IllegalArgumentException: A metric with name classloader.currentLoadedClass.count already exists ------------------------------------------------------------------------------------------------ Key: WFLY-11731 URL: https://issues.redhat.com/browse/WFLY-11731 Project: WildFly Issue Type: Bug Components: MP Metrics Reporter: Brian Stansberry Assignee: Jason Lee Priority: Major CI failure due to $subject -- ConstantRoleMapperTestCase in https://ci.wildfly.org/viewLog.html?buildId=139312&buildTypeId=WFPR&a... {code} &amp#27;[0m&amp#27;[31m11:45:07,066 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-6) MSC000001: Failed to start service org.wildlfy.extension.microprofile.metrics.wildfly-registrar: org.jboss.msc.service.StartException in service org.wildlfy.extension.microprofile.metrics.wildfly-registrar: Failed to start service at org.jboss.msc.service.ServiceControllerImpl$StartTask.execute(ServiceControllerImpl.java:1730) at org.jboss.msc.service.ServiceControllerImpl$ControllerTask.run(ServiceControllerImpl.java:1558) at org.jboss.threads.ContextClassLoaderSavingRunnable.run(ContextClassLoaderSavingRunnable.java:35) at org.jboss.threads.EnhancedQueueExecutor.safeRun(EnhancedQueueExecutor.java:1982) at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.doRunTask(EnhancedQueueExecutor.java:1486) at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1377) at java.lang.Thread.run(Thread.java:748) Caused by: java.lang.IllegalArgumentException: A metric with name classloader.currentLoadedClass.count already exists at io.smallrye.metrics.MetricsRegistryImpl.register(MetricsRegistryImpl.java:113) at io.smallrye.metrics.setup.JmxRegistrar.register(JmxRegistrar.java:54) at io.smallrye.metrics.setup.JmxRegistrar.register(JmxRegistrar.java:38) at io.smallrye.metrics.setup.JmxRegistrar.init(JmxRegistrar.java:30) at org.wildfly.extension.microprofile.metrics.MetricsRegistrationService.start(MetricsRegistrationService.java:91) at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1738) at org.jboss.msc.service.ServiceControllerImpl$StartTask.execute(ServiceControllerImpl.java:1700) ... 6 more {code} I have a feeling this has already been reported but simple searching didn't find it.