[CAMEL-18821] camel-core - Thread hangs on transacted routes after aggregation and multiplex (possibly more)

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Cannot Reproduce
• Fix Version/s: 4.7.0
• Component/s: camel-core

Environment

Quarkus 3.18.3, 3.18.4, 3.19.0 in TomEE 8.0.13 on JDK 17 (Termium).

• Estimated Complexity: Unknown
• Regression: Regression
• Assignee: Claus Ibsen
• Reporter: Christian Kalkhoff
• Created: 15/Dec/22 16:07
• Updated: 02/Jul/24 07:10
• Resolved: 02/Jul/24 07:10

Description

When an aggregator runs in the same thread as the transacted route (Using org.apache.camel.util.concurrent.SynchronousExecutorService for executorService), the thread hangs after completion (error or not) at camel-base-engine-3.19.0-sources.jar!/org/apache/camel/impl/engine/DefaultAsyncProcessorAwaitManager.java:107

 

latch.await(); 

 

If I run latch.countDown() in a debugger, the thread continues just fine.

For the success case I found the workaround to set jtaTransactionErrorHandler()for the route containing the aggregator. Still in case of an exception thrown from the code processing the aggregated messages, the thread hangs.

See https://camel.zulipchat.com/#narrow/stream/257298-camel/topic/Deadlock.20in.20transacted.20route.2E.20is.20this.20a.20bug.3F for the discussion on this.