http://www.slideshare.net/hortonworks/apache-hadoop-023
HDFS Federation http://www.hortonworks.com/an-introduction-to-hdfs-federation/
Next Generation of Apache Hadoop MapReduce http://www.slideshare.net/hortonworks/nextgen-apache-hadoop-mapreduce
HDFS High Availablity https://issues.apache.org/jira/browse/HDFS-1623