RabbitMQ、Rdis

RabbitMQ

RabbitMQ:官方网址:http://www.rabbitmq.com/

Install Erlang

# rpm -ivh erlang-18.3-1.el6.x86_64.rpm 

Install RabbitMQ Server

rpm -ivh rabbitmq-server-3.6.2-1.noarch.rpm

1、Hello World!

生产者

import pika

credentials = pika.PlainCredentials('guest', 'guest')  # 使用用户名密码进行验证
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))
channel = connection.channel()  # 声明一个通道

channel.queue_declare(queue='test.queue')  # 声明一个queue
channel.basic_publish(exchange='', routing_key='test.queue', body='Hello World!')
print(" [x] Sent 'Hello World!'")
connection.close()

消费者

import pika

credentials = pika.PlainCredentials('guest', 'guest')  # 使用用户名密码进行验证
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))

channel = connection.channel()

channel.queue_declare(queue='test.queue')

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

channel.basic_consume(callback, queue='test.queue', no_ack=True)  # callback如果收到消息就调用callback函数处理消息
#  no_ack=True 指客户端处理完消息后，不跟服务器进行确认，这个参数在生成一定不能是用

channel.basic_qos(prefetch_count=1)  # 设置接收端控制消息处理机制
print(' [*] Waiting for messages. To exit press CTRL+C')

channel.start_consuming()

acknowledgments

Message acknowledgments are turned on by default，在前面的代码内，我们为了举例，no_ack=True，这个参数在生产环境强烈建议去掉。

下面展示一段消费者代码:

import pika

credentials = pika.PlainCredentials('guest', 'guest')  # 使用用户名密码进行验证
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))

channel = connection.channel()

channel.queue_declare(queue='test.queue', durable=True)

def callback(ch, method, properties, body):
    print(" [x] Received %r" % body)
    ch.basic_ack(delivery_tag=method.delivery_tag)  # 代表告诉消息服务器我处理完毕，你可以把消息删除了

channel.basic_consume(callback, queue='test.queue')  # callback如果收到消息就调用callback函数处理消息

channel.basic_qos(prefetch_count=1)  # 设置接收端控制消息处理机制
print(' [*] Waiting for messages. To exit press CTRL+C')

channel.start_consuming()

消息的持久化

First, we need to make sure that RabbitMQ will never lose our queue. In order to do so, we need to declare it as durable:

channel.queue_declare(queue='hello', durable=True)

This queue_declare change needs to be applied to both the producer and consumer code.

Now we need to mark our messages as persistent - by supplying a delivery_mode property with a value 2.

channel.basic_publish(exchange='',
                      routing_key="task_queue",
                      body=message,
                      properties=pika.BasicProperties(
                         delivery_mode = 2, # make message persistent
                      ))

例1:

import pika

credentials = pika.PlainCredentials('guest', 'guest')  # 使用用户名密码进行验证
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))
channel = connection.channel()  # 声明一个通道

channel.queue_declare(queue='test.queue', durable=True)  # 声明一个queue
properties = pika.BasicProperties(delivery_mode=2)  # 消息持久化
channel.basic_publish(exchange='', routing_key='test.queue', body='Hello World!', properties=properties)
print(" [x] Sent 'Hello World!'")
connection.close()

消息发布\订阅

Exchange在定义的时候是有类型的，以决定到底是哪些Queue符合条件，可以接收消息

fanout: 所有bind到此exchange的queue都可以接收消息
direct: 通过routingKey和exchange决定的那个唯一的queue可以接收消息
topic:所有符合routingKey(此时可以是一个表达式)的routingKey所bind的queue可以接收消息

注意:消息不会存在Exchange里面。

exchange type=fanout

生产者:

import pika
import sys

credentials = pika.PlainCredentials('guest', 'guest')  # 使用用户名密码进行验证
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))
channel = connection.channel()

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

message = ' '.join(sys.argv[1:]) or "info: Hello Worlcccc!"

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

消费者:

import pika

credentials = pika.PlainCredentials('guest', 'guest')  # 使用用户名密码进行验证
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))
channel = connection.channel()

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

result = channel.queue_declare(exclusive=True)  # 不指定queue名字,rabbit会随机分配一个名字,exclusive=True会在使用此queue的消费者断开后,自动将queue删除
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)
channel.start_consuming()

exchange type=direct

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。

生产者

import pika
import sys

credentials = pika.PlainCredentials('guest', 'guest')
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))
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()

消费者

import pika
import sys

credentials = pika.PlainCredentials('guest', 'guest')
connection = pika.BlockingConnection(
    pika.ConnectionParameters(host='192.168.33.35', port=5672, credentials=credentials))
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)

channel.start_consuming()

exchange type=topic

生产者:

消费者:

#:代表接收所有消息

Remote procedure call (RPC)

RabbitMQ常用命令:

列出所有queue，The default value is "/"

1、rabbitmqctl list_queues

修改用户的密码

2、change_password <username> <newpassword>

Redis

Redis是缓存数据库，

import redis

r = redis.Redis(host='192.168.33.35', port=6379)
r.set('foo', 'Bar')
print(r.get('foo'))

连接池方式:

import redis

pool = redis.ConnectionPool(host='192.168.33.35', port=6379)

r = redis.Redis(connection_pool=pool)
r.set('foo', 'Bar')
print(r.get('foo'))

set(name, value, ex=None, px=None, nx=False, xx=False)

在Redis中设置值，默认，不存在则创建，存在则修改

参数：

     ex，过期时间（秒）

     px，过期时间（毫秒）

     nx，如果设置为True，则只有name不存在时，当前set操作才执行

     xx，如果设置为True，则只有name存在时，岗前set操作才执行

Redis常用命令介绍