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一,RabbitMQ简单介绍:
RabbitMQ是一个在AMQP基础上完整的,可复用的企业消息系统。他遵循Mozilla Public License开源协议。
MQ全称为Message Queue, (MQ)是一种应用程序对应用程序的通信方法。应用程序通过读写出入队列的消息(针对应用程序的数据)来通信,而无需专用连接来链接它们。消 息传递指的是程序之间通过在消息中发送数据进行通信,而不是通过直接调用彼此来通信,直接调用通常是用于诸如的技术。排队指的是应用程序通过 队列来通信。队列的使用除去了接收和发送应用程序同时执行的要求。
二,安装
pip install pika
三,简单队列
1丶使用API操作RabbitMQ
基于Queue实现生产者消费者模型
1234567891011121314151617181920212223242526#!/usr/bin/env python# -*- coding:utf-8 -*-import Queueimport threading message = Queue.Queue(10) def producer(i): while True: message.put(i) def consumer(i): while True: msg = message.get() for i in range(12): t = threading.Thread(target=producer, args=(i,)) t.start() for i in range(10): t = threading.Thread(target=consumer, args=(i,)) t.start()
对于RabbitMQ来说,生产和消费不再针对内存里的一个Queue对象,而是某台服务器上的RabbitMQ Server实现的消息队列。
# !/usr/bin/env python# -*- coding:utf-8 -*- import pika connection = pika.BaseConnection(pika.ConnectionParameters(host='10.211.55.4')) # 封装socket逻辑部分channel = connection.channel() # 拿到操作句柄 channel.queue_declare(queue='hello') # 通过channel创建一个队列,再给给队列取名字 channel.basic_publish(exchange='', # 通过句柄给 routing_key='hello', # 把body的数据放到名为hello的队列里去 body='Hello World!', ))print("[x] Sent 'Hello World!")connection.close()
# !/usr/bin/env python# -*- coding:utf-8 -*- import pika connection = pika.BaseConnection(pika.ConnectionParameters(host='10.211.55.4'))channel = connection.channel() channel.queue_declare(queue='hello') # 创建队列 def callback(ch, method, properties, body): # 就是个回调函数 print(" [x] Received %r" % body) channel.basic_consume(callback, # 函数名;取出数据就执行这个函数 queue='hello', # 队列名 no_ack=Ture) # 无应答是(Ture);有应答(False) print(' [*] Waiting for messages.To exit press CTRL+C')channel.start_consuming()
2丶acknowledgment消息不丢失
no-ack = False,如果消费者遇到情况(its channel is closed, connection is closed, or TCP connection is lost)挂掉了,那么,RabbitMQ会重新将该任务添加到队列中。
# !/usr/bin/env python# -*- coding:utf-8 -*-import pikaconnection = pika.BaseConnection(pika.ConnectionParameters(host='10.211.55.4'))channel = connection.channel()channel.queue_declare(queue='hello') # 创建队列def callback(ch, method, properties, body): # 就是个回调函数 print(" [x] Received %r" % body) import time time.sleep(10) print('ok') ch.basic_ack(delivery_tag=method.delivery_tag) # 调为有应答要加上的(下面的要改no_ack=False)channel.basic_qos(prefetch_count=1)channel.basic_consume(callback, # 函数名;取出数据就执行这个函数 queue='hello', # 队列名 no_ack=False) # 无应答是(Ture);有应答(False)print(' [*] Waiting for messages.To exit press CTRL+C')channel.start_consuming()
3丶durable消息不丢失
import pika connection = pika.BlockingConnection(pika.ConnectionParameters(host='10.211.55.4'))channel = connection.channel() # make message persistentchannel.queue_declare(queue='hello', durable=True) # durable=True这个参数是把数据保存到硬盘 channel.basic_publish(exchange='', routing_key='hello', body='Hello World!', properties=pika.BasicProperties( delivery_mode=2, # 传递模式从默认的1,改为2 ))print(" [x] Sent 'Hello World!'")connection.close()
#!/usr/bin/env python# -*- coding:utf-8 -*-import pika connection = pika.BlockingConnection(pika.ConnectionParameters(host='10.211.55.4'))channel = connection.channel() # make message persistentchannel.queue_declare(queue='hello', durable=True) def callback(ch, method, properties, body): print(" [x] Received %r" % body) import time time.sleep(10) print 'ok' ch.basic_ack(delivery_tag = method.delivery_tag) # 把无应答调整为有应答 channel.basic_consume(callback, queue='hello', no_ack=False) # 改为False,表示有应答 print(' [*] Waiting for messages. To exit press CTRL+C')channel.start_consuming()
4丶消息获取顺序
默认消息队列里的数据是按照顺序被消费者拿走,例如:消费者1 去队列中获取 奇数 序列的任务,消费者1去队列中获取 偶数 序列的任务。
channel.basic_qos(prefetch_count=1) 表示谁来谁取,不再按照奇偶数排列
#!/usr/bin/env python# -*- coding:utf-8 -*-import pikaconnection = pika.BlockingConnection(pika.ConnectionParameters(host='10.211.55.4'))channel = connection.channel()# make message persistentchannel.queue_declare(queue='hello')def callback(ch, method, properties, body): print(" [x] Received %r" % body) import time time.sleep(10) print 'ok' ch.basic_ack(delivery_tag = method.delivery_tag)channel.basic_qos(prefetch_count=1) # prefetch_count=1这个参数就让取的方式改变,不在顺序取数据channel.basic_consume(callback, queue='hello', no_ack=False)print(' [*] Waiting for messages. To exit press CTRL+C')channel.start_consuming()
四,exchange
发布订阅和简单的消息队列区别在于,发布订阅会将消息发送给所有的订阅者,而消息队列中的数据被消费一次便消失。
所以,RabbitMQ实现发布和订阅时,会为每一个订阅者创建一个队列,而发布者发布消息时,会将消息放置在所有相关队列中。
exchange type = fanout
#!/usr/bin/env pythonimport pikaimport sys connection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost'))channel = connection.channel() # 创建交换机channel.exchange_declare(exchange='logs', # 名字 type='fanout') # 类型 message = ' '.join(sys.argv[1:]) or "info: Hello World!"channel.basic_publish(exchange='logs', # 往名字为logs的交换机里 routing_key='', # 把数据直接放到交换机里,不用放到队列中,所以默认为空 body=message)print(" [x] Sent %r" % message)connection.close() # 关闭
#!/usr/bin/env pythonimport pika connection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost'))channel = connection.channel() #创建交换机channel.exchange_declare(exchange='logs', type='fanout') # 随机创建一个队列result = channel.queue_declare(exclusive=True)queue_name = result.method.queue channel.queue_bind(exchange='logs', # 随机生成的队列绑定交换机 queue=queue_name) print(' [*] Waiting for logs. To exit press CTRL+C') def callback(ch, method, properties, body): print(" [x] %r" % body) channel.basic_consume(callback, # 在下面阻塞后,如果得到数据后才执行这个函数 queue=queue_name, no_ack=True) channel.start_consuming() # 阻塞住,等待生产者把数据放到消费者,并监听
图形解释:
RabbitMQ 还支持根据关键字发送,即:队列绑定关键字,发送者将数据根据关键字发送到消息exchange,
exchange 根据 关键字 判定应该将数据发送至指定队列。
exchange type = direct
#!/usr/bin/env pythonimport pikaimport sysconnection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost'))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 'Hello World!'channel.basic_publish(exchange='direct_logs', routing_key=severity, body=message)print(" [x] Sent %r:%r" % (severity, message))connection.close()
#!/usr/bin/env pythonimport pikaimport sysconnection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost'))channel = connection.channel()channel.exchange_declare(exchange='direct_logs', type='direct')result = channel.queue_declare(exclusive=True)queue_name = result.method.queueseverities = 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: # 用循环是可以绑定多个队列 channel.queue_bind(exchange='direct_logs', queue=queue_name, routing_key='severity') # 定义的参数(关键字) channel.queue_bind(exchange='direct_logs', queue=queue_name, routing_key='alex')print(' [*] Waiting for logs. To exit press CTRL+C')def callback(ch, method, properties, body): print(" [x] %r:%r" % (method.routing_key, body))channel.basic_consume(callback, queue=queue_name, no_ack=True)channel.start_consuming()
图形解释:
在交换机中用一关键字,只有队列里有关键字交换机才会发送数据给绑定的队列。
模糊匹配
在topic类型下,可以让队列绑定几个模糊的关键字,之后发送者将数据发送到exchange,exchange将传入”路由值“和 ”关键字“进行匹配,
匹配成功,则将数据发送到指定队列。exchange type = topic
# 表示可以匹配 0 个 或 多个 单词* 表示只能匹配 一个 单词 发送者路由值 队列中old.boy.python old.* -- 不匹配old.boy.python old.# -- 匹配
#!/usr/bin/env pythonimport pikaimport sysconnection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost'))channel = connection.channel()channel.exchange_declare(exchange='topic_logs', type='topic')routing_key = sys.argv[1] if len(sys.argv) > 1 else 'anonymous.info'message = ' '.join(sys.argv[2:]) or 'Hello World!'channel.basic_publish(exchange='topic_logs', routing_key=routing_key, body=message)print(" [x] Sent %r:%r" % (routing_key, message))connection.close()
#!/usr/bin/env pythonimport pikaimport sysconnection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost'))channel = connection.channel()channel.exchange_declare(exchange='topic_logs', type='topic')result = channel.queue_declare(exclusive=True)queue_name = result.method.queuebinding_keys = sys.argv[1:]if not binding_keys: sys.stderr.write("Usage: %s [binding_key]...\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)print(' [*] Waiting for logs. To exit press CTRL+C')def callback(ch, method, properties, body): print(" [x] %r:%r" % (method.routing_key, body))channel.basic_consume(callback, queue=queue_name, no_ack=True)channel.start_consuming()
图形解释:
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