##### 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 0.12.0 - 2007-03-02

### NEW FEATURES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-491 | streaming jobs should allow programs that don’t do any IO for a long time | Major | . | arkady borkovsky | Arun C Murthy
HADOOP-492 | Global counters | Major | . | arkady borkovsky | David Bowen
HADOOP-1032 | Support for caching Job JARs | Minor | . | Gautam Kowshik | Gautam Kowshik

### IMPROVEMENTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-975 | Separation of user tasks’ stdout and stderr streams | Major | . | Arun C Murthy | Arun C Murthy
HADOOP-982 | A couple setter functions and toString method for BytesWritable. | Major | io | Owen O’Malley | Owen O’Malley
HADOOP-858 | clean up smallJobsBenchmark and move to src/test/org/apache/hadoop/mapred | Minor | build | Nigel Daley | Nigel Daley
HADOOP-954 | Metrics should offer complete set of static report methods or none at all | Minor | metrics | Nigel Daley | David Bowen
HADOOP-882 | S3FileSystem should retry if there is a communication problem with S3 | Major | fs | Tom White | Tom White
HADOOP-977 | The output from the user’s task should be tagged and sent to the resepective console streams. | Major | . | Owen O’Malley | Arun C Murthy
HADOOP-1007 | Names used for map, reduce, and shuffle metrics should be unique | Trivial | metrics | Nigel Daley | Nigel Daley
HADOOP-889 | DFS unit tests have duplicate code | Minor | test | Doug Cutting | Milind Bhandarkar
HADOOP-943 | fsck to show the filename of the corrupted file | Trivial | . | Koji Noguchi | dhruba borthakur
HADOOP-333 | we should have some checks that the sort benchmark generates correct outputs | Major | . | Owen O’Malley | Arun C Murthy
HADOOP-1017 | Optimization: Reduce Overhead from ReflectionUtils.newInstance | Major | util | Ron Bodkin |
HADOOP-867 | job client should generate input fragments before the job is submitted | Major | . | Owen O’Malley |
HADOOP-952 | Create a public (shared) Hadoop EC2 AMI | Major | scripts | Tom White | Tom White
HADOOP-1025 | remove dead code in Server.java | Minor | ipc | Doug Cutting | Doug Cutting
HADOOP-997 | Implement S3 retry mechanism for failed block transfers | Major | fs | Tom White | Tom White
HADOOP-1030 | in unit tests, set ipc timeout in one place | Minor | test | Doug Cutting | Doug Cutting
HADOOP-985 | Namenode should identify DataNodes as ip:port instead of hostname:port | Major | . | Raghu Angadi | Raghu Angadi
HADOOP-248 | locating map outputs via random probing is inefficient | Major | . | Owen O’Malley | Devaraj Das
HADOOP-1040 | Improvement of RandomWriter example to use custom InputFormat, OutputFormat, and Counters | Major | . | Owen O’Malley | Owen O’Malley
HADOOP-928 | make checksums optional per FileSystem | Major | fs | Doug Cutting | Hairong Kuang
HADOOP-1042 | Improve the handling of failed map output fetches | Major | . | Devaraj Das | Devaraj Das
HADOOP-972 | Improve the rack-aware replica placement performance | Major | . | Hairong Kuang | Hairong Kuang
HADOOP-1043 | Optimize the shuffle phase (increase the parallelism) | Major | . | Devaraj Das | Devaraj Das
HADOOP-940 | pendingReplications of FSNamesystem is not informative | Major | . | Hairong Kuang | dhruba borthakur
HADOOP-941 | Enhancements to Hadoop record I/O - Part 1 | Major | record | Milind Bhandarkar | Milind Bhandarkar
HADOOP-1041 | Counter names are ugly | Major | . | Owen O’Malley | David Bowen
HADOOP-432 | support undelete, snapshots, or other mechanism to recover lost files | Major | . | Yoram Arnon | Doug Cutting
HADOOP-1033 | Rewrite AmazonEC2 wiki page | Minor | scripts | Tom White | Tom White

### BUG FIXES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-992 | The mini/mr cluster for testing always uses the local file system rather than the namenode that was passed in | Major | test | Owen O’Malley | Owen O’Malley
HADOOP-893 | dead datanode set should be maintained in the file handle or file system for hdfs | Major | . | Owen O’Malley | Raghu Angadi
HADOOP-761 | Unit tests should cleanup created files in /tmp. It causes tests to fail if more than one users run tests on same machine. | Minor | test | Sanjay Dahiya | Nigel Daley
HADOOP-1010 | getReordReader methof of InputFormat class should handle null reporter argument | Major | . | Runping Qi | Runping Qi
HADOOP-923 | DFS Scalability: datanode heartbeat timeouts cause cascading timeouts of other datanodes | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-476 | Streaming should check for correctness of the task | Major | . | arkady borkovsky | Arun C Murthy
HADOOP-973 | NPE in FSDataset during heavy Namenode load | Major | . | Nigel Daley | dhruba borthakur
HADOOP-649 | Jobs without any map and reduce operations seems to be lost after their execution | Major | . | Thomas Friol | Owen O’Malley
HADOOP-803 | Reducing memory consumption on Namenode : Part 1 | Major | . | Raghu Angadi | Raghu Angadi
HADOOP-1021 | TestMiniMRLocalFS and TestMiniMRCaching broken on Windows | Major | test | Nigel Daley |
HADOOP-947 | isReplicationInProgress() is very heavyweight | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-442 | slaves file should include an ‘exclude’ section, to prevent “bad” datanodes and tasktrackers from disrupting a cluster | Major | conf | Yoram Arnon | Wendy Chien
HADOOP-933 | Application defined InputSplits do not work | Major | . | Benjamin Reed | Owen O’Malley
HADOOP-1006 | The “-local” option does work properly with test programs | Minor | test | Gautam Kowshik | Doug Cutting
HADOOP-990 | Datanode doesn’t retry when write to one (full)drive fail | Major | . | Koji Noguchi | Raghu Angadi
HADOOP-564 | we should use hdfs:// in all API URIs | Major | . | eric baldeschwieler | Wendy Chien
HADOOP-654 | jobs fail with some hardware/system failures on a small number of nodes | Minor | . | Yoram Arnon | Arun C Murthy
HADOOP-1029 | streaming doesn’t work with multiple maps | Blocker | . | Arun C Murthy | Arun C Murthy
HADOOP-1034 | RuntimeException and Error not catched in DataNode.DataXceiver.run() | Major | . | Philippe Gassmann |
HADOOP-878 | reducer NONE does not work with multiple maps | Minor | . | Mahadev konar | Arun C Murthy
HADOOP-1039 | Reduce the time taken by TestCheckpoint | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1027 | Fix the RAM FileSystem/Merge problems (reported in HADOOP-1014) | Major | . | Devaraj Das | Devaraj Das
HADOOP-1036 | task gets lost during assignment | Critical | . | Owen O’Malley | Arun C Murthy
HADOOP-1044 | TestDecommission fails because it attempts to transfer block to a dead datanode | Major | test | Wendy Chien | Wendy Chien
HADOOP-109 | Blocks are not replicated when… | Major | . | Konstantin Shvachko | Konstantin Shvachko
HADOOP-1020 | Path class on Windows seems broken | Major | . | Nigel Daley | Doug Cutting
HADOOP-1000 | Loggers in the Task framework should not write the the Tasks stderr | Major | . | Owen O’Malley | Arun C Murthy
HADOOP-1037 | bin/slaves.sh not compatible with /bin/dash | Major | . | Doug Cutting |
HADOOP-1046 | Datanode should periodically clean up /tmp from partially received (and not completed) block files | Major | . | Andrzej Bialecki | Andrzej Bialecki
HADOOP-1049 | race condition in setting up ipc connections | Major | ipc | Owen O’Malley | Devaraj Das
HADOOP-1056 | Decommission only recognizes IP addesses in hosts and exclude files on refresh. | Major | . | Wendy Chien | Wendy Chien
HADOOP-994 | DFS Scalability : a BlockReport that returns large number of blocks-to-be-deleted cause datanode to lost connectivity to namenode | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-338 | the number of maps in the JobConf does not match reality | Major | . | Owen O’Malley | Owen O’Malley

### TESTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-1051 | Add checkstyle target to ant build file | Major | build, test | Tom White | Tom White