Sunil's Notes: WebHDFS REST API

Hadoop provides HTTP REST API interface that exposes access to HDFS using REST API. The WebHDFS provides ability to read and write files in HDFS and also provides support for all operations. It also provides security using Kerberos (SPNEGO) and Hadoop delegation tokens for authentication. You can find more information about it here I wanted to try WebHDFS API, so i followed these steps, first i changed the hdfs-site.xml file and changed it to set value of dfs.webhdfs.enabled property to true.

	<?xml version="1.0" encoding="UTF-8"?>
	<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
	<!--
	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License. See accompanying LICENSE file.
	-->

	<!-- Put site-specific property overrides in this file. -->

	<configuration>
	<property>
	<name>dfs.replication</name>
	<value>1</value>
	</property>
	<property>
	<name>dfs.namenode.name.dir</name>
	<value>file:/var/data/hadoop/hdfs/nn</value>
	</property>
	<property>
	<name>dfs.checkpoint.dir</name>
	<value>file:/var/data/hadoop/hdfs/snn</value>
	</property>
	<property>
	<name>dfs.checkpoints.edits.dir</name>
	<value>file:/var/data/hadoop/hdfs/snn</value>
	</property>
	<property>
	<name>dfs.datanode.data.dir</name>
	<value>file:/var/data/hadoop/hdfs/dn</value>
	</property>
	<property>
	<name>dfs.webhdfs.enabled</name>
	<value>true</value>
	</property>
	</configuration>