What is the difference between varname and hivename in MetastoreConf.java?

[qq]

What is the difference between varname and hivename in the picture below?

How is the Hive MetaStore authenticated for accessing HDFS?

[qq]

Hey,


How is the Hive MetaStore authenticated for accessing HDFS?
Will it be automatically re-certified when the 
certification expires?
Is it related to hive.metastore.kerberos.key.file 
and hive.metastore.kerberos.principal?

Thank you