##### General

- Overview
- Single Node Setup
- Cluster Setup
- Commands Reference
- FileSystem Shell
- Compatibility Specification
- Downstream Developer's Guide
- Admin Compatibility Guide
- Interface Classification
- FileSystem Specification

##### Common

- CLI Mini Cluster
- Native Libraries
- Proxy User
- Rack Awareness
- Secure Mode
- Service Level Authorization
- HTTP Authentication
- Credential Provider API
- Hadoop KMS
- Tracing
- Unix Shell Guide

##### HDFS

- Architecture
- User Guide
- Commands Reference
- NameNode HA With QJM
- NameNode HA With NFS
- Observer NameNode
- Federation
- ViewFs
- ViewFsOverloadScheme
- Snapshots
- Edits Viewer
- Image Viewer
- Permissions and HDFS
- Quotas and HDFS
- libhdfs (C API)
- WebHDFS (REST API)
- HttpFS
- Short Circuit Local Reads
- Centralized Cache Management
- NFS Gateway
- Rolling Upgrade
- Extended Attributes
- Transparent Encryption
- Multihoming
- Storage Policies
- Memory Storage Support
- Synthetic Load Generator
- Erasure Coding
- Disk Balancer
- Upgrade Domain
- DataNode Admin
- Router Federation
- Provided Storage

##### MapReduce

- Tutorial
- Commands Reference
- Compatibility with 1.x
- Encrypted Shuffle
- Pluggable Shuffle/Sort
- Distributed Cache Deploy
- Support for YARN Shared Cache

##### MapReduce REST APIs

- MR Application Master
- MR History Server

##### YARN

- Architecture
- Commands Reference
- Capacity Scheduler
- Fair Scheduler
- ResourceManager Restart
- ResourceManager HA
- Resource Model
- Node Labels
- Node Attributes
- Web Application Proxy
- Timeline Server
- Timeline Service V.2
- Writing YARN Applications
- YARN Application Security
- NodeManager
- Running Applications in Docker Containers
- Using CGroups
- Secure Containers
- Registry
- Reservation System
- Graceful Decommission
- Opportunistic Containers
- YARN Federation
- Shared Cache
- Using GPU
- Using FPGA
- Placement Constraints
- YARN UI2

##### YARN REST APIs

- Introduction
- Resource Manager
- Node Manager
- Timeline Server
- Timeline Service V.2

##### YARN Service

- Overview
- QuickStart
- Concepts
- Yarn Service API
- Service Discovery
- System Services

##### Submarine

- Index
- QuickStart
- Examples

##### Hadoop Compatible File Systems

- Aliyun OSS
- Amazon S3
- Azure Blob Storage
- Azure Data Lake Storage
- OpenStack Swift

##### Auth

- Overview
- Examples
- Configuration
- Building

##### Tools

- Hadoop Streaming
- Hadoop Archives
- Hadoop Archive Logs
- DistCp
- GridMix
- Rumen
- Resource Estimator Service
- Scheduler Load Simulator
- Hadoop Benchmarking

##### Reference

- Changelog and Release Notes
- Java API docs
- Unix Shell API
- Metrics

##### Configuration

- core-default.xml
- hdfs-default.xml
- hdfs-rbf-default.xml
- mapred-default.xml
- yarn-default.xml
- kms-default.xml
- httpfs-default.xml
- Deprecated Properties

# Apache Hadoop Changelog

## Release 0.23.4 - 2012-10-15

### NEW FEATURES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-7788 | HA: Simple HealthMonitor class to watch an HAService | Major | ha | Todd Lipcon | Todd Lipcon
MAPREDUCE-4651 | Benchmarking random reads with DFSIO | Major | benchmarks, test | Konstantin Shvachko | Konstantin Shvachko

### IMPROVEMENTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-8183 | Stop using “mapred.used.genericoptionsparser” to avoid unnecessary warnings | Minor | util | Harsh J | Harsh J
HADOOP-8623 | hadoop jar command should respect HADOOP_OPTS | Minor | scripts | Steven Willis | Steven Willis
MAPREDUCE-4408 | allow jobs to set a JAR that is in the distributed cached | Major | mrv1, mrv2 | Alejandro Abdelnur | Robert Kanter
MAPREDUCE-2786 | TestDFSIO should also test compression reading/writing from command-line. | Minor | benchmarks | Plamen Jeliazkov | Plamen Jeliazkov
YARN-57 | Plugable process tree | Major | nodemanager | Radim Kolar | Radim Kolar
MAPREDUCE-4645 | Providing a random seed to Slive should make the sequence of filenames completely deterministic | Major | performance, test | Ravi Prakash | Ravi Prakash
YARN-137 | Change the default scheduler to the CapacityScheduler | Major | scheduler | Siddharth Seth | Siddharth Seth

### BUG FIXES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
MAPREDUCE-4193 | broken doc link for yarn-default.xml in site.xml | Major | documentation | Patrick Hunt | Patrick Hunt
HADOOP-8310 | FileContext#checkPath should handle URIs with no port | Major | fs | Aaron T. Myers | Aaron T. Myers
HDFS-3860 | HeartbeatManager#Monitor may wrongly hold the writelock of namesystem | Major | . | Jing Zhao | Jing Zhao
HADOOP-8684 | Deadlock between WritableComparator and WritableComparable | Minor | io | Hiroshi Ikeda | Jing Zhao
YARN-42 | Node Manager throws NPE on startup | Major | nodemanager | Devaraj K | Devaraj K
YARN-75 | RMContainer should handle a RELEASE event while RUNNING | Major | . | Siddharth Seth | Siddharth Seth
MAPREDUCE-4646 | client does not receive job diagnostics for failed jobs | Major | mrv2 | Jason Lowe | Jason Lowe
YARN-93 | Diagnostics missing from applications that have finished but failed | Major | resourcemanager | Jason Lowe | Jason Lowe
YARN-108 | FSDownload can create cache directories with the wrong permissions | Critical | nodemanager | Jason Lowe | Jason Lowe
YARN-88 | DefaultContainerExecutor can fail to set proper permissions | Major | nodemanager | Jason Lowe | Jason Lowe
HADOOP-8822 | relnotes.py was deleted post mavenization | Major | . | Robert Joseph Evans | Robert Joseph Evans
MAPREDUCE-4647 | We should only unjar jobjar if there is a lib directory in it. | Major | mrv2 | Robert Joseph Evans | Robert Joseph Evans
HADOOP-8843 | Old trash directories are never deleted on upgrade from 1.x | Critical | . | Robert Joseph Evans | Jason Lowe
HDFS-3831 | Failure to renew tokens due to test-sources left in classpath | Critical | security | Jason Lowe | Jason Lowe
HDFS-3922 | 0.22 and 0.23 namenode throws away blocks under construction on restart | Critical | namenode | Kihwal Lee | Kihwal Lee
HDFS-3731 | 2.0 release upgrade must handle blocks being written from 1.0 | Blocker | datanode | Suresh Srinivas | Kihwal Lee
HDFS-3373 | FileContext HDFS implementation can leak socket caches | Major | hdfs-client | Todd Lipcon | John George
YARN-106 | Nodemanager needs to set permissions of local directories | Major | nodemanager | Jason Lowe | Jason Lowe
MAPREDUCE-4691 | Historyserver can report “Unknown job” after RM says job has completed | Critical | jobhistoryserver, mrv2 | Jason Lowe | Robert Joseph Evans
MAPREDUCE-4689 | JobClient.getMapTaskReports on failed job results in NPE | Major | client | Jason Lowe | Jason Lowe
YARN-138 | Improve default config values for YARN | Major | resourcemanager, scheduler | Arun C Murthy | Harsh J
HDFS-3626 | Creating file with invalid path can corrupt edit log | Blocker | namenode | Todd Lipcon | Todd Lipcon
HDFS-3553 | Hftp proxy tokens are broken | Blocker | . | Daryn Sharp | Daryn Sharp