Intermittent NPE in JGroups GMS#up on shutdown ---------------------------------------------- Key: JGRP-2231 URL: https://issues.jboss.org/browse/JGRP-2231 Project: JGroups Issue Type: Bug Affects Versions: 3.6.14, 4.0.8 Reporter: Radoslav Husar Assignee: Radoslav Husar Priority: Minor Fix For: 4.0.9 Attachments: server.log, standalone-ha.xml During mod_cluster failover due application undeploy on Solaris 10 intermittently I can see NPE \[1\]. I've seen it already several times during failover with HTTPD with mod_cluster as balancer and EAP 7.1 as workers where their communication works over SSL which is configured using elytron on EAP side. I have seen the issue on Solaris 10 sparc (two different slaves). \[1\] {noformat} 2017-10-27 12:12:07,546 ERROR [org.jgroups.protocols.pbcast.GMS] (thread-2) JGRP000027: failed passing message up: java.lang.NullPointerException at org.jgroups.protocols.pbcast.GMS.up(GMS.java:895) at org.jgroups.stack.Protocol.up(Protocol.java:418) at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:294) at org.jgroups.protocols.UNICAST3.up(UNICAST3.java:487) at org.jgroups.protocols.pbcast.NAKACK2.deliverBatch(NAKACK2.java:989) at org.jgroups.protocols.pbcast.NAKACK2.removeAndPassUp(NAKACK2.java:919) at org.jgroups.protocols.pbcast.NAKACK2.handleMessage(NAKACK2.java:851) at org.jgroups.protocols.pbcast.NAKACK2.up(NAKACK2.java:611) at org.jgroups.protocols.VERIFY_SUSPECT.up(VERIFY_SUSPECT.java:155) at org.jgroups.protocols.FD_ALL.up(FD_ALL.java:200) at org.jgroups.protocols.FD_SOCK.up(FD_SOCK.java:325) at org.jgroups.protocols.MERGE3.up(MERGE3.java:292) at org.jgroups.protocols.Discovery.up(Discovery.java:296) at org.jgroups.protocols.TP.passMessageUp(TP.java:1657) at org.jgroups.protocols.TP$SingleMessageHandler.run(TP.java:1872) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.jboss.as.clustering.jgroups.ClassLoaderThreadFactory.lambda$newThread$0(ClassLoaderThreadFactory.java:52) at java.lang.Thread.run(Thread.java:748) {noformat}