你好我试着用rabbitmq在python中编写代码。我有一个队列,我发送消息,但我必须检查消费者是否已在最后5秒发送消息,如果不是,我应该终止该过程。我试图在互联网上搜索这样的功能,但是没有相关的答案,你能告诉我一些人吗?
答案 0 :(得分:1)
RabbitMQ包含检测无响应对等体/失败消息的心跳
使用心跳检测死TCP连接
在某些类型的网络故障中,丢包可能意味着中断 TCP连接需要相当长的时间(约11分钟 Linux上的默认配置,例如) 操作系统。 AMQP 0-9-1提供心跳功能以确保这一点 应用程序层及时发现有关连接中断的信息 (也是完全没有反应的同龄人)。心跳也有所保护 针对可能终止“空闲”TCP的某些网络设备 连接。
使用Java Client启用Hearbeats:
ConnectionFactory cf = new ConnectionFactory();
// set the heartbeat timeout to 5 seconds
cf.setRequestedHeartbeat(5);
与.NET Client类似:
var cf = new ConnectionFactory();
// set the heartbeat timeout to 5 seconds
cf.RequestedHeartbeat = 5;
希望这有帮助。
(在rabbitmq文档中还有更多关于dead-letter exchanges的内容,关于nack和ack /(neg / pos)传递/确认on this page,但配置Heartbeats应该可以解决问题。)
编辑:对不起,文档中还有一个python remote procedure callback example!它需要'pika' ..错过了!服务器代码示例:
#!/usr/bin/env python
import pika
connection = pika.BlockingConnection(pika.ConnectionParameters(host='localhost'))
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(on_request, queue='rpc_queue')
print(" [x] Awaiting RPC requests")
channel.start_consuming()
客户端代码示例:
#!/usr/bin/env python
import pika
import uuid
class FibonacciRpcClient(object):
def __init__(self):
self.connection = pika.BlockingConnection(pika.ConnectionParameters(host='localhost'))
self.channel = self.connection.channel()
result = self.channel.queue_declare(exclusive=True)
self.callback_queue = result.method.queue
self.channel.basic_consume(self.on_response, no_ack=True,
queue=self.callback_queue)
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(30)
print(" [.] Got %r" % response)