IllegalThreadStateException after idle jmx connection ----------------------------------------------------- Key: REMJMX-166 URL: https://issues.redhat.com/browse/REMJMX-166 Project: Remoting JMX Issue Type: Bug Components: Connection Affects Versions: 3.0.2.Final, 3.0.3.Final Environment: org.jboss.remotingjmx:remoting-jmx:3.0.3.Final + java8 Reporter: Märt Bakhoff Assignee: Darran Lofthouse Priority: Blocker Start wildfly-17.0.1/bin/standalone.sh, then run this code snippet: {noformat} JMXServiceURL url = new JMXServiceURL("service:jmx:remote+http://127.0.0.1:9990"); try (JMXConnector connector = new RemotingConnectorProvider().newJMXConnector(url, Collections.emptyMap())) { connector.connect(); MBeanServerConnection beanServer = connector.getMBeanServerConnection(); RuntimeMXBean bean = ManagementFactory.newPlatformMXBeanProxy(beanServer, ManagementFactory.RUNTIME_MXBEAN_NAME, RuntimeMXBean.class); Thread.sleep(70_000); System.out.println("uptime: " + bean.getUptime()); } {noformat} The following exception is always thrown: {noformat} Exception in thread "XNIO-1 task-12" java.lang.IllegalThreadStateException at java.lang.ThreadGroup.addUnstarted(ThreadGroup.java:867) at java.lang.Thread.init(Thread.java:405) at java.lang.Thread.init(Thread.java:349) at java.lang.Thread.<init>(Thread.java:599) at org.jboss.remotingjmx.protocol.v2.ClientExecutorManager$1.newThread(ClientExecutorManager.java:56) at java.util.concurrent.ThreadPoolExecutor$Worker.<init>(ThreadPoolExecutor.java:619) at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:932) at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1378) at org.jboss.remotingjmx.protocol.v2.ClientExecutorManager.execute(ClientExecutorManager.java:64) at org.jboss.remotingjmx.protocol.v2.ClientCommon$MessageReceiver.handleMessage(ClientCommon.java:118) at org.jboss.remoting3.remote.RemoteConnectionChannel.lambda$handleMessageData$3(RemoteConnectionChannel.java:430) at org.jboss.remoting3.EndpointImpl$TrackingExecutor.lambda$execute$0(EndpointImpl.java:926) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) {noformat} The cause is in org.jboss.remotingjmx.protocol.v2.ClientExecutorManager.<init>. It creates a thread pool with Executors.newCachedThreadPool that has the default keepAliveTime of 60s. The thread factory is using a daemon thread group REMOTING_JMX that will self-destruct when the cached thread is terminated. The same code works when using older org.jboss.remotingjmx:remoting-jmx:3.0.1.Final. The regression is likely caused by commit https://github.com/jbossas/remoting-jmx/commit/2d6ae6c26da43304b752fc48f1...