巴夫,我已经回答了这个问题。
import asyncio
import tornado.ioloop
import tornado.web
from aio_pika import connect_robust, Message
tornado.ioloop.IOLoop.configure("tornado.platform.asyncio.AsyncIOLoop")
io_loop = tornado.ioloop.IOLoop.current()
asyncio.set_event_loop(io_loop.asyncio_loop)
QUEUE = asyncio.Queue()
class SubscriberHandler(tornado.web.RequestHandler):
async def get(self):
message = await QUEUE.get()
self.finish(message.body)
class PublisherHandler(tornado.web.RequestHandler):
async def post(self):
connection = self.application.settings["amqp_connection"]
channel = await connection.channel()
try:
await channel.default_exchange.publish(
Message(body=self.request.body), routing_key="test",
)
finally:
await channel.close()
print('ok')
self.finish("OK")
async def make_app():
amqp_connection = await connect_robust()
channel = await amqp_connection.channel()
queue = await channel.declare_queue("test", auto_delete=True)
await queue.consume(QUEUE.put, no_ack=True)
return tornado.web.Application(
[(r"/publish", PublisherHandler), (r"/subscribe", SubscriberHandler)],
amqp_connection=amqp_connection,
)
if __name__ == "__main__":
app = io_loop.asyncio_loop.run_until_complete(make_app())
app.listen(8888)
tornado.ioloop.IOLoop.current().start()