Reply message received but the receiving thread has exited due to a timeout

Question

This is a follow-up to this question:

Spring Integration Aggregator failing - "No reply received within timeout" message being displayed

While continuing to test my POC on WebSphere 8.5, the issue resurfaced where this error came from nowhere:

GenericMessag W org.springframework.messaging.core.GenericMessagingTemplate$‌​TemporaryReplyChanne‌​l send Reply message received but the receiving thread has exited due to a timeout:ErrorMessage [payload=org.springframework.messaging.MessageHandlingExcept‌​ion: error occurred in message handler [productAggregator.generateAggregatedResponse.aggregator.han‌​dler]; nested exception is java.lang.NullPointerException, headers={id=d0b52beb-e9bd-0ba2-6062-6ee83b847c4a, timestamp=1504755248824}].

I see that this is happening once the Aggregator has started but what is not clear is the nested exception "java.lang.NullPointerException" and what the null value here is that is leading to a timeout. And the other question is if the Aggregator has a default time out value to "wait" on its input channel after which it stops waiting, leading to a time out.

Any pointers will be greatly appreciated while I continue to debug.

Sincerely, Bharath

Answer 1

Put a big try/catch around your aggregator code to find out where the NPE is being thrown.

The message is generated by some up-stream messaging gateway (or direct use of a MessagingTemplate ) where the calling thread has already timed out and this async exception is received by the template.