HDFS-15100 error log

error log

## before (it shows authentication failure occurred)

2020-01-08 13:44:51,615 ERROR org.apache.hadoop.hdfs.server.federation.router.FederationUtil: Cannot read JMX bean Hadoop:service=NameNode,name=FSNamesystem* from server <namenode>:9871: Error while authenticating with endpoint: https://<namenode>:9871/jmx?qry=Hadoop:service=NameNode,name=FSNamesystem*

## after: (it shows why the authentication failure occurred)

2020-01-08 17:01:35,154 ERROR org.apache.hadoop.hdfs.server.federation.router.FederationUtil: Cannot read JMX bean Hadoop:service=NameNode,name=FSNamesystem* from server <namenode>:9871:
javax.net.ssl.SSLHandshakeException: Error while authenticating with endpoint: https://<namenode>:9871/jmx?qry=Hadoop:service=NameNode,name=FSNamesystem*
        at java.base/jdk.internal.reflect.GeneratedConstructorAccessor45.newInstance(Unknown Source)
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
        at org.apache.hadoop.security.authentication.client.KerberosAuthenticator.wrapExceptionWithMessage(KerberosAuthenticator.java:232)
        at org.apache.hadoop.security.authentication.client.KerberosAuthenticator.authenticate(KerberosAuthenticator.java:216)
        at org.apache.hadoop.security.authentication.client.AuthenticatedURL.openConnection(AuthenticatedURL.java:348)
        at org.apache.hadoop.hdfs.web.URLConnectionFactory.openConnection(URLConnectionFactory.java:186)
        at org.apache.hadoop.hdfs.server.federation.router.FederationUtil.getJmx(FederationUtil.java:82)
        at org.apache.hadoop.hdfs.server.federation.router.NamenodeHeartbeatService.updateJMXParameters(NamenodeHeartbeatService.java:343)
        at org.apache.hadoop.hdfs.server.federation.router.NamenodeHeartbeatService.getNamenodeStatusReport(NamenodeHeartbeatService.java:289)
        at org.apache.hadoop.hdfs.server.federation.router.NamenodeHeartbeatService.updateState(NamenodeHeartbeatService.java:216)
        at org.apache.hadoop.hdfs.server.federation.router.NamenodeHeartbeatService.periodicInvoke(NamenodeHeartbeatService.java:170)
        at org.apache.hadoop.hdfs.server.federation.router.PeriodicService$1.run(PeriodicService.java:178)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305)
        at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:131)
        at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:320)
        at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:263)
        at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:258)
        at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(CertificateMessage.java:1324)
        at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.onConsumeCertificate(CertificateMessage.java:1199)
        at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.consume(CertificateMessage.java:1146)
        at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:392)
        at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:443)
        at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:421)
        at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:177)
        at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:164)
        at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1152)
        at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1063)
        at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:402)
        at java.base/sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:567)
        at java.base/sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
        at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:168)
        at org.apache.hadoop.security.authentication.client.KerberosAuthenticator.authenticate(KerberosAuthenticator.java:189)
        ... 14 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at java.base/sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:385)
        at java.base/sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:290)
        at java.base/sun.security.validator.Validator.validate(Validator.java:264)
        at java.base/sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:313)
        at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:222)
        at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:129)
        at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(CertificateMessage.java:1308)
        ... 28 more