[UIMA-1797] UIMA AS processParentLast logic is not working correctly

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3AS
• Fix Version/s: 2.3.1AS
• Component/s: Async Scaleout
• Assignee: Jaroslaw Cwiklik
• Reporter: Jaroslaw Cwiklik
• Created: 01/Jun/10 19:31
• Updated: 15/Sep/10 18:51
• Resolved: 02/Jun/10 13:42

Description

UIMA AS aggregate fails with NPE when using multiple CMs configured with processParentLast=true. The aggregate throws this:
java.lang.NullPointerException
at org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.forceToDropTheCas(AggregateAnalysisEngineController_impl.java:1822)
at org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.finalStep(AggregateAnalysisEngineController_impl.java:1624)
at org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.finalStep(AggregateAnalysisEngineController_impl.java:1714)
at org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.executeFlowStep(AggregateAnalysisEngineController_impl.java:2175)
at org.apache.uima.aae.controller.AggregateAnalysisEngineController_impl.process(AggregateAnalysisEngineController_impl.java:1207)
at org.apache.uima.aae.handler.HandlerBase.invokeProcess(HandlerBase.java:118)
at org.apache.uima.aae.handler.input.ProcessResponseHandler.cancelTimerAndProcess(ProcessResponseHandler.java:108)
at org.apache.uima.aae.handler.input.ProcessResponseHandler.handleProcessResponseWithCASReference(ProcessResponseHandler.java:383)
at org.apache.uima.aae.handler.input.ProcessResponseHandler.handle(ProcessResponseHandler.java:647)
at org.apache.uima.aae.handler.HandlerBase.delegate(HandlerBase.java:149)
at org.apache.uima.aae.handler.input.ProcessRequestHandler_impl.handle(ProcessRequestHandler_impl.java:989)
at org.apache.uima.aae.spi.transport.vm.UimaVmMessageListener.onMessage(UimaVmMessageListener.java:107)
at org.apache.uima.aae.spi.transport.vm.UimaVmMessageDispatcher$1.run(UimaVmMessageDispatcher.java:70)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)

It does not matter if CMs are colocated or remote. If there is more than one CM with processParentLast=true, the code fails as above. The failure seems to occur while processing parent of the last child CAS.