NPE in MapReduceTask reduce phase --------------------------------- Key: ISPN-3321 URL: https://issues.jboss.org/browse/ISPN-3321 Project: Infinispan Issue Type: Bug Components: Distributed Execution and Map/Reduce Affects Versions: 5.3.0.Final Reporter: Alan Field Assignee: Dan Berindei Priority: Critical Labels: jdg62GAblocker Fix For: 6.0.0.CR1 During the execution of a MapReduce word count job with 6 nodes, the following NPE is thrown: 11:19:37,870 ERROR [org.infinispan.remoting.InboundInvocationHandlerImpl] (remote-thread-2) Exception executing command java.lang.NullPointerException at org.infinispan.distexec.mapreduce.MapReduceManagerImpl.reduce(MapReduceManagerImpl.java:153) at org.infinispan.commands.read.ReduceCommand.perform(ReduceCommand.java:88) at org.infinispan.remoting.InboundInvocationHandlerImpl.handleInternal(InboundInvocationHandlerImpl.java:122) at org.infinispan.remoting.InboundInvocationHandlerImpl.access$000(InboundInvocationHandlerImpl.java:68) at org.infinispan.remoting.InboundInvocationHandlerImpl$2.run(InboundInvocationHandlerImpl.java:194) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:724) The full log is here - https://jenkins.mw.lab.eng.bos.redhat.com/hudson/user/afield@REDHAT.COM/m... Looking at the code to see if I can figure out what happened.