Although the documentation claims that CDH 6.3 supports JDK 11.0.3 or higher (https://docs.cloudera.com/documentation/enterprise/6/release-notes/topics/rg_java_requirements.html)... there seems to be a problem with the version numbering scheme used in JDK 11 (https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/Runtime.Version.html) not being supported by older versions of jetty that are still being used.

HDFS Datanodes fail to start:

java.lang.ExceptionInInitializerError at org.eclipse.jetty.webapp.WebInfConfiguration.findAndFilterContainerPaths(WebInfConfiguration.java:185) at org.eclipse.jetty.webapp.WebInfConfiguration.preConfigure(WebInfConfiguration.java:155) at org.eclipse.jetty.webapp.WebAppContext.preConfigure(WebAppContext.java:485) at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:521) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:131) at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:113) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:131) at org.eclipse.jetty.server.Server.start(Server.java:427) at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:105) at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61) at org.eclipse.jetty.server.Server.doStart(Server.java:394) at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68) at org.apache.hadoop.http.HttpServer2.start(HttpServer2.java:1144) at org.apache.hadoop.hdfs.server.datanode.web.DatanodeHttpServer.<init>(DatanodeHttpServer.java:140) at org.apache.hadoop.hdfs.server.datanode.DataNode.startInfoServer(DataNode.java:957) at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:1415) at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:500) at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:2822) at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:2725) at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:2772) at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:2916) at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:2940) Caused by: java.lang.IllegalArgumentException: Invalid Java version 11.0.9.1 at org.eclipse.jetty.util.JavaVersion.parseJDK9(JavaVersion.java:71) at org.eclipse.jetty.util.JavaVersion.parse(JavaVersion.java:49) at org.eclipse.jetty.util.JavaVersion.<clinit>(JavaVersion.java:43) ... 25 more