Question

我正在尝试使用async/await从Azure ServiceBus主题读取消息，然后通过HTTP将内容转发到另一个应用程序。我的代码很简单：

import asyncio
from aiohttp import ClientSession
from azure.servicebus.aio.async_client import ServiceBusService

bus_service = ServiceBusService(service_namespace=..., shared_access_key_name=..., shared_access_key_value=...)

async def watch(topic_name, subscription_name):
    print('{} started'.format(topic_name))

    message = bus_service.receive_subscription_message(topic_name, subscription_name, peek_lock=False, timeout=1)

    if message.body is not None:
        async with ClientSession() as session:
            await session.post('ip:port/endpoint',
                               headers={'Content-type': 'application/x-www-form-urlencoded'},
                               data={'data': message.body.decode()})


async def do():
    while True:
        for topic in ['topic1', 'topic2', 'topic3']:
            await watch(topic, 'watcher')


if __name__ == "__main__":
    asyncio.run(do())

我想从各种主题中寻找消息（永远），当消息到达时发送POST。我从aio导入了azure软件包，该软件包应该以异步方式工作。经过多次尝试，我得到的唯一解决方案是使用while True并设置timeout=1。这不是我想要的，我按顺序进行。

azure-servicebus版本0.50.3。

这是我第一次与async/await在一起，可能是我遗漏了一些东西...
有解决方案/建议吗？

Answer 1

以下是使用 servicebus 的最新主要版本 v7 的方法请查看异步示例以发送和接收订阅消息 https://github.com/Azure/azure-sdk-for-python/blob/04290863fa8963ec525a0b2f4079595287e15d93/sdk/servicebus/azure-servicebus/samples/async_samples/sample_code_servicebus_async.py

import os
import asyncio
from aiohttp import ClientSession
from azure.servicebus.aio import ServiceBusClient
connstr = os.environ['SERVICE_BUS_CONNECTION_STR']
topic_name = os.environ['SERVICE_BUS_TOPIC_NAME']
subscription_name = os.environ['SERVICE_BUS_SUBSCRIPTION_NAME']

async def watch(topic_name, subscription_name):
    async with ServiceBusClient.from_connection_string(conn_str=servicebus_connection_str) as servicebus_client:
        subscription_receiver = servicebus_client.get_subscription_receiver(
            topic_name=topic_name,
            subscription_name=subscription_name,
        )
    async with subscription_receiver:
         message = await subscription_receiver.receive_messages(max_wait_time=1)

    if message.body is not None:
        async with ClientSession() as session:
            await session.post('ip:port/endpoint',
                               headers={'Content-type': 'application/x-www-form-urlencoded'},
                               data={'data': message.body.decode()})

async def do():
    while True:
        for topic in ['topic1', 'topic2', 'topic3']:
            await watch(topic, 'watcher')


if __name__ == "__main__":
    loop = asyncio.get_event_loop()
    loop.run_until_complete(do())

Answer 2

您将必须使用软件包：azure.servicebus.aio

它们具有以下用于异步的模块：

我们将不得不使用Receive处理程序类-它可以使用get_receiver（）方法实例化。有了这个对象，您将能够异步地遍历消息。整理一个示例脚本，这样做可以进一步优化它：

from azure.servicebus.aio import SubscriptionClient
import asyncio
import nest_asyncio
nest_asyncio.apply()

        
Receiving = True

#Topic 1 receiver : 
conn_str= "<>"
name="Allmessages1"
SubsClient = SubscriptionClient.from_connection_string(conn_str, name)
receiver =  SubsClient.get_receiver()

#Topic 2 receiver : 
conn_str2= "<>"
name2="Allmessages2"
SubsClient2 = SubscriptionClient.from_connection_string(conn_str2, name2)
receiver2 =  SubsClient2.get_receiver()
    
#obj= SubscriptionClient("svijayservicebus","mytopic1", shared_access_key_name="RootManageSharedAccessKey", shared_access_key_value="ySr+maBCmIRDK4I1aGgkoBl5sNNxJt4HTwINo0FQ/tc=")
async def receive_message_from1():
    await receiver.open()
    print("Opening the Receiver for Topic1")
    async with receiver:
      while(Receiving):
        msgs =  await receiver.fetch_next()
        for m in msgs:
            print("Received the message from topic 1.....")
            print(str(m))
            await m.complete()
       
async def receive_message_from2():
    await receiver2.open()
    print("Opening the Receiver for Topic2")
    async with receiver2:
      while(Receiving):
        msgs =  await receiver2.fetch_next()
        for m in msgs:
            print("Received the message from topic 2.....")
            print(str(m))
            await m.complete()
               



loop = asyncio.get_event_loop()
topic1receiver = loop.create_task(receive_message_from1())
topic2receiver = loop.create_task(receive_message_from2())

我创建了两个任务来促进并发。您可以参考this帖子以使它们更加清晰。

输出：

在Python中使用异步/等待的Azure ServiceBus似乎不起作用

2 个答案: