Core-site.xml trash interval, proxy set up for ambari running as root,rack awareness script

1.Trash is configured by two properties, fs.trash.checkpoint.interval and fs.trash.interval in core-site.xml.

2.In order to use the Ambari Files View, you need to setup an HDFS proxy user for the Ambari daemon

account.

For example, if the AmbariServer daemon is running as root, you configure a proxy user for root

in the Ambari Web UI by selecting:

Services > HDFS > Configs > Advanced > Custom coresite > Add Property

Add the properties and values(In core-site.xml)

 hadoop.proxyuser.root.groups=* and

hadoop.proxyuser.root.hosts=*

to the file as shown above. Save the changes and restart any affected services as indicated in the Ambari Web UI. This assumes that Ambari was installed and runs as the root user account. If this is not the case,

change root to the appropriate user account.

3. net.topology.script.file.name property Configuring rack awareness

/etc/hadoop/conf/topology_script.py. This script references the mapping file

/etc/hadoop/conf/topology_mapping.data

4. In Ambari when using existing MIT KDC /active directory to map users and groups in unix to Hadoop it uses a rule-based system to create mappings between service principals and their related UNIX usernames. The rules are specified using the configuration property hadoop.security.auth_to_local

=default