rabbitmq在centos7下安装
一. RabbitMQ队列
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#消息中间件 -消息队列 - 异步 提交的任务不需要实时得到结果或回应 python线程Q 实现了在同一个进程间不同线程间的交互 python线程Q 也可以实现进程间Q的通信 |
a. 安装
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#Centos7 安装 #注意/etc/hosts文件 ip和主机名对应 wget https: / / github.com / rabbitmq / rabbitmq - server / releases / download / rabbitmq_v3_6_10 / rabbitmq - server - 3.6 . 10 - 1.el7 .noarch.rpm yum install epel - release - y yum install rabbitmq - server - 3.6 . 10 - 1.el7 .noarch.rpm rabbitmq - plugins enable rabbitmq_management cp / usr / share / doc / rabbitmq - server - 3.6 . 10 / rabbitmq.config.example / etc / rabbitmq / rabbitmq.config systemctl restart rabbitmq - server systemctl status rabbitmq - server #创建用户 授权 rabbitmqctl add_user alex alex3714 rabbitmqctl set_permissions - p / alex ".*" ".*" ".*" |
启动失败:
[root@openstack ~]# systemctl start rabbitmq-server.service Job for rabbitmq-server.service failed. See ‘systemctl status rabbitmq-server.service’ and ‘journalctl -xn’ for details. [root@openstack ~]# systemctl status rabbitmq-server.service rabbitmq-server.service – RabbitMQ broker Loaded: loaded (/usr/lib/systemd/system/rabbitmq-server.service; enabled) Active: failed (Result: exit-code) since 六 2016-04-30 23:19:21 CST; 8s ago Process: 3593 ExecStop=/usr/lib/rabbitmq/bin/rabbitmqctl stop (code=exited, status=2) Process: 3563 ExecStart=/usr/lib/rabbitmq/bin/rabbitmq-server (code=exited, status=1/FAILURE) Main PID: 3563 (code=exited, status=1/FAILURE) 4月 30 23:19:21 openstack rabbitmqctl[3593]: * epmd reports: node ‘rabbit’ not running at all 4月 30 23:19:21 openstack rabbitmqctl[3593]: no other nodes on openstack 4月 30 23:19:21 openstack rabbitmqctl[3593]: * suggestion: start the node 4月 30 23:19:21 openstack rabbitmqctl[3593]: current node details: 4月 30 23:19:21 openstack rabbitmqctl[3593]: – node name: rabbitmqctl3593@openstack 4月 30 23:19:21 openstack rabbitmqctl[3593]: – home dir: /var/lib/rabbitmq 4月 30 23:19:21 openstack rabbitmqctl[3593]: – cookie hash: DuHinHyRsf96Yx7NcAaAuQ== 4月 30 23:19:21 openstack systemd[1]: rabbitmq-server.service: control process exited, code=exited status=2 4月 30 23:19:21 openstack systemd[1]: Failed to start RabbitMQ broker. 4月 30 23:19:21 openstack systemd[1]: Unit rabbitmq-server.service entered failed state.
解决办法:
firewall-cmd --permanent --add-port=5672/tcp firewall-cmd --reload setsebool -P nis_enabled 1
systemctl start rabbitmq-server再次启动:
[root@oldboy_zny rabbitmq]# systemctl start rabbitmq-server
[root@oldboy_zny rabbitmq]# systemctl status rabbitmq-server
rabbitmq-server.service - RabbitMQ broker
Loaded: loaded (/usr/lib/systemd/system/rabbitmq-server.service; enabled)
Active: active (running) since 一 2018-03-05 10:33:48 CST; 8s ago
Process: 22014 ExecStop=/usr/sbin/rabbitmqctl stop (code=exited, status=0/SUCCESS)
Main PID: 22152 (beam)
Status: "Initialized"
CGroup: /system.slice/rabbitmq-server.service
├─22152 /usr/lib64/erlang/erts-5.10.4/bin/beam -W w -A 64 -P 1048576 -t 5000000 -stbt db -zdbbl 32000 -K true -- -root /usr/lib64/erlang...
├─22441 inet_gethost 4
└─22442 inet_gethost 4
3月 05 10:33:47 oldboy_zny rabbitmq-server[22152]: ## ##
3月 05 10:33:47 oldboy_zny rabbitmq-server[22152]: ########## Logs: /var/log/rabbitmq/rabbit@oldboy_zny.log
3月 05 10:33:47 oldboy_zny rabbitmq-server[22152]: ###### ## /var/log/rabbitmq/rabbit@oldboy_zny-sasl.log
3月 05 10:33:47 oldboy_zny rabbitmq-server[22152]: ##########
3月 05 10:33:47 oldboy_zny rabbitmq-server[22152]: Starting broker...
3月 05 10:33:48 oldboy_zny rabbitmq-server[22152]: systemd unit for activation check: "bin"
3月 05 10:33:48 oldboy_zny rabbitmq-server[22152]: 'systemctl' unavailable, falling back to sleep
3月 05 10:33:48 oldboy_zny systemd[1]: Started RabbitMQ broker.
3月 05 10:33:49 oldboy_zny python[22447]: SELinux is preventing /usr/bin/bash from getattr access on the file .
***** Plugin catchall (100. confidence) suggests **************************...
3月 05 10:33:53 oldboy_zny rabbitmq-server[22152]: completed with 6 plugins.
Hint: Some lines were ellipsized, use -l to show in full.
b. 创建用户 授权
#远程连接rabbitmq server的话,需要配置权限 #创建用户 rabbitmqctl add_user alex alex3714 #同时还要配置权限,允许从外面访问 rabbitmqctl set_permissions -p / alex ".*" ".*" ".*" set_permissions [-p vhost] {user} {conf} {write} {read} vhost The name of the virtual host to which to grant the user access, defaulting to /. user The name of the user to grant access to the specified virtual host. conf A regular expression matching resource names for which the user is granted configure permissions. write A regular expression matching resource names for which the user is granted write permissions. read A regular expression matching resource names for which the user is granted read permissions.
c. python rabbitMQ module 安装
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pip install pika or easy_install pika or 源码 https: / / pypi.python.org / pypi / pika |
二. 事例
参考博客:http://www.cnblogs.com/yuanchenqi/articles/8507109.html
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注意: 一般申明队列(如下代码)只需要在服务端申明,但客户端也可以申明,是防止如果服务端没有启动,客户端先启动后没有队列会报错 此时服务端如果有相同代码,会检查,如果有相同队列就不创建 channel.queue_declare(queue = 'hello' ) |
a. 服务端和客户端一对一
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#查看队列 # rabbitmqctl list_queues #客户端再次申明队列是因为客户端要清楚去哪里取数据 channel.queue_declare(queue = 'hello' ) |
import pika credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('192.168.11.106',credentials=credentials)) #建立socket channel = connection.channel() #创建rabbitmq协议通道 channel.queue_declare(queue='hello') #通过通道生成一个队列 channel.basic_publish(exchange='', routing_key='hello', #队列 body='Hello World!') #内容 print(" [x] Sent 'Hello World!'") connection.close()
import pika credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('192.168.11.106',credentials=credentials)) #建立socket channel = connection.channel() channel.queue_declare(queue='hello') def callback(ch, method, properties, body): print(ch) #上面channel = connection.channel()对象 print(method) #除了服务端本身的数据,还带一些参数 print(properties) #属性 print(body) #byte数据 channel.basic_consume(callback, queue='hello', no_ack=True) print(' Waiting for messages. To exit press CTRL+C') channel.start_consuming()
b. 消息持久化
1. 模拟客户端中断 观察服务端队列的数据会不会返回(不会)
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#- 开启一个服务端,两个客户端 #- 服务端向队列中存放一个值,一客户端从队列中取到数据,在睡20秒期间中断,表示出错,它不会报告给服务端 #- 这时队列中为零,另一客户端也不会取到值 # no_ack=True 表示客户端处理完了不需要向服务端确认消息 |
import pika credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('192.168.11.106',credentials=credentials)) #建立socket channel = connection.channel() #创建rabbitmq协议通道 channel.queue_declare(queue='hello') #通过通道生成一个队列 channel.basic_publish(exchange='', routing_key='hello', #队列 body='Hello World!') #内容 print(" [x] Sent 'Hello World!'") connection.close()
import pika import time credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('192.168.11.106',credentials=credentials)) #建立socket channel = connection.channel() channel.queue_declare(queue='hello') def callback(ch, method, properties, body): print("received msg...start process",body) time.sleep(10) print("end process...") channel.basic_consume(callback, queue='hello', no_ack=True) print(' Waiting for messages. To exit press CTRL+C') channel.start_consuming()
2. 模拟客户端中断 观察服务端队列的数据会不会返回(会)
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#1. 生产者端发消息时,加参数 消息持久化 properties = pika.BasicProperties( delivery_mode = 2 , # make message persistent ), #2. 消费者端,消息处理完毕时,发送确认包 ch.basic_ack(delivery_tag = method.delivery_tag) channel.basic_consume(callback, #取到消息后,调用callback 函数 queue = 'task1' ,) #no_ack=True) #消息处理后,不向rabbit-server确认消息已消费完毕 #- 开启一个服务端,两个客户端 #- 服务端向队列中存放一个值,一客户端从队列中取到数据,在睡20秒期间中断,表示出错,它会报给服务端,服务端队列还有值 #- 这时启动另一客户端还可以取到值 |
import pika credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('192.168.11.106',credentials=credentials)) #建立socket channel = connection.channel() #创建rabbitmq协议通道 channel.queue_declare(queue='hello') #通过通道生成一个队列 channel.basic_publish(exchange='', routing_key='hello', #队列 properties=pika.BasicProperties( delivery_mode=2, # make message persistent ), body='Hello World!') #内容 print(" [x] Sent 'Hello World!'") connection.close()
import pika import time credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('192.168.11.106',credentials=credentials)) #建立socket channel = connection.channel() channel.queue_declare(queue='hello') def callback(ch, method, properties, body): print("received msg...start process",body) time.sleep(10) print("end process...") ch.basic_ack(delivery_tag=method.delivery_tag) channel.basic_consume(callback, queue='hello', ) print(' Waiting for messages. To exit press CTRL+C') channel.start_consuming()
c. 队列持久化
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#队列持久化 channel.queue_declare(queue = 'hello' ,durable = True ) systemctl restart rabbitmq - server #重启服务发现hello队列还在,但是消息不在 rabbitmqctl list_queues #hello #队列和消息持久化 channel.queue_declare(queue = 'hello' ,durable = True ) properties = pika.BasicProperties( delivery_mode = 2 , # make message persistent ), systemctl restart rabbitmq - server #重启服务发现队列和消息都还在 rabbitmqctl list_queues #hello 6 |
import pika credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('192.168.11.106',credentials=credentials)) #建立socket channel = connection.channel() #创建rabbitmq协议通道 channel.queue_declare(queue='hello',durable=True) #通过通道生成一个队列 channel.basic_publish(exchange='', routing_key='hello', #队列 properties=pika.BasicProperties( delivery_mode=2, # make message persistent ), body='Hello World!') #内容 print(" [x] Sent 'Hello World!'") connection.close()
d. fanout 广播
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#服务端: - 不需要申明队列 #客户端: - 每个客户端都需要申明一个队列,自动设置队列名称,收听广播,当收听完后queue删除 - 把队列绑定到exchange上 #注意:客户端先打开,服务端再打开,客户端会收到消息 #应用: - 微博粉丝在线,博主发消息,粉丝可以收到 #如果服务端先启动向exchange发消息,这时客户端没有启动,没有队列保存数据(exchange不负责保存数据) #这时数据会丢,队列中没有数据 #exchange只负责转发 |
import pika import sys import time credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('172.16.42.128',credentials=credentials)) #建立socket channel = connection.channel() #创建rabbitmq协议通道 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(" Send %r" % message) connection.close()
import pika import time credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('172.16.42.128',credentials=credentials)) #建立socket channel = connection.channel() channel.exchange_declare(exchange='logs', type='fanout') queue_obj = channel.queue_declare(exclusive=True) #随机创建一个队列对象 exclusive=True会在使用此queue的消费者断开后,自动将queue删除 queue_name = queue_obj.method.queue #不指定queue名字,rabbit会随机分配一个名字, channel.queue_bind(exchange='logs',queue=queue_name) #把queue绑定到exchange 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()
e. direct 组播
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#客户端一: - python3 receive1.py info #客户端二: - python3 receive1.py error #客户端三: - python3 receive1.py warning #客户端四: - python3 receive1.py warning error info #服务端: - python3 receive1.py warning |
import pika import sys import time credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('172.16.42.128',credentials=credentials)) #建立socket channel = connection.channel() #创建rabbitmq协议通道 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(" Send %r:%r" % (severity, message)) connection.close()
import pika import time import sys credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('172.16.42.128',credentials=credentials)) #建立socket 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()
f. topic 规则传播
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#客户端一: - python3 receive1.py * .django #客户端二: - python3 receive1.py mysql.error #客户端三: - python3 receive1.py mysql. * #服务端: - python3 receive1.py #匹配相应的客户端 |
import pika import time import sys credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('172.16.42.128',credentials=credentials)) #建立socket 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: print(sys.argv[1:]) 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()
import pika import sys import time credentials = pika.PlainCredentials("egon","egon123") #授权的账号 密码 connection = pika.BlockingConnection( pika.ConnectionParameters('172.16.42.128',credentials=credentials)) #建立socket channel = connection.channel() #创建rabbitmq协议通道 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))
以生产者消费者举例四种模式:
生产者:
# ! /usr/bin/env python # -*- coding: utf-8 -*- # Author : 张宁阳 # date: 2018/3/6 # ######################### 简答模式生产者 ######################### import pika connection = pika.BlockingConnection(pika.ConnectionParameters( host='192.168.20.56',port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() channel.queue_declare(queue='hello') channel.basic_publish(exchange='', routing_key='hello', body='ssssssssssssss') print(" 已经 发送 'ssssssssssssssssss'") connection.close() ######################基于exchang分发模式的生产者########################### import pika connection = pika.BlockingConnection(pika.ConnectionParameters( host='192.168.20.56',port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() 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() ##########基于exchange关键字模式的生产者############## import pika connection = pika.BlockingConnection(pika.ConnectionParameters( host='192.168.20.56',port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() channel.exchange_declare(exchange='direct_logs', exchange_type='direct') message = "info: Hello World!" channel.basic_publish(exchange='direct_logs', routing_key='info',#关键字:info、error、warning body=message) print(" [x] Sent %r" % message) connection.close() ##########基于exchange模糊匹配模式的生产者############## import pika connection = pika.BlockingConnection(pika.ConnectionParameters( host='192.168.20.56',port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() channel.exchange_declare(exchange='topic_logs', exchange_type='topic') message = "info: Hello World!" #routing_key="模糊匹配字符" routing_keys=["old.boy.python ","old.boy"] for key in routing_keys: channel.basic_publish(exchange='topic_logs', routing_key=key, body=message) print(" [x] Sent %r" % message) connection.close()
消费者
# ! /usr/bin/env python # -*- coding: utf-8 -*- # Author : 张宁阳 # date: 2018/3/6 ##########################基于简单模式的 消费者 ########################## import pika connection = pika.BlockingConnection(pika.ConnectionParameters(host='192.168.20.56',port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() channel.queue_declare(queue='hello') def callback(ch, method, properties, body): print(" 已经 接受 %r" % body) channel.basic_consume(callback, queue='hello', no_ack=True) print(' [*] Waiting for messages. To exit press CTRL+C') channel.start_consuming() ##############基于exchange分发模式消费者##################### import pika connection = pika.BlockingConnection(pika.ConnectionParameters( host='192.168.20.56',port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() channel.exchange_declare(exchange='logs', exchange_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() ##########################基于exchange的关键字模式的 消费者 ########################## import pika connection = pika.BlockingConnection(pika.ConnectionParameters(host='192.168.20.56', port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() # 生成交换机 channel.exchange_declare(exchange='direct_logs', exchange_type='direct') # 创建的队列 result = channel.queue_declare(exclusive=True) # 创建的队列的随机名称 queue_name = result.method.queue # 给队列与direct_logs这个交换机绑定三个关键字 severities = ["info", "warning", "error"] 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() ##########################基于exchange的模糊匹配模式的 消费者 ########################## import pika import sys connection = pika.BlockingConnection(pika.ConnectionParameters(host='192.168.20.56', port=5672, credentials=pika.credentials.PlainCredentials( username='alex', password='alex3714' ))) channel = connection.channel() channel.exchange_declare(exchange='topic_logs', exchange_type='topic') result = channel.queue_declare(exclusive=True) queue_name = result.method.queue bind_keys=["old.*","old.#"] for bind_key in bind_keys: channel.queue_bind(exchange='topic_logs', queue=queue_name, routing_key=bind_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()
基于RabbitMQ的RPC
Callback queue 回调队列
一个客户端向服务器发送请求,服务器端处理请求后,将其处理结果保存在一个存储体中。而客户端为了获得处理结果,那么客户在向服务器发送请求时,同时发送一个回调队列地址reply_to
。
Correlation id 关联标识
一个客户端可能会发送多个请求给服务器,当服务器处理完后,客户端无法辨别在回调队列中的响应具体和那个请求时对应的。为了处理这种情况,客户端在发送每个请求时,同时会附带一个独有correlation_id
属性,这样客户端在回调队列中根据correlation_id
字段的值就可以分辨此响应属于哪个请求。
客户端发送请求:某个应用将请求信息交给客户端,然后客户端发送RPC请求,在发送RPC请求到RPC请求队列时,客户端至少发送带有reply_to以及correlation_id两个属性的信息 服务器端工作流: 等待接受客户端发来RPC请求,当请求出现的时候,服务器从RPC请求队列中取出请求,然后处理后,将响应发送到reply_to指定的回调队列中 客户端接受处理结果: 客户端等待回调队列中出现响应,当响应出现时,它会根据响应中correlation_id字段的值,将其返回给对应的应用
服务器端
#!/usr/bin/env python import pika # 建立连接,服务器地址为localhost,可指定ip地址 connection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost')) # 建立会话 channel = connection.channel() # 声明RPC请求队列 channel.queue_declare(queue='rpc_queue') # 数据处理方法 def fib(n): if n == 0: return 0 elif n == 1: return 1 else: return fib(n-1) + fib(n-2) # 对RPC请求队列中的请求进行处理 def on_request(ch, method, props, body): n = int(body) print(" [.] fib(%s)" % n) # 调用数据处理方法 response = fib(n) # 将处理结果(响应)发送到回调队列 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) # 负载均衡,同一时刻发送给该服务器的请求不超过一个 channel.basic_qos(prefetch_count=1) channel.basic_consume(on_request, queue='rpc_queue') print(" [x] Awaiting RPC requests") channel.start_consuming()
客户端
#!/usr/bin/env python import pika import uuid class FibonacciRpcClient(object): def __init__(self): ”“” 客户端启动时,创建回调队列,会开启会话用于发送RPC请求以及接受响应 “”“ # 建立连接,指定服务器的ip地址 self.connection = pika.BlockingConnection(pika.ConnectionParameters( host='localhost')) # 建立一个会话,每个channel代表一个会话任务 self.channel = self.connection.channel() # 声明回调队列,再次声明的原因是,服务器和客户端可能先后开启,该声明是幂等的,多次声明,但只生效一次 result = self.channel.queue_declare(exclusive=True) # 将次队列指定为当前客户端的回调队列 self.callback_queue = result.method.queue # 客户端订阅回调队列,当回调队列中有响应时,调用`on_response`方法对响应进行处理; self.channel.basic_consume(self.on_response, no_ack=True, queue=self.callback_queue) # 对回调队列中的响应进行处理的函数 def on_response(self, ch, method, props, body): if self.corr_id == props.correlation_id: self.response = body # 发出RPC请求 def call(self, n): # 初始化 response self.response = None #生成correlation_id self.corr_id = str(uuid.uuid4()) # 发送RPC请求内容到RPC请求队列`rpc_queue`,同时发送的还有`reply_to`和`correlation_id` 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) # 建立客户端 fibonacci_rpc = FibonacciRpcClient() # 发送RPC请求 print(" [x] Requesting fib(30)") response = fibonacci_rpc.call(30) print(" [.] Got %r" % response)