##### 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 0.20.203.0 - 2011-05-11

### NEW FEATURES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-7108 | hadoop-0.20.100 | Major | . | Arun C Murthy | Arun C Murthy
HADOOP-4343 | Adding user and service-to-service authentication to Hadoop | Blocker | . | Kan Zhang | Kan Zhang

### IMPROVEMENTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
MAPREDUCE-478 | separate jvm param for mapper and reducer | Minor | . | Koji Noguchi | Arun C Murthy
HDFS-457 | better handling of volume failure in Data Node storage | Major | datanode | Boris Shkolnik | Boris Shkolnik
HDFS-1626 | Make BLOCK_INVALIDATE_LIMIT configurable | Minor | namenode | Arun C Murthy | Tsz Wo Nicholas Sze
MAPREDUCE-2316 | Update docs for CapacityScheduler | Major | capacity-sched, documentation | Arun C Murthy | Arun C Murthy
HADOOP-7247 | Fix documentation to reflect new jar names | Major | . | Owen O’Malley | Owen O’Malley
MAPREDUCE-1943 | Implement limits on per-job JobConf, Counters, StatusReport, Split-Sizes | Major | . | Mahadev konar | Mahadev konar
MAPREDUCE-2355 | Add an out of band heartbeat damper | Major | jobtracker | Owen O’Malley | Arun C Murthy

### BUG FIXES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-6907 | Rpc client doesn’t use the per-connection conf to figure out server’s Kerberos principal | Major | ipc, security | Kan Zhang | Kan Zhang
MAPREDUCE-1280 | Eclipse Plugin does not work with Eclipse Ganymede (3.4) | Major | . | Aaron Kimball | Alex Kozlov
HADOOP-7190 | Put metrics v1 back into the hadoop-20-security branch | Major | metrics | Owen O’Malley | Owen O’Malley
HADOOP-7232 | Fix javadoc warnings | Blocker | documentation | Owen O’Malley | Owen O’Malley
HADOOP-7143 | Hive Hadoop20SShims depends on removed HadoopArchives | Major | fs | Joep Rottinghuis | Joep Rottinghuis
HDFS-1822 | Editlog opcodes overlap between 20 security and later releases | Blocker | namenode | Suresh Srinivas | Suresh Srinivas
HADOOP-7246 | The default log4j configuration causes warnings about EventCounter | Major | . | Owen O’Malley | Luke Lu
HADOOP-7253 | Fix default config | Major | . | Owen O’Malley | Owen O’Malley
HDFS-1022 | Merge under-10-min tests specs into one file | Major | test | Erik Steffl | Erik Steffl
HADOOP-7259 | contrib modules should include build.properties from parent. | Major | build | Owen O’Malley | Owen O’Malley
HADOOP-7215 | RPC clients must connect over a network interface corresponding to the host name in the client’s kerberos principal key | Blocker | security | Suresh Srinivas | Suresh Srinivas
HADOOP-7258 | Gzip codec should not return null decompressors | Major | . | Owen O’Malley | Owen O’Malley
HADOOP-5647 | TestJobHistory fails if /tmp/_logs is not writable to. Testcase should not depend on /tmp | Major | test | Ravi Gummadi | Ravi Gummadi
HADOOP-7040 | DiskChecker:mkdirsWithExistsCheck swallows FileNotFoundException. | Major | . | Boris Shkolnik | Boris Shkolnik
MAPREDUCE-2365 | Add counters for FileInputFormat (BYTES_READ) and FileOutputFormat (BYTES_WRITTEN) | Major | . | Owen O’Malley | Siddharth Seth
HADOOP-7163 | “java.net.SocketTimeoutException: 60000 millis timeout” happens a lot | Major | ipc | Owen O’Malley | Devaraj Das
HADOOP-7243 | Fix contrib unit tests (fairshare, hdfsproxy, datajoin, streaming) | Major | . | Owen O’Malley | Owen O’Malley
MAPREDUCE-323 | Improve the way job history files are managed | Critical | jobtracker | Amar Kamat | Dick King
MAPREDUCE-2278 | DistributedCache shouldn’t hold a ref to JobConf | Major | distributed-cache, tasktracker | Arun C Murthy | Chris Douglas
MAPREDUCE-1699 | JobHistory shouldn’t be disabled for any reason | Major | jobtracker | Arun C Murthy | Krishna Ramachandran
MAPREDUCE-1118 | Capacity Scheduler scheduling information is hard to read / should be tabular format | Major | capacity-sched | Allen Wittenauer | Krishna Ramachandran
MAPREDUCE-1233 | Incorrect Waiting maps/reduces in Jobtracker metrics | Major | jobtracker | V.Karthikeyan | Luke Lu