4. Modify WebHCat Configuration Files

To modify the WebHCat config files:

Extract the WebHCat configuration files to a temporary directory.
The files are located in the configuration_files/webhcat directory where you decompressed the companion files.

Modify the configuration files.

In the temporary directory, locate the following files and modify the properties based on your environment.

Search for TODO variables in the files for the properties to replace.

Edit the webhcat-site.xml and modify the following properties:

<property> 
     <name>templeton.hive.properties</name>
     <value>hive.metastore.local=false,hive.metastore.uris=thrift://TODO-METASTORE-HOSTNAME:9083,hive.metastore.sasl.enabled=yes,hive.metastore.execute.setugi=true,hive.metastore.warehouse.dir=/apps/hive/warehouse</value> 
     <description>Properties to set when running Hive.</description>
</property>

<property> 
     <name>templeton.zookeeper.hosts</name> 
     <value>$zookeeper1.full.hostname:2181,$zookeeper1.full.hostname:2181,..</value> 
     <description>ZooKeeper servers, as comma separated HOST:PORT pairs.</description>
</property>

In core-site.xml, make sure the following properties are also set to allow WebHcat to impersonate groups and hosts:
```
<property>
     <name>hadoop.proxyuser.hcat.groups</name>
     <value>*</value>
</property> 

<property>
     <name>hadoop.proxyuser.hcat.hosts</name>
     <value>*</value>
</property> 
```
where:
- hadoop.proxyuser.hcat.group is a comma-separated list of the Unix groups whose users may be impersonated.
- hadoop.proxyuser.hcat.hosts is a comma-separated list of the hosts that are allowed to submit requests using hcat.

Set up the updated WebHCat configuration files.
1. Delete any existing WebHCat configuration files:
```
rm -rf $WEBHCAT_CONF_DIR/*
```
2. Copy all of the modified config files to $WEBHCAT_CONF_DIR and set appropriate permissions:
```
chown -R $WEBHCAT_USER:$HADOOP_GROUP $WEBHCAT_CONF_DIR
chmod -R 755 $WEBHCAT_CONF_DIR
```
  where:
  - $WEBHCAT_CONF_DIR is the directory to store theWebHCat configuration files. For example, /etc/hcatalog/conf/webhcat.
  - $WEBHCAT_USER is the user owning the WebHCat services. For example, hcat.
  - $HADOOP_GROUP is a common group shared by services. For example, hadoop.

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