Apache Camel Infinite Loop on error

Question

I'm having a problem with an infinite loop in Apache Camel (2.15.2). The route shown below works fine under normal conditions. However, in some rare cases, an infinite loop is created which consumes all CPU. I'm not sure what causes this, but I have a feeling it's related to when the remote application producing messages on the route is shutting down.

Code to configure the route (using RouteBuilder):

@Override
public void configure() throws Exception {
    errorHandler(deadLetterChannel(
        "file:messages/myRoute?fileName=${date:now:yyyyMMdd-HHmm-ssSSS}.xml")
        .useOriginalMessage()
        .maximumRedeliveries(10)
        .delayPattern("1:5000");
    onException(java.net.ConnectException.class).handled(true);

    fromF("myEndpoint")
        .routeId("myRoute")
        .bean(messageHandler, "process");
}

The bean handling the message:

public void process(final String message) {
    final MyMessage message = (MyMessage) marshaller.getXStream().fromXML(message);
    ...some processing...
    producer.sendBody("anotherEndpoint", marshaller.getXStream().toXML(message));
}

I've made several thread dumps and they all show stuff similar to this:

at com.thoughtworks.xstream.core.DefaultConverterLookup.lookupConverterForType(DefaultConverterLookup.java:56)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:56)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1206)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1190)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1061)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1052)
at com.example.message.MessageHandler.process(MessageHandler.java:58)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.camel.component.bean.MethodInfo.invoke(MethodInfo.java:408)
at org.apache.camel.component.bean.MethodInfo$1.doProceed(MethodInfo.java:279)
at org.apache.camel.component.bean.MethodInfo$1.proceed(MethodInfo.java:252)
at org.apache.camel.component.bean.BeanProcessor.process(BeanProcessor.java:171)
at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)
at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:448)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:191)
at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:191)
at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:109)
at org.apache.camel.processor.DelegateAsyncProcessor.process(DelegateAsyncProcessor.java:87)
at org.apache.camel.component.jms.EndpointMessageListener.onMessage(EndpointMessageListener.java:103)
at org.springframework.jms.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:746)
at org.springframework.jms.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:684)
at org.springframework.jms.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:651)
at org.springframework.jms.listener.AbstractPollingMessageListenerContainer.doReceiveAndExecute(AbstractPollingMessageListenerContainer.java:315)
at org.springframework.jms.listener.AbstractPollingMessageListenerContainer.receiveAndExecute(AbstractPollingMessageListenerContainer.java:253)
at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.invokeListener(DefaultMessageListenerContainer.java:1164)
at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.executeOngoingLoop(DefaultMessageListenerContainer.java:1156)
at org.springframework.jms.listener.DefaultMessageListenerContainer$AsyncMessageListenerInvoker.run(DefaultMessageListenerContainer.java:1053)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)

Perhaps my errorHandler and/or onException are incorrect? Thank you!

Answer 1

The infinite loop may be related to a concurrency issue in the underlying x-stream library. See https://github.com/x-stream/xstream/issues/2 and the related issues.