This library will change hadoop 1.0.X to use the DistributedNameNode.

Features
========

Create files, allocates blocks, deletes files/blocks, renames files.

Non-features
============
Replication
File Permissions
Atomic deletion, rename, directory creation, file creation... really, anything.
Balancing
Decommissioning
Client Locality (selecting a datanode for a replica close to the client)
Deleting large directories may fail due to OOM

Installation
============

Add this near the start of your hadoop-env.sh file:

ACCUMULO=/my/accumulo/directory
ZOOKEEPER=/my/zookeeper/directory
export HADOOP_CLASSPATH=/local/ecnewt2/workspace/distnn/target/classes:/local/ecnewt2/Installed/hbase/hbase-0.94.0.jar:zookeeper-3.4.3.jar
export HADOOP_CLASSPATH="$HADOOP_CLASSPATH:$ACCUMULO/lib/*"
export HADOOP_CLASSPATH="$HADOOP_CLASSPATH:$ACCUMULO/conf"
export HADOOP_CLASSPATH="$HADOOP_CLASSPATH:$ZOOKEEPER/zookeeper-3.4.3.jar"
export HADOOP_USER_CLASSPATH_FIRST=true

Edit bin/start-dfs.sh to prevent the namenode and secondary namenode from starting.

Add the following to your hadoop-core.xml file:

  <property>
    <name>fs.default.name</name>
    <value>dnn://localhost:1337/user:passwd@instance:zookeeper1,zookeeper2,zookeeper3</value>
  </property>

  <property>
    <name>fs.dnn.impl</name>
    <value>org.apache.hadoop.hdfs.DNNFileSystem</value>
  </property>

TODO: make this unnecessary
Add the following to your hdfs-site.xml file:

  <property>
    <name>accumulo.zookeeper.instance</name>
    <value>test</value>
  </property>

  <property>
    <name>accumulo.zookeeper.keepers</name>
    <value>rd6ul-14706v.tycho.ncsc.mil</value>
  </property>

Replace the classpath in your accumulo-site.xml:

    <property>
      <name>general.classpaths</name>
      <value>
      /my/local/distnn/target/classes,
    $ACCUMULO_HOME/src/server/target/classes/,
    $ACCUMULO_HOME/src/core/target/classes/,
    $ACCUMULO_HOME/src/start/target/classes/,
    $ACCUMULO_HOME/src/examples/target/classes/,
        $ACCUMULO_HOME/lib/[^.].$ACCUMULO_VERSION.jar,
        $ACCUMULO_HOME/lib/[^.].*.jar,
        $ZOOKEEPER_HOME/zookeeper[^.].*.jar,
        $HADOOP_HOME/conf,
        $HADOOP_HOME/[^.].*.jar,
        $HADOOP_HOME/lib/[^.].*.jar,
      </value>
      <description>Classpaths that accumulo checks for updates and class files.
      When using the Security Manager, please remove the ".../target/classes/" values.
      </description>
    </property>