There are a number of special “users” with roles to play in the Apache Hadoop environment. For your reference, we have summarized them below as of CDH 4.4. Kerberos principals (used for authentication in a secure cluster) are not covered here.
The specific user IDs listed are the ones created by default on installation but they are configurable unless otherwise indicated.
The NameNode and DataNodes run as this user, Read More
For several good reasons, 2013 is a Happy New Year for Apache Hadoop enthusiasts.
In 2012, we saw continued progress on developing the next generation of the MapReduce processing framework (MRv2), work that will bear fruit this year. HDFS experienced major progress toward becoming a lights-out, fully enterprise-ready distributed filesystem with the addition of high availability features and increased performance. And a hint of the future of the Hadoop platform was provided with the Beta release of Cloudera Impala,
2011 was a breakthrough year for Apache Hadoop as many more mainstream organizations large and small turned to Hadoop to manage and process Big Data, while enterprise software and hardware vendors have also made Hadoop a prominent part of their offerings. Big Data and Hadoop became synonymous in much of the enterprise discourse, and Big Data interest is not restricted to Big Companies.
Apache Hadoop Releases
Hadoop had three major releases in 2011: 1.0 (AKA 0.20.205.x),