hadoop2.2.0 core-site.xml--Rack Configuration

<property>
<name>net.topology.node.switch.mapping.impl</name>
<value>org.apache.hadoop.net.ScriptBasedMapping</value>
<description> The default implementation of the DNSToSwitchMapping. It
invokes a script specified in net.topology.script.file.name to resolve
node names. If the value for net.topology.script.file.name is not set, the
default value of DEFAULT_RACK is returned for all node names.
</description>
</property>

<property>
<name>net.topology.script.file.name</name>
<value></value>
<description> The script name that should be invoked to resolve DNS names to
NetworkTopology names. Example: the script would take host.foo.bar as an
argument, and return /rack1 as the output.
</description>
</property>

<property>
<name>net.topology.script.number.args</name>
<value>100</value>
<description> The max number of args that the script configured with
net.topology.script.file.name should be run with. Each arg is an
IP address.
</description>
</property>