Set HADOOP_PROXY_USER cause hiveMetaStoreClient close everytime

In order to use proxy user to access hive metastore server with kerberos, I set HADOOP_PROXY_USER = proxy user.

this is the code of  HiveMetaStoreClient

but when I run a spark job with hive metatsore client, the connection to  hive metatsore server always close 

and I notice that some log before close :

Mestastore configuration hive.metastore.token.signature changed from DelegationTokenForHiveMetaStoreServer to

so we can find why the connection close always,  hive metatsore client will compare  currentMetaVars with hiveconf

but if we set HADOOP_PROXY_USER and init  hive metatsore client, the  ConfVars.METASTORE_TOKEN_SIGNATURE always is set

so I think this solutions can fix the bug:

ConfVars.METASTORE_TOKEN_SIGNATURE  is no need to check in hive metatsore client

obviously that is no more close