Python-Day11 RabbitMQ/redis

写在前面：

好久不写了，实在是不想写，坚持果然是一件不容易的事情。

我喜欢玩，我更爱学习，然而喜欢是放肆，爱是克制，哈哈。每天上班有些忙就不想动，只想在床上翻滚或者鏖战召唤师峡谷。上班闲着时想了想，一是不方便写，二是忘了很多了---------经过铺垫可以明确的说了：前面都是借口。

白天自己承诺自己晚上要写，虽然没人知道，自己答应自己的事也不能不做啊，晚上复习了一个多小时，现在是实践的时候了：Come on baby,不逼自己一把，你永远不知道自己有多优秀。So anyway,鸡汤香否，哈哈哈，就喜欢转折转的措手不及，这是一种乐观的生活态度。历千劫万险，纵使魂飞魄散，我灵识依在，战百世轮回，纵使六道无常，我依然相信你可以在下面点个赞。

一、RabbitMQ队列

1.RabbitMQ介绍

MQ全称为Message Queue, 消息队列（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。

MQ是消费-生产者模型的一个典型的代表，一端往消息队列中不断写入消息，而另一端则可以读取或者订阅队列中的消息。

Python-Day11 RabbitMQ/redis

2.RabbitMQ安装（Windows）

http://www.rabbitmq.com/install-windows.html

安装python rabbitMQ module

#windows在cmd里执行即可
#（如果不能找不到命令是Python没有设置好环境变量，手动找pip命令）
pip install pika
or
easy_install pika
or
源码
https://pypi.python.org/pypi/pika

3.实现最简单的队列通信

send端

import pika
connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
#声明queue
channel.queue_declare(queue='hello')
#n RabbitMQ a message can never be sent directly to the queue, it always needs to go through an exchange.
channel.basic_publish(exchange='',
                      routing_key='hello', #routing_key 就是queue名
                      body='Hello World!',
                     )
print(" [x] Sent 'Hello World!'")
connection.close()

receive端

import pika
connection = pika.BlockingConnection(pika.ConnectionParameters(
               'localhost'))
channel = connection.channel()
#You may ask why we declare the queue again ‒ we have already declared it in our previous code.
#We could avoid that if we were sure that the queue already exists. For example if send.py program
#was run before. But we're not yet sure which program to run first. In such cases it's a good
#practice to repeat declaring the queue in both programs.
channel.queue_declare(queue='hello')
def callback(ch, method, properties, body):
    print(ch,method,properties)
#ch <pika.adapters.blocking_connection.BlockingChannel object at 0x00000000029A5C50> 管理内存对象地址
#method <Basic.Deliver(['consumer_tag=ctag1.aef832e45baf4745af94ab1b2b75ff22', 'delivery_tag=1', 'exchange=', 'redelivered=False', 'routing_key=hello'])> 具体信息
#properties:<BasicProperties>

    print(" --> Received %r" % body)
    ch.basic_ack(delivery_tag=method.delivery_tag)
channel.basic_qos(prefetch_count=1)
channel.basic_consume(callback,
                      queue='hello'
                      no_ack=True)
print(' [*] Waiting for messages. To exit press CTRL+C')
channel.start_consuming()

4.RabbitMQ消息分发轮询

在这种模式下，RabbitMQ会默认把p发的消息依次分发给各个消费者(c),跟负载均衡差不多

import pika
 
connection = pika.BlockingConnection(pika.ConnectionParameters(
               'localhost'))
channel = connection.channel()
 
#声明queue
channel.queue_declare(queue='task_queue')
 
#n RabbitMQ a message can never be sent directly to the queue, it always needs to go through an exchange.
import sys
 
message = ' '.join(sys.argv[1:]) or "Hello World!"
channel.basic_publish(exchange='',
                      routing_key='task_queue',
                      body=message,
                      properties=pika.BasicProperties(
                      delivery_mode = 2, # make message persistent
                      ))
print(" [x] Sent %r" % message)
connection.close()

发送消息端