One more simple thing, that had relatively scarce documentation out on the Internet. As you might know, Hadoop NameNodes finally became HA in 2.0 . The HDFS client configuration, which is already a little bit tedious, became more complicated. Traditionally, there were two ways to configure a HDFS client (lets stick to Java) Copy over the entire Hadoop config directory with all the xml files, place it somewhere in the classpath of your app or construct a Hadoop Configuration object by manually adding in those files. Simply provide the HDFS NameNode URI and let the client do the rest. Configuration conf = new Configuration(false); conf.set("fs.default.name", "hdfs://localhost:8020"); // this is deprecated now conf.set("fs.defaultFS", "hdfs://localhost:8020"); FileSystem fs = FileSystem.get(conf); Most people prefer 2, unless you need way more configs from the actual xml config files, at which po