骆驼-DirectConsumerNotAvailableException端点上没有可用的使用者

Question

I have been searching for this issue on Google as well as here on Stackoverflow. I've seen several others report this same exception, and although I understand what the suggested solution is, I am not 100% if I am witnessing the exact same problem if you will.

Of course, here's the exception:

I have a Camel project with two routes. Here's a simplification:

<route>
  <from uri="jetty://http://0.0.0.0:8181/listener"/>
  <to uri="direct:ProcessMessage"/>
</route>

<route>
  <from uri="direct:ProcessMessage"/>
  ...
</route>

So this code snippet works fine most of the time. However, I was attempting to test the scalability of code. At what point does system start to fail?

When sending the box 100 messages per second on the listener endpoint above (using Jetty), I start seeing this in the logs:

org.apache.camel.component.direct.DirectConsumerNotAvailableException: No consumers available on endpoint: Endpoint[direct://ProcessMessage]

The solutions I have seen state this occurs because the order of the routes (ie how they're being initialized). If that is true in this situation, why does this only happen under heavier load and not all the time?

Answer 1

since it happens only under load, I bet the consumer is getting throttled. Try using jconsole to monitor the size of the queue. I'll try looking for a size limit on direct queues.