Python RabbitMQ实现简单的进程间通信示例

时间：2020-09-02 python教程查看: 838

RabbitMQ 消息队列

PY
threading Queue
进程Queue 父进程与子进程，或同一父进程下的多个子进程进行交互
缺点：两个不同Python文件不能通过上面两个Queue进行交互

erlong
基于这个语言创建的一种中间商
win中需要先安装erlong才能使用
rabbitmq_server start

安装 Python module

pip install pika

easy_install pika

or
源码

rabbit 默认端口15672
查看当前时刻的队列数
rabbitmqctl.bat list_queue

exchange
在定义的时候就是有类型的，决定到底哪些queue符合条件，可以接受消息
fanout：所有bind到此exchange的queue都可以收到消息
direct：通过routingkey和exchange决定唯一的queue可以接受消息
topic：所有符合routingkey（此时可以是一个表达式）的routingkey所bind的queue都可以接受消息
表达式符号说明：
# 代表一个或多个字符 * 代表任何字符

RPC
remote procedure call 双向传输，指令<-------->指令执行结果
实现方法：创建两个队列，一个队列收指令，一个队列发送执行结果

用rabbitmq实现简单的生产者消费者模型

1） rabbit_producer.py

# Author : Xuefeng

import pika

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()

# create the queue, the name of queue is "hello"
# durable=True can make the queue be exist, although the service have stopped before.
channel.queue_declare(queue="hello", durable=True)

# n RabbitMQ a message can never be sent directly to queue,it always need to go through
channel.basic_publish(exchange = " ",
      routing_key = "hello",
      body = "Hello world!",
      properties = pika.BasicPropreties(
       delivery_mode=2, # make the message persistence
      )
      )
print("[x] sent 'Hello world!'")
connection.close()

2） rabbit_consumer.py

# Author : Xuefeng

import pika

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()
channel.queue_declare(queue="hello", durable=True)

def callback(ch, method, properties, body):
 '''
 Handle the recieved data
 :param ch: The address of the channel
 :param method: Information about the connection
 :param properties:
 :param body:
 :return:
 '''
 print("------>", ch, method, properties )
 print("[x] Recieved %r" % body)
 # ack by ourself
 ch.basic_ack(delivery_tag = method.delivery_tag)

# follow is for consumer to auto change with the ability
channel.basic_qos(profetch_count=1)
# no_ack = True represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback,  # If have recieved message, enable the callback() function to handle the message.
      queue = "hello",
      no_ack = True)

print("[*] Waiting for messages. To Exit press CTRL+C")
channel.start_consuming()

用rabbitmq中的fanout模式实现广播模式

1） fanout_rabbit_publish.py

# Author : Xuefeng

import pika
import sys

# 广播模式：
# 生产者发送一条消息，所有的开通链接的消费者都可以接收到消息

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()
channel.exchange_declare(exchange="logs",
       type="fanout")
message = ' '.join(sys.argv[1:]) or "info:Hello world!"
channel.basic_publish(
 exchange="logs",
 routing_key="",
 body=message
)
print("[x] Send %r" % message)

connection.close()

2） fanout_rabbit_consumer.py

# Author : Xuefeng


import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()
# exclusive 排他，唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

channel.queue_bind(exchange="logs",
     queue=queue_name)


def callback(ch, method, properties, body):
 '''
 Handle the recieved data
 :param ch: The address of the channel
 :param method: Information about the connection
 :param properties:
 :param body:
 :return:
 '''
 print("------>", ch, method, properties )
 print("[x] Recieved %r" % body)
 # ack by ourself
 ch.basic_ack(delivery_tag = method.delivery_tag)

# no_ack = True represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback,  # If have recieved message, enable the callback() function to handle the message.
      queue = "hello",
      no_ack = True)

print("[*] Waiting for messages. To Exit press CTRL+C")
channel.start_consuming()

用rabbitmq中的direct模式实现消息过滤模式

1） direct_rabbit_publisher.py

# Author : Xuefeng
import pika
import sys

# 消息过滤模式：
# 生产者发送一条消息，通过severity优先级来确定是否可以接收到消息

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()
channel.exchange_declare(exchange="direct_logs",
       type="direct")
severity = sys.argv[1] if len(sys.argv) > 1 else "info"
message = ' '.join(sys.argv[2:]) or "info:Hello world!"

channel.basic_publish(
 exchange="direct_logs",
 routing_key=severity,
 body=message
)
print("[x] Send %r:%r" % (severity, message))

connection.close()

2） direct_rabbit_consumer.py

# Author : Xuefeng

import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()

channel.exchange_declare(exchange="direct_logs",
       type="direct")

# exclusive 排他，唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

severities = sys.argv[1:]
if not severities:
 sys.stderr.write("Usage:%s [info] [warning] [error]\n" % sys.argv[0])
 sys.exit(1)

for severity in severities:
 channel.queue_bind(exchange="direct_logs",
      queue=queue_name,
      routing_key=severity)



def callback(ch, method, properties, body):
 '''
 Handle the recieved data
 :param ch: The address of the channel
 :param method: Information about the connection
 :param properties:
 :param body:
 :return:
 '''
 print("------>", ch, method, properties )
 print("[x] Recieved %r" % body)
 # ack by ourself
 ch.basic_ack(delivery_tag = method.delivery_tag)

# no_ack = True represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback,  # If have recieved message, enable the callback() function to handle the message.
      queue = "hello",
      no_ack = True)

print("[*] Waiting for messages. To Exit press CTRL+C")
channel.start_consuming()

用rabbitmq中的topic模式实现细致消息过滤模式

1） topic_rabbit_publisher.py

# Author : Xuefeng

import pika
import sys

# 消息细致过滤模式：
# 生产者发送一条消息，通过运行脚本 *.info 等确定接收消息类型进行对应接收
connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()
channel.exchange_declare(exchange="topic_logs",
       type="topic")
binding_key = sys.argv[1] if len(sys.argv) > 1 else "info"
message = ' '.join(sys.argv[2:]) or "info:Hello world!"

channel.basic_publish(
 exchange="topic_logs",
 routing_key=binding_key,
 body=message
)
print("[x] Send %r:%r" % (binding_key, message))

connection.close()

2） topic_rabbit_consumer.py

# Author : Xuefeng

import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()

channel.exchange_declare(exchange="topic_logs",
       type="topic")

# exclusive 排他，唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

binding_keys = sys.argv[1:]
if not binding_keys:
 sys.stderr.write("Usage:%s [info] [warning] [error]\n" % sys.argv[0])
 sys.exit(1)

for binding_key in binding_keys:
 channel.queue_bind(exchange="topic_logs",
      queue=queue_name,
      routing_key=binding_key)


def callback(ch, method, properties, body):
 '''
 Handle the recieved data
 :param ch: The address of the channel
 :param method: Information about the connection
 :param properties:
 :param body:
 :return:
 '''
 print("------>", ch, method, properties)
 print("[x] Recieved %r" % body)
 # ack by ourself
 ch.basic_ack(delivery_tag=method.delivery_tag)


# no_ack = True represent that the message cannot be transfor to next consumer,
# when the current consumer is stop by accident.
channel.basic_consume(callback, # If have recieved message, enable the callback() function to handle the message.
      queue="hello",
      no_ack=True)

print("[*] Waiting for messages. To Exit press CTRL+C")
channel.start_consuming()

用rabbitmq实现rpc操作

1） Rpc_rabbit_client.py

# Author : Xuefeng

import pika
import time
import uuid

class FibonacciRpcClient(object):
 def __init__(self):
  self.connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"))
  self.channel = self.connection.channel()
  result = self.channel.queue_declare(exclusive=True)
  self.callback_queue = result.method.queue  # 随机的生成一个接收命令执行结果的队列
  self.channel.basic_consume(self.on_response, # 只要收到消息就调用
         no_ack=True,
         queue=self.callback_queue)

 def on_response(self, ch, method, props, body):
  if self.corr_id == props.correlation_id:
   self.response = body

 def call(self,n):
  self.response = None
  self.corr_id = str(uuid.uuid4())
  self.channel.basic_publish(
   exchange="",
   routing_key="rpc_queue",
   properties=pika.BasicPropreties(
    rely_to=self.callback_queue,
    correlation_id=self.corr_id   # 通过随机生成的ID来验证指令执行结果与指令的匹配性
   ),
   body=str(n)
  )
  while self.response is None:
   self.connection.process_data_events() # 非阻塞版的start_consume，有没有消息都继续
   print("no message...")
   time.sleep(0.5)
  return int(self.response)

fibonacci_rcp = FibonacciRpcClient()

print("[x] Requesting fib(30)")
response = fibonacci_rcp.call(30)
print("[x] Rec %r" % response)

2） Rpc_rabbit_server.py

# Author : Xuefeng

import pika
import sys

connection = pika.BlockingConnection(pika.Connection.Parameters(
 "localhost"
))
# statement a channel
channel = connection.channel()

channel.queue_declare(queue="rpc_queue")

def fib(n):
 if n == 0:
  return 0
 elif n == 1:
  return 1
 else:
  return fib(n-1)+fib(n-2)

def on_request(ch, method, props, body):
 n = int(body)
 print("[.] fib(%s)" % n)
 response = fib(n)
 ch.basic_publish(
  exchange="",
  routing_key=props.rely_to,
  properties=pika.BasicPropreties(correlation_id=\
          props.correlation),
  body = str(body)
 )
 ch.basic_ack(delivery_tag=method.delivery_tag)

channel.basic_qos(prefetch_count=1)
channel.basic_consume(on_request, queue="rpc_queue")

print("[x] Awaiting RPC requests")
channel.start_consumeing()



channel.exchange_declare(exchange="direct_logs",
       type="direct")

# exclusive 排他，唯一的 随机生成queue
result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue
print("Random queue name:", queue_name)

severities = sys.argv[1:]

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