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 2.7.4

Apache Hadoop 2.7.4 is a minor release in the 2.x.y release line, building upon the previous stable release 2.7.3.

It includes bug fixes, improvements, and optimizations including:

• Common

  • Metrics improvements.
  • Exponential back off for RPC clients.
  • Workaround for Jetty6 bugs.
  • Security fixes.
  • ViewFs improvements.
  • Fix unit tests failures.

• HDFS

  • DataNode-space-aware block placement policy.
  • Balancer evolution and optimization.
  • NameNode optimization.
  • Incremental block reports batching.
  • Block report processing optimization.
  • NameNode Metrics for queue length and lock usage.
  • NNThroughputBenchmark improvements.

• MAPREDUCE, YARN

  • Selective display of job conf properties on Job History WebUI.
  • Support for node labeling.
  • Synthetic Load Generator improvements.

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.