解决python3 pika之连接断开的问题

问题描述

在消费rabbitMQ队列时, 每次进入回调函数内需要进行一些比较耗时的操作;操作完成后给rabbitMQ server发送ack信号以dequeue本条消息。

问题就发生在发送ack操作时, 程序提示链接已被断开或socket error。

源码示例

#!/usr/bin#coding: utf-8import pikaimport timeUSER = 'guest'PWD = 'guest'TEST_QUEUE = 'just4test'def callback(ch, method, properties, body): print(body) time.sleep(600) ch.basic_publish('', routing_key=TEST_QUEUE, body="fortest") ch.basic_ack(delivery_tag = method.delivery_tag)def test_main(): s_conn = pika.BlockingConnection(  pika.ConnectionParameters('127.0.0.1',    credentials=pika.PlainCredentials(USER, PWD))) chan = s_conn.channel() chan.queue_declare(queue=TEST_QUEUE) chan.basic_publish('', routing_key=TEST_QUEUE, body="fortest") chan.basic_consume(callback, queue=TEST_QUEUE) chan.start_consuming()if __name__ == "__main__": test_main()

运行一段时间后， 就会报错：

[ERROR][pika.adapters.base_connection][2017-08-18 12:33:49]Error event 25, None[CRITICAL][pika.adapters.base_connection][2017-08-18 12:33:49]Tried to handle an error where no error existed[ERROR][pika.adapters.base_connection][2017-08-18 12:33:49]Fatal Socket Error: BrokenPipeError(32, 'Broken pipe')

问题排查

猜测：pika客户端没有及时发送心跳，连接被server断开

一开始修改了heartbeat_interval参数值, 示例如下:

def test_main(): s_conn = pika.BlockingConnection(  pika.ConnectionParameters('127.0.0.1',    heartbeat_interval=10,   socket_timeout=5,   credentials=pika.PlainCredentials(USER, PWD))) # ....

修改后运行依然报错，后来想想应该单线程被一直占用，pika无法发送心跳；

于是又加了个心跳线程， 示例如下：

#!/usr/bin#coding: utf-8import pikaimport timeimport loggingimport threadingUSER = 'guest'PWD = 'guest'TEST_QUEUE = 'just4test'class Heartbeat(threading.Thread): def __init__(self, connection):  super(Heartbeat, self).__init__()  self.lock = threading.Lock()  self.connection = connection  self.quitflag = False  self.stopflag = True  self.setDaemon(True) def run(self):  while not self.quitflag:   time.sleep(10)   self.lock.acquire()   if self.stopflag :    self.lock.release()    continue   try:    self.connection.process_data_events()   except Exception as ex:    logging.warn("Error format: %s"%(str(ex)))    self.lock.release()    return   self.lock.release() def startHeartbeat(self):  self.lock.acquire()  if self.quitflag==True:   self.lock.release()   return  self.stopflag=False  self.lock.release()def callback(ch, method, properties, body): logging.info("recv_body:%s" % body) time.sleep(600) ch.basic_ack(delivery_tag = method.delivery_tag)def test_main(): s_conn = pika.BlockingConnection(  pika.ConnectionParameters('127.0.0.1',    heartbeat_interval=10,   socket_timeout=5,   credentials=pika.PlainCredentials(USER, PWD))) chan = s_conn.channel() chan.queue_declare(queue=TEST_QUEUE) chan.basic_consume(callback,      queue=TEST_QUEUE) heartbeat = Heartbeat(s_conn) heartbeat.start()   #开启心跳线程 heartbeat.startHeartbeat() chan.start_consuming()if __name__ == "__main__": test_main()