Dan Berindei created JGRP-1916: ---------------------------------- Summary: ConcurrentModificationException in FD_ALL Key: JGRP-1916 URL: https://issues.jboss.org/browse/JGRP-1916 Project: JGroups Issue Type: Bug Affects Versions: 3.6.2 Reporter: Dan Berindei Assignee: Bela Ban Fix For: 3.6.3 When DEBUG logging is enabled, FD_ALL logs the set of suspected members without proper synchronization. If another thread modifies the {{suspected_mbrs}} set at the same time, it can cause a {{ConcurrentModificationException}} and the {{SUSPECT}} event will be lost. {noformat} java.util.ConcurrentModificationException at java.util.HashMap$HashIterator.nextEntry(HashMap.java:922) at java.util.HashMap$KeyIterator.next(HashMap.java:956) at java.util.AbstractCollection.toString(AbstractCollection.java:457) at java.lang.String.valueOf(String.java:2847) at java.lang.StringBuilder.append(StringBuilder.java:128) at org.jgroups.protocols.FD_ALL.suspect(FD_ALL.java:368) at org.jgroups.protocols.FD_ALL$TimeoutChecker.run(FD_ALL.java:444) at org.jgroups.util.TimeScheduler3$Task.run(TimeScheduler3.java:287) at org.jgroups.util.TimeScheduler3$RecurringTask.run(TimeScheduler3.java:321) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) {noformat} I would also suggest adding a synchronized block in {{getSuspectedMembers()}}, {{init()}} and {{stop()}}. FD_ALL2 seems to have the same problem. -- This message was sent by Atlassian JIRA (v6.3.11#6341)