python - RabbitMQ pika.exceptions.ConnectionClosed

Question

我尝试使用 RabbitMQ 发送消息和接收消息。我没有计算机科学背景，我使用的术语可能不是很准确。

我尝试复制教程文件:提交我的 html 表单时，我的 python 脚本 (cgi) 将消息提交到队列

connection = pika.BlockingConnection(pika.ConnectionParameters(host='localhost'))
        channel = connection.channel()
        channel.queue_declare(queue='task_queue', durable=True)
        message = PN
        channel.basic_publish(exchange='',
                              routing_key='task_queue',
                              body=message,
                              properties=pika.BasicProperties(
                                 delivery_mode = 2, # make message persistent
                              ))
        connection.close()

我的接收器正在运行:

connection = pika.BlockingConnection(pika.ConnectionParameters(host='localhost'))
channel = connection.channel()
channel.queue_declare(queue='task_queue', durable=True)
print(' [*] Waiting for messages. To exit press CTRL+C')

def callback(ch, method, properties, body):
    print(" [x] Received Project %r" % body)
    #ch.basic_ack(delivery_tag = method.delivery_tag) 
    if not (os.path.isfile(js_path)):
        print (' [*] ERROR files missing ')
        #ch.basic_ack(delivery_tag = method.delivery_tag)
        return
    p= subprocess.Popen(run a subprocess here)
    p.wait()

    print (' [*] Temporary Files removed')
    print(" [*] Waiting for messages. To exit press CTRL+C")

channel.basic_qos(prefetch_count=1)
channel.basic_consume(callback,queue='task_queue',no_ack=True)
channel.start_consuming()

它管理大部分时间，但随机崩溃并出现以下错误:

Traceback (most recent call last): File "Receive5.py", line 139, in channel.start_consuming() File "C:\Python27\lib\site-packages\pika\adapters\blocking_connection.py", line 1681, in start_consuming self.connection.process_data_events(time_limit=None) File "C:\Python27\lib\site-packages\pika\adapters\blocking_connection.py", line 647, in process_data_events self._flush_output(common_terminator) File "C:\Python27\lib\site-packages\pika\adapters\blocking_connection.py", line 426, in _flush_output raise exceptions.ConnectionClosed() pika.exceptions.ConnectionClosed

Answer 1

这是因为你让主线程一直在等待，因此 pika 无法处理传入的消息；在这种情况下，在子进程完成之前它无法响应心跳。这导致 RabbitMQ 认为客户端已死并强制断开连接。

如果您希望它与心跳一起工作(推荐)，您需要定期调用 connection.process_data_events。这可以通过添加一个循环来检查线程是否完成，并且每 30 秒左右调用一次 process_data_events 直到线程完成。