python rabbitmq实现rpc Python RabbitMQ消息队列实现rpc
dugufei 人气:0上个项目中用到了ActiveMQ,只是简单应用,安装完成后直接是用就可以了。由于新项目中一些硬件的限制,需要把消息队列换成RabbitMQ。
RabbitMQ中的几种模式和机制比ActiveMQ多多了,根据业务需要,使用RPC实现功能,其中踩过的一些坑,有必要记录一下了。
上代码,目录结构分为 c_server、c_client、c_hanlder:
c_server:
#!/usr/bin/env python # -*- coding:utf-8 -*- import pika import time import json import io import yaml s_exchange = input("请输入交换机名称->>").decode('utf-8').strip() s_queue = input("输入消息队列名称->>").decode('utf-8').strip() credentials = pika.PlainCredentials('system', 'manager') connection = pika.BlockingConnection(pika.ConnectionParameters(host='XXX.XXX.XXX.XXX',credentials=credentials)) # 定义 channel = connection.channel() channel.exchange_declare(exchange=s_exchange, exchange_type='direct') channel.queue_declare(queue=s_queue, exclusive=True) channel.queue_bind(queue=s_queue, exchange=s_exchange) def s_manage(content): # 解决unicode转码问题 json.JSONDecoder().decode(content) str_content = yaml.safe_load(json.loads(content,encoding='utf-8')) str_res = { "errorid": 0, "resp": str_content['cmd'], "errorcont": "成功" } return json.dumps(str_res) def on_request(ch, method, props, body): response = s_manage(body) ch.basic_publish(exchange='', routing_key=props.reply_to, properties=pika.BasicProperties(correlation_id = \ props.correlation_id), body=response) ch.basic_ack(delivery_tag = method.delivery_tag) channel.basic_qos(prefetch_count=1) channel.basic_consume(on_request, queue=s_queue) print(" [x] Awaiting RPC requests") channel.start_consuming()
c_client:
#!/usr/bin/env python # -*- coding:utf-8 -*- import pika import uuid import json import io class RpcClient(object): def __init__(self): self.credentials = pika.PlainCredentials('guest', 'guest') self.connection = pika.BlockingConnection(pika.ConnectionParameters(host='XXX.XXX.XXX.XXX', credentials=self.credentials)) self.channel = self.connection.channel() def on_response(self, ch, method, props, body): if self.callback_id == props.correlation_id: self.response = body ch.basic_ack(delivery_tag=method.delivery_tag) def get_response(self, callback_queue, callback_id): '''取队列里的值,获取callback_queued的执行结果''' self.callback_id = callback_id self.response = None self.channel.queue_declare('q_manager', durable=True) self.channel.basic_consume(self.on_response, # 只要收到消息就执行on_response queue=callback_queue) while self.response is None: self.connection.process_data_events() # 非阻塞版的start_consuming return self.response def call(self, queue_name, command, exchange,rout_key): # 命令下发 '''队列里发送数据''' # result = self.channel.queue_declare(exclusive=False) #exclusive=False 必须这样写 self.callback_queue = 'q_manager' # result.method.queue self.corr_id = str(uuid.uuid4()) self.channel.basic_publish(exchange=exchange, routing_key=queue_name, properties=pika.BasicProperties( reply_to=self.callback_queue, # 发送返回信息的队列name correlation_id=self.corr_id, # 发送uuid 相当于验证码 ), body=command) return self.callback_queue,self.corr_id client
c_handler:
#!/usr/bin/env python # -*- coding:utf-8 -*- from c_client import * import random, time import threading import json import sys class Handler(object): def __init__(self): self.information = {} # 后台进程信息 def check_all(self, *args): '''查看所有信息''' time.sleep(2) print('获取消息') for key in self.information: print("cid【%s】\t 队列【%s】\t 命令【%s】"%(key, self.information[key][0], self.information[key][1])) def check_task(self, cmd): '''查看task_id执行结果''' time.sleep(2) try: task_id = int(cmd) print(task_id) callback_queue= self.information[task_id][2] callback_id= self.information[task_id][3] client = RpcClient() response = client.get_response(callback_queue, callback_id) print(response) # print(response.decode()) del self.information[task_id] except KeyError as e : print("error: [%s]" % e) except IndexError as e: print("error: [%s]" % e) def run(self, user_cmd, host, exchange='', rout_key='',que=''): try: time.sleep(2) command = user_cmd task_id = random.randint(10000, 99999) client = RpcClient() response = client.call(queue_name=host, command=command,exchange=exchange,rout_key=que) self.information[task_id] = [host, command, response[0], response[1]] except IndexError as e: print("[error]:%s"%e) def reflect(self, str,cmd,host,exchange,que): '''反射''' if hasattr(self, str): getattr(self, str)(cmd,host,exchange,que) def start(self, m,cmd, host, exchange,que): while True: user_resp = input("输入处理消息内容ID->>").decode('utf-8').strip() self.check_task(user_resp) str = m print(self.information) t1 = threading.Thread(target=self.reflect, args=(str,cmd,host,exchange,que)) #多线程 t1.start() s_exchange = input("请输入交换机名称->>").decode('utf-8').strip() s_queue = input("输入消息队列名称->>").decode('utf-8').strip() d_cmd_state =input("输入json命令->>").decode('utf-8').strip() s_cmd = json.dumps(d_cmd_state) handler = Handler() handler.start('run',s_cmd, s_queue, s_exchange, s_queue) handler
注意要点:1、c_client 发布消息到rabbitmq 需要携带 服务器返回的队列名称,及corr_id
2、c_handler 做了处理,每次发送的内容都会放到task列表中,直到显示ID号,就可以查询返回的内容,调用如下:
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