General

• Overview
• Single Node Setup
• Cluster Setup
• Hadoop Commands Reference
• FileSystem Shell
• Hadoop Compatibility
• Interface Classification
• FileSystem Specification

Common

• CLI Mini Cluster
• Native Libraries
• Proxy User
• Rack Awareness
• Secure Mode
• Service Level Authorization
• HTTP Authentication
• Hadoop KMS
• Tracing

HDFS

• HDFS User Guide
• HDFS Commands Reference
• High Availability With QJM
• High Availability With NFS
• Federation
• ViewFs Guide
• HDFS Snapshots
• HDFS Architecture
• Edits Viewer
• Image Viewer
• Permissions and HDFS
• Quotas and HDFS
• HFTP
• C API libhdfs
• WebHDFS REST API
• HttpFS Gateway
• Short Circuit Local Reads
• Centralized Cache Management
• HDFS NFS Gateway
• HDFS Rolling Upgrade
• Extended Attributes
• Transparent Encryption
• HDFS Support for Multihoming
• Archival Storage, SSD & Memory
• Memory Storage Support

MapReduce

• MapReduce Tutorial
• MapReduce Commands Reference
• Compatibilty between Hadoop 1.x and Hadoop 2.x
• Encrypted Shuffle
• Pluggable Shuffle/Sort
• Distributed Cache Deploy

MapReduce REST APIs

• MR Application Master
• MR History Server

YARN

• Overview
• YARN Architecture
• Capacity Scheduler
• Fair Scheduler
• ResourceManager Restart
• ResourceManager HA
• Node Labels
• Web Application Proxy
• YARN Timeline Server
• Writing YARN Applications
• YARN Commands
• NodeManager Restart
• YARN Application Security
• DockerContainerExecutor
• Using CGroups
• Secure Containers
• Registry

YARN REST APIs

• Introduction
• Resource Manager
• Node Manager
• Timeline Server

Hadoop Compatible File Systems

• Amazon S3
• Azure Blob Storage
• OpenStack Swift

Auth

• Overview
• Examples
• Configuration
• Building

Tools

• Hadoop Streaming
• Hadoop Archives
• DistCp
• GridMix
• Rumen
• Scheduler Load Simulator

Reference

• Release Notes
• API docs
• Common CHANGES.txt
• HDFS CHANGES.txt
• MapReduce CHANGES.txt
• YARN CHANGES.txt
• Metrics

Configuration

• core-default.xml
• hdfs-default.xml
• mapred-default.xml
• yarn-default.xml
• Deprecated Properties

Apache Hadoop 2.7.3

Apache Hadoop 2.7.3 is a minor release in the 2.x.y release line, building upon the previous stable release 2.7.2.

Here is a short overview of the major features and improvements.

• Common

  • Authentication improvements when using an HTTP proxy server. This is useful when accessing WebHDFS via a proxy server.
  • A new Hadoop metrics sink that allows writing directly to Graphite.
  • Specification work related to the Hadoop Compatible Filesystem (HCFS) effort.

• HDFS

  • Support for POSIX-style filesystem extended attributes. See the user documentation for more details.
  • Using the OfflineImageViewer, clients can now browse an fsimage via the WebHDFS API.
  • The NFS gateway received a number of supportability improvements and bug fixes. The Hadoop portmapper is no longer required to run the gateway, and the gateway is now able to reject connections from unprivileged ports.
  • The SecondaryNameNode, JournalNode, and DataNode web UIs have been modernized with HTML5 and Javascript.

• YARN

  • YARN’s REST APIs now support write/modify operations. Users can submit and kill applications through REST APIs.
  • The timeline store in YARN, used for storing generic and application-specific information for applications, supports authentication through Kerberos.
  • The Fair Scheduler supports dynamic hierarchical user queues, user queues are created dynamically at runtime under any specified parent-queue.

Getting Started

The Hadoop documentation includes the information you need to get started using Hadoop. Begin with the Single Node Setup which shows you how to set up a single-node Hadoop installation. Then move on to the Cluster Setup to learn how to set up a multi-node Hadoop installation.