##### 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 0.13.0 - 2007-06-08

### NEW FEATURES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-1120 | Contribute some code helping implement map/reduce apps for joining data from multiple sources | Major | . | Runping Qi | Runping Qi
HADOOP-702 | DFS Upgrade Proposal | Major | . | Konstantin Shvachko | Konstantin Shvachko
HADOOP-1217 | Specify a junit test timeout in build.xml files | Minor | build | Nigel Daley | Nigel Daley
HADOOP-1251 | A method to get the InputSplit from a Mapper | Major | . | Owen O’Malley | Owen O’Malley
HADOOP-1111 | Job completion notification to a job configured URL | Major | . | Alejandro Abdelnur |
HADOOP-1216 | Hadoop should support reduce none option | Major | . | Runping Qi | Runping Qi
HADOOP-1247 | Make Hadoop Abacus work with Hadoop Streaming | Major | . | Runping Qi | Runping Qi
HADOOP-485 | allow a different comparator for grouping keys in calls to reduce | Major | . | Owen O’Malley | Tahir Hashmi

### IMPROVEMENTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-1101 | Add more statistics in the web-ui to do with tasks | Major | . | Devaraj Das | Devaraj Das
HADOOP-1116 | Add maxmemory=“256m” in the junit call of build-contrib.xml | Major | build | Philippe Gassmann |
HADOOP-1094 | Optimize readFields and write methods in record I/O | Major | record | Milind Bhandarkar | Milind Bhandarkar
HADOOP-1068 | Improve error message for 0 datanode case | Major | . | Owen O’Malley | dhruba borthakur
HADOOP-1131 | Add a closeAll() static method to FileSystem | Minor | . | Philippe Gassmann |
HADOOP-1165 | Code for toString in code generated by Record I/O Compiler can be generic | Minor | record | Milind Bhandarkar | Milind Bhandarkar
HADOOP-1166 | Pull the NullOutputFormat into the lib package | Major | . | Owen O’Malley | Owen O’Malley
HADOOP-1167 | InMemoryFileSystem uses synchronizedtMaps with maps that are locked anyways | Minor | fs | Owen O’Malley | Owen O’Malley
HADOOP-1194 | map output should not do block level compression | Major | . | Runping Qi | Arun C Murthy
HADOOP-1133 | Tools to analyze and debug namenode on a production cluster | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-988 | Namenode should use single map for block to its meta data. | Major | . | Raghu Angadi | Raghu Angadi
HADOOP-978 | AlreadyBeingCreatedException detail message could contain more useful info | Minor | . | Nigel Daley | Konstantin Shvachko
HADOOP-971 | DFS Scalabilty: Improve name node performance by adding a hostname to datanodes map | Major | . | Hairong Kuang | Hairong Kuang
HADOOP-819 | LineRecordWriter should not always insert tab char between key and value | Major | . | Runping Qi | Runping Qi
HADOOP-1213 | When RPC call fails then log call message detail | Minor | ipc | Nigel Daley | Doug Cutting
HADOOP-1250 | Remove the MustangFile class from streaming and promote the chmod into FileUtils | Major | . | Owen O’Malley | Owen O’Malley
HADOOP-1214 | the first step for streaming clean up | Major | . | Runping Qi | Runping Qi
HADOOP-1148 | re-indent all code | Minor | . | Doug Cutting | Doug Cutting
HADOOP-968 | Reduce shuffle and merge should be done a child JVM | Major | . | Owen O’Malley | Devaraj Das
HADOOP-1260 | need code review guidelines | Major | build | Nigel Daley | Nigel Daley
HADOOP-1190 | Fix unchecked warnings | Major | . | Tom White | Tom White
HADOOP-1127 | Speculative Execution and output of Reduce tasks | Major | . | Arun C Murthy | Arun C Murthy
HADOOP-1284 | clean up the protocol between stream mapper/reducer and the framework | Major | . | Runping Qi | Runping Qi
HADOOP-1290 | Move Hadoop Abacus to hadoop.mapred.lib | Major | . | Runping Qi |
HADOOP-1304 | MAX_TASK_FAILURES should be configurable | Major | . | Christian Kunz | Devaraj Das
HADOOP-1308 | Tighten generic Class restrictions in JobConf.java | Minor | . | Michael Bieniosek | Michael Bieniosek
HADOOP-1315 | Hadoop Streaming code clean up | Major | . | Runping Qi | Runping Qi
HADOOP-1144 | Hadoop should allow a configurable percentage of failed map tasks before declaring a job failed. | Major | . | Christian Kunz | Arun C Murthy
HADOOP-1263 | retry logic when dfs exist or open fails temporarily, e.g because of timeout | Major | . | Christian Kunz | Hairong Kuang
HADOOP-1276 | TaskTracker expiry interval is not configurable | Major | . | Alejandro Abdelnur | Arun C Murthy
HADOOP-1326 | Return the RunningJob from JobClient.runJob | Major | . | Owen O’Malley | Owen O’Malley
HADOOP-1270 | Randomize the fetch of map outputs | Major | . | Arun C Murthy | Arun C Murthy
HADOOP-1324 | FSError encountered by one running task should not be fatal to other tasks on that node | Major | . | Devaraj Das | Arun C Murthy
HADOOP-1161 | need improved release process | Major | build | Doug Cutting | Doug Cutting

### BUG FIXES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-1047 | TestReplication fails because DFS does not guarantee all the replicas are placed when a file is closed | Major | . | Hairong Kuang | Hairong Kuang
HADOOP-1063 | MiniDFSCluster exists a race condition that lead to data node resources are not properly released | Major | test | Hairong Kuang | Hairong Kuang
HADOOP-1071 | RPC$VersionMismatch exception is not fatal to JobTracker | Major | . | Nigel Daley | Tahir Hashmi
HADOOP-1064 | dfsclient logging messages should have appropriate log levels | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1137 | StatusHttpServer assumes that resources for /static are in files | Major | . | Benjamin Reed |
HADOOP-1122 | Divide-by-zero exception in chooseTarget | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1085 | Remove ‘port rolling’ from Mini{DFS|MR}Cluster | Major | test | Arun C Murthy | Arun C Murthy
HADOOP-1153 | DataNode and FSNamesystem don’t shutdown cleanly | Major | . | Nigel Daley | Konstantin Shvachko
HADOOP-1146 | “Reduce input records” counter name is misleading | Major | . | David Bowen | David Bowen
HADOOP-1164 | TestReplicationPolicy doesn’t use port 0 for the NameNode | Major | test | Owen O’Malley | Owen O’Malley
HADOOP-1169 | CopyFiles skips src files of s3 urls | Minor | util | stack |
HADOOP-1110 | JobTracker WebUI “Map input records” a little off. | Trivial | . | Koji Noguchi | David Bowen
HADOOP-1178 | NullPointer Exception in org.apache.hadoop.dfs.NameNode.isDir on namenode restart | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1011 | ConcurrentModificationException in JobHistory | Major | . | Nigel Daley | Tahir Hashmi
HADOOP-672 | dfs shell enhancements | Minor | . | Yoram Arnon | dhruba borthakur
HADOOP-1170 | Very high CPU usage on data nodes because of FSDataset.checkDataDir() on every connect | Major | . | Igor Bolotin |
HADOOP-1090 | In SortValidator, the check for whether a file belongs to sort-input or sort-output dir is weak | Major | . | Devaraj Das | Arun C Murthy
HADOOP-1081 | JAVA_PLATFORM with spaces (i.e. Mac OS X-ppc-32) breaks bin/hadoop script | Major | scripts | Andrzej Bialecki |
HADOOP-1156 | NullPointerException in MiniDFSCluster | Major | . | Konstantin Shvachko | Hairong Kuang
HADOOP-1163 | Ganglia metrics reporting is misconfigured | Minor | metrics | Michael Bieniosek |
HADOOP-1187 | DFS Scalability: avoid scanning entire list of datanodes in getAdditionalBlocks | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1151 | streaming PipeMapRed prints system info to stderr | Trivial | . | Koji Noguchi | Koji Noguchi
HADOOP-1203 | UpgradeUtilities should use MiniDFSCluster to start and stop NameNode/DataNodes | Major | test | Nigel Daley | Nigel Daley
HADOOP-1149 | DFS Scalability: high cpu usage in addStoredBlock | Major | . | dhruba borthakur | Raghu Angadi
HADOOP-1073 | DFS Scalability: high CPU usage in choosing replication targets and file open | Major | . | dhruba borthakur | Hairong Kuang
HADOOP-1218 | In TaskTracker the access to RunningJob object is not synchronized in one place | Major | . | Devaraj Das | Devaraj Das
HADOOP-1219 | Spurious progress messages should be discarded after a task is done | Major | . | Devaraj Das | Devaraj Das
HADOOP-1198 | ipc.client.timeout of 2000ms for test cases seems too small; causes too many timeouts and leads to hung test cases | Major | test | Arun C Murthy | Arun C Murthy
HADOOP-1211 | Remove deprecated constructor and unused static members in DataNode class | Major | . | Konstantin Shvachko | Konstantin Shvachko
HADOOP-1136 | exception in UnderReplicatedBlocks:add when ther are more replicas of a block than required | Major | . | dhruba borthakur | Hairong Kuang
HADOOP-1001 | the output of the map is not type checked against the specified types | Major | . | Owen O’Malley | Tahir Hashmi
HADOOP-1189 | Still seeing some unexpected ‘No space left on device’ exceptions | Major | . | Raghu Angadi | Raghu Angadi
HADOOP-1204 | Re-factor InputFormat/RecordReader related classes | Major | . | Runping Qi | Runping Qi
HADOOP-1114 | bin/hadoop script clobbers CLASSPATH | Minor | scripts | Michael Bieniosek | Doug Cutting
HADOOP-1238 | maps_running metric is only updated at the end of the task | Minor | metrics | Michael Bieniosek | David Bowen
HADOOP-1093 | NNBench generates millions of NotReplicatedYetException in Namenode log | Major | . | Nigel Daley | dhruba borthakur
HADOOP-1239 | Classes in src/test/testjar need package name | Trivial | test | Jim Kellerman | Jim Kellerman
HADOOP-1243 | ClientProtocol.versionID should be 11 | Major | . | Konstantin Shvachko | dhruba borthakur
HADOOP-1241 | Null PointerException in processReport when namenode is restarted | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1244 | stop-dfs.sh incorrectly specifies slaves file for stopping datanode | Minor | . | Michael Bieniosek | dhruba borthakur
HADOOP-1253 | ConcurrentModificationException and NPE in JobControl | Minor | . | Johan Oskarsson | Johan Oskarsson
HADOOP-1256 | Dfs image loading and edits loading creates multiple instances of DatanodeDescriptor for the same datanode | Major | . | Hairong Kuang | Hairong Kuang
HADOOP-1258 | TestCheckpoint test case doesn’t wait for MiniDFSCluster to be active | Trivial | test | Nigel Daley | Nigel Daley
HADOOP-1154 | streaming hang. (PipeMapRed$MROutputThread gone) | Major | . | Koji Noguchi | Koji Noguchi
HADOOP-1275 | job notification property in hadoop-default.xml is misspelled | Trivial | . | Alejandro Abdelnur |
HADOOP-1152 | Reduce task hang failing in MapOutputCopier.copyOutput | Major | . | Koji Noguchi | Tahir Hashmi
HADOOP-1050 | Do not count lost tasktracker against the job | Major | . | Arun C Murthy | Arun C Murthy
HADOOP-1271 | The StreamBaseRecordReader is unable to log record data that’s not UTF-8 | Minor | . | Gautam Kowshik | Arun C Murthy
HADOOP-1262 | file corruption detected because dfs client does not use replica blocks for checksum file | Major | . | dhruba borthakur | Hairong Kuang
HADOOP-1279 | list of completed jobs purges jobs based on submission not on completion age | Major | . | Alejandro Abdelnur | Arun C Murthy
HADOOP-1176 | Reduce hang on huge map output | Major | . | Hairong Kuang | Arun C Murthy
HADOOP-1293 | stderr from streaming skipped after first 20 lines. | Minor | . | Koji Noguchi | Koji Noguchi
HADOOP-1297 | datanode sending block reports to namenode once every second | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1294 | Fix unchecked warnings in main Hadoop code under Java 6. | Major | test | Tom White | Tom White
HADOOP-1299 | Once RPC.stopClient has been called, RPC can not be used again | Minor | ipc | stack | stack
HADOOP-1278 | Fix the per-job tasktracker ‘blacklist’ | Major | . | Arun C Murthy | Arun C Murthy
HADOOP-1272 | Extract InnerClasses from FSNamesystem into separate classes | Major | . | dhruba borthakur | dhruba borthakur
HADOOP-1061 | S3 listSubPaths bug | Critical | fs | Mike Smith |
HADOOP-1312 | heartbeat monitor thread goes away | Blocker | . | dhruba borthakur | dhruba borthakur
HADOOP-1322 | Tasktracker blacklist leads to hung jobs in single-node cluster | Critical | . | Arun C Murthy | Arun C Murthy
HADOOP-1184 | Decommission fails if a block that needs replication has only one replica | Major | . | dhruba borthakur |
HADOOP-1224 | “Browse the filesystem” link pointing to a dead data-node | Major | . | Konstantin Shvachko | Enis Soztutar
HADOOP-1200 | Datanode should periodically do a disk check | Blocker | . | Hairong Kuang | Hairong Kuang
HADOOP-1252 | Disk problems should be handled better by the MR framework | Major | . | Devaraj Das | Devaraj Das
HADOOP-1310 | Fix unchecked warnings in aggregate code | Major | . | Tom White | Tom White
HADOOP-1255 | Name-node falls into infinite loop trying to remove a dead node. | Blocker | . | Konstantin Shvachko | Hairong Kuang
HADOOP-1160 | DistributedFileSystem doesn’t close the RawDistributedFileSystem on close. | Blocker | . | Owen O’Malley | Hairong Kuang
HADOOP-1350 | Shuffle started taking a very long time after the HADOOP-1176 fix | Blocker | . | Devaraj Das | Devaraj Das
HADOOP-1345 | Checksum object does not get restored to the old state in retries when handle ChecksumException | Blocker | . | Hairong Kuang | Hairong Kuang
HADOOP-1205 | The open method of FSNamesystem should be synchronized | Blocker | . | Hairong Kuang | Hairong Kuang
HADOOP-1353 | Null pointer dereference of nodeInfo in FSNamesystem.removeDatanode(DatanodeID) | Blocker | . | Nigel Daley | dhruba borthakur
HADOOP-1354 | Null pointer dereference of paths in FsShell.dus(String) | Blocker | fs | Nigel Daley | Hairong Kuang
HADOOP-1358 | seek call ignores result of skipBytes(int) | Blocker | . | Nigel Daley | Hairong Kuang
HADOOP-1356 | ValueHistogram.addNextValue(Object) ignores return value of String.substring(int, int) | Blocker | . | Nigel Daley | Runping Qi
HADOOP-1363 | waitForCompletion() calls Thread.sleep() with a lock held | Blocker | . | Nigel Daley | Owen O’Malley
HADOOP-1368 | Inconsistent synchronization of 3 fields in JobInProgress.java | Blocker | . | Nigel Daley | Owen O’Malley
HADOOP-1369 | Inconsistent synchronization of TaskTracker fields | Blocker | . | Nigel Daley | Owen O’Malley
HADOOP-1361 | seek calls in 3 io classes ignore result of skipBytes(int) | Blocker | io | Nigel Daley | Hairong Kuang
HADOOP-1388 | Possible Null Pointer Dereference in taskdetails.jsp | Major | . | Devaraj Das | Devaraj Das
HADOOP-1385 | MD5Hash has a bad hash function | Major | io | Owen O’Malley | Owen O’Malley
HADOOP-1386 | The constructor of Path should not take an empty string as a parameter | Blocker | . | Hairong Kuang | Hairong Kuang
HADOOP-1407 | Failed tasks not killing job | Blocker | . | Nigel Daley | Arun C Murthy
HADOOP-1427 | Typo in GzipCodec.createInputStream - bufferSize | Blocker | io | Espen Amble Kolstad | Espen Amble Kolstad
HADOOP-1435 | FileSystem.globPaths should not create a Path from an empty string | Blocker | fs | Hairong Kuang | Hairong Kuang
HADOOP-1411 | AlreadyBeingCreatedException from task retries | Blocker | . | Nigel Daley | Hairong Kuang
HADOOP-1242 | dfs upgrade/downgrade problems | Blocker | . | Owen O’Malley | Konstantin Shvachko
HADOOP-1332 | Sporadic unit test failures (TestMiniMRClasspath, TestMiniMRLocalFS, TestMiniMRDFSCaching) | Blocker | . | Nigel Daley | Arun C Murthy
HADOOP-1431 | Map tasks can’t timeout for failing to call progress | Blocker | . | Owen O’Malley | Arun C Murthy
HADOOP-1452 | map output transfers of more than 2^31 bytes output are failing | Blocker | . | Christian Kunz | Owen O’Malley