ArrayIndexOutOfBoundsException in FD_SOCK ----------------------------------------- Key: JGRP-2290 URL: https://issues.jboss.org/browse/JGRP-2290 Project: JGroups Issue Type: Bug Affects Versions: 4.0.13 Reporter: Dan Berindei Assignee: Bela Ban Fix For: 4.0.15 {noformat} 23:30:00.046 [INFO] Running org.infinispan.test.hibernate.cache.commons.entity.EntityRegionAccessStrategyTest Exception in thread "FD_SOCK pinger-10,EntityRegionAccessStrategyTest-NodeJ-23765" java.lang.ArrayIndexOutOfBoundsException: 0 at java.util.concurrent.CopyOnWriteArrayList.get(CopyOnWriteArrayList.java:388) at java.util.concurrent.CopyOnWriteArrayList.get(CopyOnWriteArrayList.java:397) at org.jgroups.util.Util.pickNext(Util.java:2656) at org.jgroups.protocols.FD_SOCK.determinePingDest(FD_SOCK.java:762) at org.jgroups.protocols.FD_SOCK.run(FD_SOCK.java:407) at java.lang.Thread.run(Thread.java:748) {noformat} The {{pingable_mbrs}} and {{suspected_mbrs}} collections are not read that often, so I suggest using regular synchronization instead of {{CopyOnWriteList}}.