##### 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 0.19.2 - 2009-07-23

### INCOMPATIBLE CHANGES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-5332 | Make support for file append API configurable | Blocker | . | Nigel Daley | dhruba borthakur

### IMPROVEMENTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-5379 | Throw exception instead of writing to System.err when there is a CRC error on CBZip2InputStream | Minor | io | Rodrigo Schmidt | Rodrigo Schmidt

### BUG FIXES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-5269 | TaskTracker.runningTasks holding FAILED_UNCLEAN and KILLED_UNCLEAN taskStatuses forever in some cases. | Blocker | . | Amareshwari Sriramadasu | Amareshwari Sriramadasu
HADOOP-5233 | Reducer not Succeded after 100% | Blocker | . | Amareshwari Sriramadasu | Amareshwari Sriramadasu
HADOOP-5247 | NPEs in JobTracker and JobClient when mapred.jobtracker.completeuserjobs.maximum is set to zero. | Blocker | . | Vinod Kumar Vavilapalli | Amar Kamat
HADOOP-5285 | JobTracker hangs for long periods of time | Blocker | . | Vinod Kumar Vavilapalli | Devaraj Das
HADOOP-5241 | Reduce tasks get stuck because of over-estimated task size (regression from 0.18) | Blocker | . | Andy Pavlo | Sharad Agarwal
HADOOP-5280 | When expiring a lost launched task, JT doesn’t remove the attempt from the taskidToTIPMap. | Blocker | . | Vinod Kumar Vavilapalli | Devaraj Das
HADOOP-5154 | 4-way deadlock in FairShare scheduler | Blocker | . | Vinod Kumar Vavilapalli | Matei Zaharia
HADOOP-5146 | LocalDirAllocator misses files on the local filesystem | Blocker | . | Arun C Murthy | Devaraj Das
HADOOP-5326 | bzip2 codec (CBZip2OutputStream) creates corrupted output file for some inputs | Major | io | Rodrigo Schmidt | Rodrigo Schmidt
HADOOP-4638 | Exception thrown in/from RecoveryManager.recover() should be caught and handled | Blocker | . | Amar Kamat | Amar Kamat
HADOOP-5384 | DataNodeCluster should not create blocks with generationStamp == 1 | Blocker | test | Tsz Wo Nicholas Sze | Tsz Wo Nicholas Sze
HADOOP-5376 | JobInProgress.obtainTaskCleanupTask() throws an ArrayIndexOutOfBoundsException | Blocker | . | Vinod Kumar Vavilapalli | Amareshwari Sriramadasu
HADOOP-5421 | HADOOP-4638 has broken 0.19 compilation | Blocker | . | Amar Kamat | Devaraj Das
HADOOP-5392 | JobTracker crashes during recovery if job files are garbled | Blocker | . | Amar Kamat | Amar Kamat
HADOOP-5333 | The libhdfs append API is not coded correctly | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-3998 | Got an exception from ClientFinalizer when the JT is terminated | Blocker | . | Amar Kamat | dhruba borthakur
HADOOP-5440 | Successful taskid are not removed from TaskMemoryManager | Blocker | . | Amareshwari Sriramadasu | Amareshwari Sriramadasu
HADOOP-5446 | TaskTracker metrics are disabled | Major | metrics | Chris Douglas | Chris Douglas
HADOOP-5449 | Verify if JobHistory.HistoryCleaner works as expected | Blocker | . | Amar Kamat | Amareshwari Sriramadasu
HADOOP-5465 | Blocks remain under-replicated | Blocker | . | Hairong Kuang | Hairong Kuang
HADOOP-5479 | NameNode should not send empty block replication request to DataNode | Critical | . | Hairong Kuang | Hairong Kuang
HADOOP-5522 | Document job setup/cleaup tasks and task cleanup tasks in mapred tutorial | Blocker | . | Amareshwari Sriramadasu | Amareshwari Sriramadasu
HADOOP-5549 | ReplicationMonitor should schedule both replication and deletion work in one iteration | Major | . | Hairong Kuang | Hairong Kuang
HADOOP-5554 | DataNodeCluster should create blocks with the same generation stamp as the blocks created in CreateEditsLog | Major | test | Hairong Kuang | Hairong Kuang
HADOOP-5557 | Two minor problems in TestOverReplicatedBlocks | Minor | test | Tsz Wo Nicholas Sze | Tsz Wo Nicholas Sze
HADOOP-5231 | Negative number of maps in cluster summary | Major | . | Amareshwari Sriramadasu | Amareshwari Sriramadasu
HADOOP-4719 | The ls shell command documentation is out-dated | Major | documentation | Tsz Wo Nicholas Sze | Ravi Phulari
HADOOP-5374 | NPE in JobTracker.getTasksToSave() method | Major | . | Vinod Kumar Vavilapalli | Amareshwari Sriramadasu
HADOOP-4780 | Task Tracker burns a lot of cpu in calling getLocalCache | Major | . | Runping Qi | He Yongqiang
HADOOP-5551 | Namenode permits directory destruction on overwrite | Critical | . | Brian Bockelman | Brian Bockelman
HADOOP-5644 | Namnode is stuck in safe mode | Major | . | Suresh Srinivas | Suresh Srinivas
HADOOP-5671 | DistCp.sameFile(..) should return true if src fs does not support checksum | Major | . | Tsz Wo Nicholas Sze | Tsz Wo Nicholas Sze
HADOOP-5213 | BZip2CompressionOutputStream NullPointerException | Blocker | io | Zheng Shao | Zheng Shao
HADOOP-5579 | libhdfs does not set errno correctly | Major | . | Brian Bockelman | Brian Bockelman
HADOOP-5728 | FSEditLog.printStatistics may cause IndexOutOfBoundsException | Major | . | Wang Xu | Wang Xu
HADOOP-5816 | ArrayIndexOutOfBoundsException when using KeyFieldBasedComparator | Minor | . | Min Zhou | He Yongqiang
HADOOP-5951 | StorageInfo needs Apache license header. | Major | . | Suresh Srinivas | Suresh Srinivas
HADOOP-6017 | NameNode and SecondaryNameNode fail to restart because of abnormal filenames. | Blocker | . | Raghu Angadi | Tsz Wo Nicholas Sze