Prometheus JMX exporter jar, stops starting the wildfly server. ---------------------------------------------------------------- Key: WFCORE-5053 URL: https://issues.redhat.com/browse/WFCORE-5053 Project: WildFly Core Issue Type: Bug Components: Logging Reporter: Rakesh Kumar Shah Assignee: James Perkins Priority: Major Fix For: 13.0.0.Beta1 Trying to integrate the Prometheus JMX exporter with wildfly.  After spending lot of time and work around it, wildfly is not starting.  It throws following exception.  {code} java.lang.ClassNotFoundException: org.jboss.logmanager.LogManager at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) at java.logging/java.util.logging.LogManager$1.run(LogManager.java:239) at java.logging/java.util.logging.LogManager$1.run(LogManager.java:223) at java.base/java.security.AccessController.doPrivileged(Native Method) at java.logging/java.util.logging.LogManager.<clinit>(LogManager.java:223) at java.logging/java.util.logging.Logger.demandLogger(Logger.java:648) at java.logging/java.util.logging.Logger.getLogger(Logger.java:717) at java.logging/java.util.logging.Logger.getLogger(Logger.java:701) at io.prometheus.jmx.shaded.io.prometheus.jmx.JmxCollector.<clinit>(JmxCollector.java:39) at io.prometheus.jmx.shaded.io.prometheus.jmx.JavaAgent.premain(JavaAgent.java:29) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:513) at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:525) WARNING: Failed to load the specified log manager class org.jboss.logmanager.LogManager Exception in thread "main" java.lang.NoClassDefFoundError: org/jboss/logmanager/Level at java.base/java.lang.Class.forName0(Native Method) at java.base/java.lang.Class.forName(Class.java:398) at org.jboss.modules.Module.run(Module.java:340) at org.jboss.modules.Module.run(Module.java:320) at org.jboss.modules.Main.main(Main.java:617) Caused by: java.lang.ClassNotFoundException: org.jboss.logmanager.Level at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) at org.jboss.modules.JDKSpecific.getSystemClass(JDKSpecific.java:183) at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:395) at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:116) {code}