HIVE-29306: GSSException encountered during HMS Ranger authorization

Author: KiranVelumuri

standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/security/TUGIAssumingTransport.java

@@ -45,7 +45,8 @@ public TUGIAssumingTransport(TTransport wrapped, UserGroupInformation ugi) {
    @Override
    public void open() throws TTransportException {
      try {
-       ugi.doAs(new PrivilegedExceptionAction<Void>() {
+       UserGroupInformation loggedInUGI = ugi.getRealUser() != null ?  ugi.getRealUser() : ugi;
+       loggedInUGI.doAs(new PrivilegedExceptionAction<Void>() {
          public Void run() {
            try {
              wrapped.open();