Spring集成-队列/轮询似乎耗尽线程池而无需任何操作

Question

我有一个Spring集成应用程序，附加到AMQP经纪人。

我想从amqp队列接收消息，并更新数据库记录。

为了提高性能，我有一组工作人员允许同时进行多个更新。

我有以下配置：

<int-amqp:inbound-channel-adapter queue-names="pricehub.fixtures.priceUpdates.queue" 
                            channel="pricehub.fixtures.priceUpdates.channel"
                            message-converter="jsonMessageConverter"/>

<int:channel id="pricehub.fixtures.priceUpdates.channel">
    <int:queue  />
</int:channel>

<int:service-activator ref="updatePriceAction" 
     method="updatePrices" 
     input-channel="pricehub.instruments.priceUpdates.channel">
    <int:poller fixed-delay="50" time-unit="MILLISECONDS" task-executor="taskExecutor" />
</int:service-activator>

<task:executor id="taskExecutor" pool-size="5-50" keep-alive="120" queue-capacity="500"/>

如果我开始运行此程序，而AMQP通道上没有任何入站消息要处理，则我很快会看到thredpool耗尽，并开始拒绝。

这是日志：

[Thu Apr 2013 23:41:51.153] DEBUG [] (org.springframework.amqp.rabbit.listener.BlockingQueueConsumer:185) - Retrieving delivery for Consumer: tag=[amq.ctag-w4qPp60jVEQOIEovR4cERv], channel=Cached Rabbit Channel: AMQChannel(amqp://guest@127.0.0.1:5672/,1), acknowledgeMode=AUTO local queue size=0
[Thu Apr 2013 23:41:51.160] DEBUG [] (org.springframework.amqp.rabbit.listener.BlockingQueueConsumer:185) - Retrieving delivery for Consumer: tag=[amq.ctag-Q3Lq4R9g9E8WBNVLYzaFmq], channel=Cached Rabbit Channel: AMQChannel(amqp://guest@127.0.0.1:5672/,2), acknowledgeMode=AUTO local queue size=0
[Thu Apr 2013 23:41:51.166] DEBUG [] (org.springframework.amqp.rabbit.listener.BlockingQueueConsumer:185) - Retrieving delivery for Consumer: tag=[amq.ctag-w8bg7ltEV2mot8QXDPCmfK], channel=Cached Rabbit Channel: AMQChannel(amqp://guest@127.0.0.1:5672/,3), acknowledgeMode=AUTO local queue size=0
[Thu Apr 2013 23:41:51.170] DEBUG [] (org.springframework.amqp.rabbit.listener.BlockingQueueConsumer:185) - Retrieving delivery for Consumer: tag=[amq.ctag-A-0KdqhFjpc-Hvjmv7aZAc], channel=Cached Rabbit Channel: AMQChannel(amqp://guest@127.0.0.1:5672/,4), acknowledgeMode=AUTO local queue size=0
[Thu Apr 2013 23:41:51.180] DEBUG [] (org.springframework.integration.endpoint.PollingConsumer:71) - Received no Message during the poll, returning 'false'
[Thu Apr 2013 23:41:51.180] DEBUG [] (org.springframework.integration.endpoint.PollingConsumer:71) - Received no Message during the poll, returning 'false'
[Thu Apr 2013 23:41:51.199] DEBUG [] (org.springframework.integration.endpoint.PollingConsumer:71) - Received no Message during the poll, returning 'false'
[Thu Apr 2013 23:41:51.200] DEBUG [] (org.springframework.integration.endpoint.PollingConsumer:71) - Received no Message during the poll, returning 'false'
[Thu Apr 2013 23:41:51.220] DEBUG [] (org.springframework.integration.endpoint.PollingConsumer:71) - Received no Message during the poll, returning 'false'

很快，线程池开始拒绝执行：

[Thu Apr 2013 23:47:15.363] ERROR [] (org.springframework.integration.handler.LoggingHandler:126) - org.springframework.core.task.TaskRejectedException: Executor [java.util.concurrent.ThreadPoolExecutor@6ff3cb0e] did not accept task: org.springframework.integration.util.ErrorHandlingTaskExecutor$1@78615c8b
    at org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor.execute(ThreadPoolTaskExecutor.java:244)
    at org.springframework.integration.util.ErrorHandlingTaskExecutor.execute(ErrorHandlingTaskExecutor.java:49)
    at org.springframework.integration.endpoint.AbstractPollingEndpoint$Poller.run(AbstractPollingEndpoint.java:231)
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:53)
    at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:81)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:206)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:680)
Caused by: java.util.concurrent.RejectedExecutionException
    at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:1768)
    at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:767)
    at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:658)
    at org.springframework.sched

uling.concurrent.ThreadPoolTask​​Executor.execute（ThreadPoolTask​​Executor.java:241）…还有12个

我怀疑罪魁祸首就在这里：BlockingQueueConsumer-表示每次对消息的轮询都会阻塞线程，直到消息到达为止…导致线程池迅速耗尽。

什么是正确的配置方式？

Answer 1

QueueChannel为什么不简单地增加concurrent-consumers入站适配器上的属性，而不是使用and轮询器？

    <xsd:attribute name="concurrent-consumers" type="xsd:string">
        <xsd:annotation>
            <xsd:documentation>
Specify the number of concurrent consumers to create. Default is 1.
Raising the number of concurrent consumers is recommended in order to scale the consumption of messages coming in
from a queue. However, note that any ordering guarantees are lost once multiple consumers are registered. In
general, stick with 1 consumer for low-volume queues.
            </xsd:documentation>
        </xsd:annotation>
    </xsd:attribute>

并且，删除<queue/>和<poller/>。

另外，我总是建议在日志中包含线程名称（%t对于log4J）；它使调试线程问题变得更加容易。

编辑：

使用轮询器时，线程不足的原因是轮询器的默认receive- timeout值为1秒。您每50ms调度一个线程，但是每个线程等待QueueChannel1秒。最终，您的任务队列已满。

为避免这种情况，如果希望继续使用此技术，只需将设置receive- timeout为0on，<poller/>但是在适配器中使用更高的并发效率更高，因为没有轮询或切换到另一个线程。