python操作——RabbitMQ

RabbitMQ是一个在AMQP基础上完整的，可服用的企业消息系统。他遵循Mozilla Public License开源协议。

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，直接调用通常是用于诸如远程过程调用的技术。

队列的使用除去了接收和发送应用程序同时执行的要求。

RabbitMQ安装

安装配置epel源
   $ rpm -ivh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm

安装erlang
   $ yum -y install erlang

安装RabbitMQ
   $ yum -y install rabbitmq-server

注意：service rabbitmq-server start/stop

安装API

pip install pika
or
easy_install pika
or
源码

https://pypi.python.org/pypi/pika

使用API操作RabbitMQ

基于Queue实现生产者消费者模型

 #!/usr/bin/env python
 # -*- coding:utf-8 -*-
 import Queue
 import 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()

基于Queue

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。

生产者：

 #!/usr/bin/env python
 import pika

 # ######################### 生产者 #########################

 connection = pika.BlockingConnection(pika.ConnectionParameters(
         host='localhost'))
 channel = connection.channel()

 channel.queue_declare(queue='hello')

 channel.basic_publish(exchange='',
                       routing_key='hello',
                       body='Hello World!')
 print(" [x] Sent 'Hello World!'")
 connection.close()

消费者：

 #!/usr/bin/env python
 import pika

 # ########################## 消费者 ##########################

 connection = pika.BlockingConnection(pika.ConnectionParameters(
         host='localhost'))
 channel = connection.channel()

 channel.queue_declare(queue='hello')

 def callback(ch, method, properties, body):
     print(" [x] Received %r" % body)

 channel.basic_consume(callback,
                       queue='hello',
                       no_ack=True)

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

1.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。

import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(
        host='10.211.55.4'))
channel = connection.channel()

channel.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_consume(callback,
                      queue='hello',
                      no_ack=False)

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

消费者

2.durable消息不丢失

#!/usr/bin/env python
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(host='10.211.55.4'))
channel = connection.channel()

# make message persistent
channel.queue_declare(queue='hello', durable=True)

channel.basic_publish(exchange='',
                      routing_key='hello',
                      body='Hello World!',
                      properties=pika.BasicProperties(
                          delivery_mode=2, # make message persistent
                      ))
print(" [x] Sent 'Hello World!'")
connection.close()

生产者

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(host='10.211.55.4'))
channel = connection.channel()

# make message persistent
channel.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)

channel.basic_consume(callback,
                      queue='hello',
                      no_ack=False)

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

消费者

3.消费获取顺序

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 pika

connection = pika.BlockingConnection(pika.ConnectionParameters(host='10.211.55.4'))
channel = connection.channel()

# make message persistent
channel.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)

channel.basic_consume(callback,
                      queue='hello',
                      no_ack=False)

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

消费者

4.发布订阅

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 python
import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(
        host='localhost'))
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] Sent %r" % message)
connection.close()

发布者

#!/usr/bin/env python
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters(
        host='localhost'))
channel = connection.channel()

channel.exchange_declare(exchange='logs',
                         type='fanout')

result = channel.queue_declare(exclusive=True)
queue_name = result.method.queue

channel.queue_bind(exchange='logs',
                   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,
                      queue=queue_name,
                      no_ack=True)

channel.start_consuming()

订阅者

5.关键字发送

exchange type = direct

之前事例，发送消息时明确指定某个队列并向其中发送消息，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。

 #!/usr/bin/env python
 import pika
 import sys

 connection = 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.queue

 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)

 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()

消费者

 #!/usr/bin/env python
 import pika
 import sys

 connection = 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()

生产者

6.模糊匹配

exchange type = topic

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。

• # 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 python
 import pika
 import sys

 connection = 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.queue

 binding_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()

消费者

 #!/usr/bin/env python
 import pika
 import sys

 connection = 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()

生产者

 sudo rabbitmqctl add_user alex 123
 # 设置用户为administrator角色
 sudo rabbitmqctl set_user_tags alex administrator
 # 设置权限
 sudo rabbitmqctl set_permissions -p "/" alex '.''.''.'

 # 然后重启rabbiMQ服务
 sudo /etc/init.d/rabbitmq-server restart

 # 然后可以使用刚才的用户远程连接rabbitmq server了。

 ------------------------------
 credentials = pika.PlainCredentials("alex","")

 connection = pika.BlockingConnection(pika.ConnectionParameters('192.168.14.47',credentials=credentials))

注意事项