ConcurrentModificationException in StateRequestCommand ------------------------------------------------------- Key: ISPN-2736 URL: https://issues.jboss.org/browse/ISPN-2736 Project: Infinispan Issue Type: Bug Components: State transfer Affects Versions: 5.2.0.CR2 Reporter: Radim Vansa Assignee: Adrian Nistor Priority: Critical Fix For: 5.2.0.CR3 I have tried async replication scenario with async marshalling (optimistic transactions) and this has occurred: {code} 04:34:15,182 ERROR [org.infinispan.remoting.rpc.RpcManagerImpl] (OOB-77,edg-perf11-48420) ISPN000073: Unexpected error while replicating java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793) at java.util.HashMap$KeyIterator.next(HashMap.java:828) at org.infinispan.statetransfer.StateProviderImpl.collectTransactionsToTransfer(StateProviderImpl.java:239) at org.infinispan.statetransfer.StateProviderImpl.getTransactionsForSegments(StateProviderImpl.java:200) at org.infinispan.statetransfer.StateRequestCommand.perform(StateRequestCommand.java:88) at org.infinispan.remoting.InboundInvocationHandlerImpl.handleInternal(InboundInvocationHandlerImpl.java:101) at org.infinispan.remoting.InboundInvocationHandlerImpl.handleWithWaitForBlocks(InboundInvocationHandlerImpl.java:122) at org.infinispan.remoting.InboundInvocationHandlerImpl.handle(InboundInvocationHandlerImpl.java:86) at org.infinispan.remoting.transport.jgroups.CommandAwareRpcDispatcher.executeCommandFromLocalCluster(CommandAwareRpcDispatcher.java:245) at org.infinispan.remoting.transport.jgroups.CommandAwareRpcDispatcher.handle(CommandAwareRpcDispatcher.java:218) at org.jgroups.blocks.RequestCorrelator.handleRequest(RequestCorrelator.java:484) at org.jgroups.blocks.RequestCorrelator.receiveMessage(RequestCorrelator.java:391) at org.jgroups.blocks.RequestCorrelator.receive(RequestCorrelator.java:249) at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.up(MessageDispatcher.java:598) at org.jgroups.JChannel.up(JChannel.java:707) {code} Seems that StateRequestCommand is iterating through all transactions' locked keys but the collections of these locked keys can be modified by interfering prepare/commit.