一、简介

　　消息队列就是基础数据结构中的“先进先出”的一种数据机构，

　　RabbitMQ是一个开源的AMQP实现，服务器端用Erlang语言编写，支持多种客户端，如：Python、Ruby、Java、JMS、C等，支持AJAX。

　　用于在分布式系统中存储转发消息，在易用性、扩展性、高可用性等方面表现不俗。

二、RabbitMQ的作用

　　1.主要应用于应用解耦

以电商应用为例，应用中有订单系统、库存系统、物流系统、支付系统。用户创建订单后，如果耦合调用库存系统、物流系统、支付系统，任何一个子系统出了故障，都会造成下单操作异常。

当转变成基于消息队列的方式后，系统间调用的问题会减少很多，比如物流系统因为发生故障，需要几分钟来修复。在这几分钟的时间里，物流系统要处理的内存被缓存在消息队列中，用户
的下单操作可以正常完成。当物流系统恢复后，继续处理订单信息即可，中单用户感受不到物流系统的故障。提升系统的可用性

　　　　　　　　

　　2.流量削峰

举个栗子，如果订单系统最多能处理一万次订单，这个处理能力应付正常时段的下单时绰绰有余，正常时段我们下单一秒后就能返回结果。但是在高峰期，如果有两万次下单操作系统
是处理不了的，只能限制订单超过一万后不允许用户下单。

使用消息队列做缓冲，我们可以取消这个限制，把一秒内下的订单分散成一段时间来处理，这事有些用户可能在下单十几秒后才能收到下单成功的操作，但是比不能下单的体验要好。

 　　3.消息分发

　　　　生产者只负责生产消息，消费者只要监听了生产者 ，那么生产者发的消息就能被接收。

　　　　　　

　　4.异步消息

使用消息总线，可以很方便解决这个问题，A调用B服务后，只需要监听B处理完成的消息，当B处理完成后，会发送一条消息给MQ，MQ会将此消息转发给A服务。

这样A服务既不用循环调用B的查询api，也不用提供callback api。同样B服务也不用做这些操作。A服务还能及时的得到异步处理成功的消息

　　　　

　　5.常见消息队列及比较

　　　　

　　　　总结：

Kafka在于分布式架构，RabbitMQ基于AMQP协议来实现，RocketMQ/思路来源于kafka，改成了主从结构，在事务性可靠性方面做了优化。广泛来说，电商、
金融等对事务性要求很高的，可以考虑RabbitMQ和RocketMQ，对性能要求高的可考虑Kafka

三、安装

　　服务端安装：

# 原生：
# 安装配置epel源
# 安装erlang
yum -y install erlang
# 安装RabbitMQ
yum -y install rabbitmq-server


# 使用Docker
docker pull rabbitmq:management
docker run -di --name Myrabbitmq -e RABBITMQ_DEFAULT_USER=admin -e RABBITMQ_DEFAULT_PASS=admin -p 15672:15672 -p 5672:5672 rabbitmq:management

　　客户端：

pip3 install pika

四、使用

　　基本使用：

# 生产者

import pika

# 拿到连接对象
# 有用户名密码的情况
# connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200'))

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))

# 拿到channel对象
channel = connection.channel()

# 声明一个队列
channel.queue_declare(queue='hello')  # 指定队列名字

# 生产者向队列中放一条消息
channel.basic_publish(exchange='',
                      routing_key='hello',
                      body='hello world')
print(" Sent 'Hello World!'")
# 关闭连接
connection.close()

# 消费者
import pika


def main():
    # 无密码
    # connection = pika.BlockingConnection(pika.ConnectionParameters(host='10.0.0.200'))
    credentials = pika.PlainCredentials("admin", "admin")
    connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
    channel = connection.channel()

    channel.queue_declare(queue='hello')

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

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

    channel.start_consuming()


if __name__ == '__main__':
    main()

　　消息确认（保障安全）

import pika

# 无密码
# connection = pika.BlockingConnection(pika.ConnectionParameters('127.0.0.1'))

# 有密码
credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()
# 声明一个队列(创建一个队列)
channel.queue_declare(queue='qjk')

channel.basic_publish(exchange='',
                      routing_key='qjk',  # 消息队列名称
                      body='hello world')
connection.close()

生产者

import pika


def main():
    credentials = pika.PlainCredentials("admin", "admin")
    connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
    channel = connection.channel()

    # 声明一个队列(创建一个队列)
    channel.queue_declare(queue='qjk')

    def callback(ch, method, properties, body):
        print("消费者接受到了任务: %r" % body)
        # 真正的消息处理完了，再发确认
        ch.basic_ack(delivery_tag=method.delivery_tag)

    # 不会自动回复确认消息，
    # auto_ack=True，队列收到确认，就会自动把消费过的消息删除
    channel.basic_consume(queue='qjk', on_message_callback=callback, auto_ack=False)

    channel.start_consuming()


if __name__ == '__main__':
    main()

消费者

　　持久化

import pika

# 无密码
# connection = pika.BlockingConnection(pika.ConnectionParameters('127.0.0.1'))

# 有密码
credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()
# 声明一个队列(创建一个队列)
channel.queue_declare(queue='qjk', durable=True)  # 指定队列持久化

channel.basic_publish(exchange='',
                      routing_key='qjk',  # 消息队列名称
                      body='hello world',
                      properties=pika.BasicProperties(
                          delivery_mode=2, )  # 指定消息持久化
                      )
connection.close()

生产者

import pika


def main():
    credentials = pika.PlainCredentials("admin", "admin")
    connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
    channel = connection.channel()

    # 声明一个队列(创建一个队列)
    channel.queue_declare(queue='qjk', durable=True)  # 指定队列持久化

    def callback(ch, method, properties, body):
        print("消费者接受到了任务: %r" % body)
        # 真正的消息处理完了，再发确认
        ch.basic_ack(delivery_tag=method.delivery_tag)

    # 不会自动回复确认消息，
    # auto_ack=True，队列收到确认，就会自动把消费过的消息删除
    channel.basic_consume(queue='qjk', on_message_callback=callback, auto_ack=False)

    channel.start_consuming()


if __name__ == '__main__':
    main()

消费者

　　闲置消费

import pika

# 无密码
# connection = pika.BlockingConnection(pika.ConnectionParameters('127.0.0.1'))

# 有密码
credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()
# 声明一个队列(创建一个队列)
channel.queue_declare(queue='qjk', durable=True)  # 指定队列持久化

channel.basic_publish(exchange='',
                      routing_key='qjk',  # 消息队列名称
                      body='hello world',
                      properties=pika.BasicProperties(
                          delivery_mode=2, )  # 指定消息持久化
                      )
connection.close()

生产者

import pika


def main():
    credentials = pika.PlainCredentials("admin", "admin")
    connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
    channel = connection.channel()

    # 声明一个队列(创建一个队列)
    channel.queue_declare(queue='qjk')

    def callback(ch, method, properties, body):
        print("消费者接受到了任务: %r" % body)
        # 真正的消息处理完了，再发确认
        ch.basic_ack(delivery_tag=method.delivery_tag)

    # 不会自动回复确认消息，
    # auto_ack=True，队列收到确认，就会自动把消费过的消息删除
    channel.basic_consume(queue='qjk', on_message_callback=callback, auto_ack=False)
    channel.basic_qos(prefetch_count=1)  # 谁闲置谁获取，没必要按照顺序一个一个来

    channel.start_consuming()


if __name__ == '__main__':
    main()

消费者

　　发布订阅

import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

# 声明队列没有指定名字，指定了exchange
channel.exchange_declare(exchange='logs', exchange_type='fanout')

message = "info: Hello World!"
channel.basic_publish(exchange='logs', routing_key='', body=message)
print(" [x] Sent %r" % message)
connection.close()

发布者

# 起多个都能收到消息

import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

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

result = channel.queue_declare(queue='', exclusive=True)
# 随机的名字
queue_name = result.method.queue
print(queue_name)

# 绑定
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(
    queue=queue_name, on_message_callback=callback, auto_ack=True)

channel.start_consuming()

订阅者

　　发布订阅（高级之Routing按关键字匹配)

import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

# 声明队列没有指定名字，指定了exchange
channel.exchange_declare(exchange='qjk123', exchange_type='direct')

message = "info: asdfasdfasdfsadfasdf World!"
channel.basic_publish(exchange='qjk123', routing_key='bnb', body=message)  # 指定关键字
print(" [x] Sent %r" % message)
connection.close()

发布者

import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

channel.exchange_declare(exchange='qjk123', exchange_type='direct')

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

channel.queue_bind(exchange='qjk123', queue=queue_name, routing_key='nb')

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


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


channel.basic_consume(
    queue=queue_name, on_message_callback=callback, auto_ack=True)

channel.start_consuming()

订阅者1

import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

channel.exchange_declare(exchange='qjk123', exchange_type='direct')

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

channel.queue_bind(exchange='qjk123', queue=queue_name, routing_key='nb')
channel.queue_bind(exchange='qjk123', queue=queue_name, routing_key='bnb')

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


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


channel.basic_consume(
    queue=queue_name, on_message_callback=callback, auto_ack=True)

channel.start_consuming()

订阅者2

　　发布订阅高级之Topic(按关键字模糊匹配)　　　

　　　　*  只能加一个单词

　　　　#  可以加任意单词字符

import pika


credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

# 声明队列没有指定名字，指定了exchange
channel.exchange_declare(exchange='m3', exchange_type='topic')

message = "info: asdfasdfasdfsadfasdf World!"
channel.basic_publish(exchange='m3', routing_key='qjk.dd.dd', body=message)
print(" [x] Sent %r" % message)
connection.close()

发布者

# 收不到消息
import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

channel.exchange_declare(exchange='m3', exchange_type='topic')

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

channel.queue_bind(exchange='m3', queue=queue_name, routing_key='qjk.*')

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


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


channel.basic_consume(
    queue=queue_name, on_message_callback=callback, auto_ack=True)

channel.start_consuming()

订阅者1

# 可以收到消息
import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
channel = connection.channel()

channel.exchange_declare(exchange='m3', exchange_type='topic')

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

channel.queue_bind(exchange='m3', queue=queue_name, routing_key='qjk.#')
print(' [*] Waiting for logs. To exit press CTRL+C')


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


channel.basic_consume(
    queue=queue_name, on_message_callback=callback, auto_ack=True)

channel.start_consuming()

订阅者2

五、三种方式实现RPC

　　1.RabbitMQ实现RPC

import pika
import uuid


class FibonacciRpcClient(object):

    def __init__(self):

        self.credentials = pika.PlainCredentials("admin", "admin")
        self.connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=self.credentials))
        self.channel = self.connection.channel()

        result = self.channel.queue_declare(queue='', exclusive=True)
        self.callback_queue = result.method.queue

        self.channel.basic_consume(
            queue=self.callback_queue,
            on_message_callback=self.on_response,
            auto_ack=True)

    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.BasicProperties(
                reply_to=self.callback_queue,
                correlation_id=self.corr_id,
            ),
            body=str(n))
        while self.response is None:
            self.connection.process_data_events()
        return int(self.response)


fibonacci_rpc = FibonacciRpcClient()

print(" [x] Requesting fib(30)")
response = fibonacci_rpc.call(20)  # 外界看上去，就像调用本地的call()函数一样
print(" [.] Got %r" % response)

客户端

import pika

credentials = pika.PlainCredentials("admin", "admin")
connection = pika.BlockingConnection(pika.ConnectionParameters('10.0.0.200', credentials=credentials))
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.reply_to,
                     properties=pika.BasicProperties(correlation_id= \
                                                         props.correlation_id),
                     body=str(response))
    ch.basic_ack(delivery_tag=method.delivery_tag)


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

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

服务端

　　2.内置包SimpleXMLRPCServer实现

from xmlrpc.client import ServerProxy


# SimpleXMLRPCServer
def xmlrpc_client():
    print('xmlrpc client')
    c = ServerProxy('http://localhost:4242')
    data = {'client:' + str(i): i for i in range(100)}
    start = time.clock()
    for i in range(100):
        a = c.getObj()
        print(a)
    for i in range(100):
        c.sendObj(data)
    print('xmlrpc total time %s' % (time.clock() - start))


if __name__ == '__main__':
    xmlrpc_client()

客户端

from xmlrpc.server import SimpleXMLRPCServer


class RPCServer(object):

    def __init__(self):
        super(RPCServer, self).__init__()
        print(self)
        self.send_data = {'server:' + str(i): i for i in range(100)}
        self.recv_data = None

    def getObj(self):
        print('get data')
        return self.send_data

    def sendObj(self, data):
        print('send data')
        self.recv_data = data
        print(self.recv_data)


# SimpleXMLRPCServer
server = SimpleXMLRPCServer(('localhost', 4242), allow_none=True)
server.register_introspection_functions()
server.register_instance(RPCServer())
server.serve_forever()

服务端

　　3.ZeroRPC实现

　　　　安装：pip3 install zerorpc

import zerorpc
import time


# zerorpc
def zerorpc_client():
    print('zerorpc client')
    c = zerorpc.Client()
    c.connect('tcp://127.0.0.1:4243')
    data = {'client:' + str(i): i for i in range(100)}
    start = time.clock()
    for i in range(100):
        a = c.getObj()
        print(a)
    for i in range(100):
        c.sendObj(data)

    print('total time %s' % (time.clock() - start))


if __name__ == '__main__':
    zerorpc_client()

客户端

import zerorpc


class RPCServer(object):

    def __init__(self):
        super(RPCServer, self).__init__()
        print(self)
        self.send_data = {'server:' + str(i): i for i in range(100)}
        self.recv_data = None

    def getObj(self):
        print('get data')
        return self.send_data

    def sendObj(self, data):
        print('send data')
        self.recv_data = data
        print(self.recv_data)


# zerorpc
s = zerorpc.Server(RPCServer())
s.bind('tcp://0.0.0.0:4243')
s.run()

服务端