##### 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 1.3.0 - Unreleased (as of 2018-09-02)

### INCOMPATIBLE CHANGES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
MAPREDUCE-5777 | Support utf-8 text with BOM (byte order marker) | Major | . | bc Wong | zhihai xu

### IMPROVEMENTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
MAPREDUCE-2351 | mapred.job.tracker.history.completed.location should support an arbitrary filesystem URI | Major | . | Tom White | Tom White
HADOOP-9450 | HADOOP_USER_CLASSPATH_FIRST is not honored; CLASSPATH is PREpended instead of APpended | Major | scripts | Mitch Wyle | Harsh J
HDFS-4521 | invalid network topologies should not be cached | Minor | . | Colin P. McCabe | Colin P. McCabe
HADOOP-8873 | Port HADOOP-8175 (Add mkdir -p flag) to branch-1 | Major | . | Eli Collins | Akira Ajisaka
HDFS-4903 | Print trash configuration and trash emptier state in namenode log | Minor | namenode | Suresh Srinivas | Arpit Agarwal
MAPREDUCE-5406 | Improve logging around Task Tracker exiting with JVM manager inconsistent state | Major | tasktracker | Chelsey Chang | Chelsey Chang
MAPREDUCE-5408 | CLONE - The logging level of the tasks should be configurable by the job | Major | . | Owen O’Malley | Arun C Murthy
MAPREDUCE-5367 | Local jobs all use same local working directory | Major | . | Sandy Ryza | Sandy Ryza
HDFS-4963 | Improve multihoming support in namenode | Major | namenode | Arpit Agarwal | Arpit Agarwal
HADOOP-9855 | Backport HADOOP-6578 to branch-1 | Major | . | James Kinley | James Kinley
HDFS-5038 | Backport several branch-2 APIs to branch-1 | Minor | . | Jing Zhao | Jing Zhao
HDFS-5367 | Restoring namenode storage locks namenode due to unnecessary fsimage write | Major | . | yunjiong zhao | yunjiong zhao
MAPREDUCE-5457 | Add a KeyOnlyTextOutputReader to enable streaming to write out text files without separators | Major | . | Sandy Ryza | Sandy Ryza
MAPREDUCE-5609 | Add debug log message when sending job end notification | Major | . | Robert Kanter | Robert Kanter
MAPREDUCE-3310 | Custom grouping comparator cannot be set for Combiners | Major | client | Mathias Herberts | Alejandro Abdelnur
MAPREDUCE-5651 | Backport Fair Scheduler queue placement policies to branch-1 | Major | scheduler | Sandy Ryza | Ted Malaska
MAPREDUCE-5712 | Backport Fair Scheduler pool placement by secondary group | Major | scheduler | Theodore michael Malaska | Theodore michael Malaska
HADOOP-10614 | CBZip2InputStream is not threadsafe | Major | . | Xiangrui Meng | Xiangrui Meng
MAPREDUCE-6088 | TestTokenCache tests should use their own JobConf instances | Major | mrv1, test | zhihai xu | zhihai xu
HDFS-7312 | Update DistCp v1 to optionally not use tmp location (branch-1 only) | Minor | tools | Joseph Prosser | Joseph Prosser

### BUG FIXES:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-7140 | IPC Reader threads do not stop when server stops | Critical | . | Todd Lipcon | Todd Lipcon
HDFS-2264 | NamenodeProtocol has the wrong value for clientPrincipal in KerberosInfo annotation | Major | namenode | Aaron T. Myers | Aaron T. Myers
MAPREDUCE-5046 | backport MAPREDUCE-1423 to mapred.lib.CombineFileInputFormat | Major | client | Sangjin Lee |
MAPREDUCE-5047 | keep.failed.task.files=true causes job failure on secure clusters | Major | task, tasktracker | Sandy Ryza | Sandy Ryza
MAPREDUCE-5070 | TestClusterStatus.testClusterMetrics fails on JDK7 | Major | test | Sandy Ryza | Sandy Ryza
MAPREDUCE-5072 | TestDelegationTokenRenewal.testDTRenewal fails in MR1 on jdk7 | Major | test | Sandy Ryza | Sandy Ryza
MAPREDUCE-5073 | TestJobStatusPersistency.testPersistency fails on JDK7 | Major | test | Sandy Ryza | Sandy Ryza
HDFS-4622 | Remove redundant synchronized from FSNamesystem#rollEditLog in branch-1 | Trivial | . | Jing Zhao | Jing Zhao
MAPREDUCE-2817 | MiniRMCluster hardcodes ‘mapred.local.dir’ configuration to ‘build/test/mapred/local’ | Minor | test | Alejandro Abdelnur | Robert Kanter
MAPREDUCE-5133 | TestSubmitJob.testSecureJobExecution is flaky due to job dir deletion race | Major | test | Sandy Ryza | Sandy Ryza
MAPREDUCE-5218 | Annotate (comment) internal classes as Private | Minor | . | Karthik Kambatla | Karthik Kambatla
MAPREDUCE-5217 | DistCp fails when launched by Oozie in a secure cluster | Major | distcp, security | Venkat Ranganathan | Venkat Ranganathan
MAPREDUCE-5095 | TestShuffleExceptionCount#testCheckException fails occasionally with JDK7 | Major | . | Arpit Agarwal | Arpit Agarwal
MAPREDUCE-5250 | Searching for ‘;’ in JobTracker History throws ArrayOutOfBoundException | Minor | . | Karthik Kambatla | Karthik Kambatla
HDFS-4944 | WebHDFS cannot create a file path containing characters that must be URI-encoded, such as space. | Major | webhdfs | Chris Nauroth | Chris Nauroth
HADOOP-9678 | TestRPC#testStopsAllThreads intermittently fails on Windows | Major | . | Ivan Mitic | Ivan Mitic
HADOOP-9307 | BufferedFSInputStream.read returns wrong results after certain seeks | Major | fs | Todd Lipcon | Todd Lipcon
HDFS-5003 | TestNNThroughputBenchmark failed caused by existing directories | Minor | test | Xi Fang | Xi Fang
MAPREDUCE-5405 | Job recovery can fail if task log directory symlink from prior run still exists | Major | mrv1 | Chris Nauroth | Chris Nauroth
MAPREDUCE-5288 | ResourceEstimator#getEstimatedTotalMapOutputSize suffers from divide by zero issues | Major | mrv1 | Harsh J | Karthik Kambatla
HADOOP-9507 | LocalFileSystem rename() is broken in some cases when destination exists | Minor | fs | Mostafa Elhemali | Chris Nauroth
MAPREDUCE-4366 | mapred metrics shows negative count of waiting maps and reduces | Major | jobtracker | Thomas Graves | Sandy Ryza
HADOOP-9768 | chown and chgrp reject users and groups with spaces on platforms where spaces are otherwise acceptable | Major | fs | Chris Nauroth | Chris Nauroth
HADOOP-9801 | Configuration#writeXml uses platform defaulting encoding, which may mishandle multi-byte characters. | Major | conf | Chris Nauroth | Chris Nauroth
HDFS-4898 | BlockPlacementPolicyWithNodeGroup.chooseRemoteRack() fails to properly fallback to local rack | Minor | namenode | Eric Sirianni | Tsz Wo Nicholas Sze
HDFS-5211 | Race condition between DistributedFileSystem#close and FileSystem#close can cause return of a closed DistributedFileSystem instance from the FileSystem cache. | Major | hdfs-client | Chris Nauroth | Chris Nauroth
MAPREDUCE-5508 | JobTracker memory leak caused by unreleased FileSystem objects in JobInProgress#cleanupJob | Critical | jobtracker | Xi Fang | Xi Fang
HDFS-5245 | shouldRetry() in WebHDFSFileSystem generates excessive warnings | Minor | webhdfs | Haohui Mai | Haohui Mai
HADOOP-10009 | Backport HADOOP-7808 to branch-1 | Major | . | Haohui Mai | Haohui Mai
MAPREDUCE-5569 | FloatSplitter is not generating correct splits | Major | . | Nathan Roberts | Nathan Roberts
MAPREDUCE-5512 | TaskTracker hung after failed reconnect to the JobTracker | Major | tasktracker | Ivan Mitic | Ivan Mitic
HDFS-4794 | Browsing filesystem via webui throws kerberos exception when NN service RPC is enabled in a secure cluster | Major | security | Benoy Antony | Benoy Antony
HADOOP-10142 | Avoid groups lookup for unprivileged users such as “dr.who” | Major | . | Vinayakumar B | Vinayakumar B
HADOOP-10090 | Jobtracker metrics not updated properly after execution of a mapreduce job | Major | metrics | Ivan Mitic | Ivan Mitic
MAPREDUCE-5702 | TaskLogServlet#printTaskLog has spurious HTML closing tags | Trivial | task | Karthik Kambatla | Robert Kanter
MAPREDUCE-5698 | Backport MAPREDUCE-1285 to branch-1 | Major | . | Yongjun Zhang | Yongjun Zhang
HDFS-5685 | DistCp will fail to copy with -delete switch | Major | hdfs-client | Yongjun Zhang | Yongjun Zhang
MAPREDUCE-5710 | Backport MAPREDUCE-1305 to branch-1 | Major | . | Yongjun Zhang | Yongjun Zhang
HDFS-5944 | LeaseManager:findLeaseWithPrefixPath can’t handle path like /a/b/ right and cause SecondaryNameNode failed do checkpoint | Major | namenode | yunjiong zhao | yunjiong zhao
HDFS-5516 | WebHDFS does not require user name when anonymous http requests are disallowed. | Major | webhdfs | Chris Nauroth | Miodrag Radulovic
MAPREDUCE-5808 | Port output replication factor configurable for terasort to Hadoop 1.x | Minor | examples | Chuan Liu | Chuan Liu
MAPREDUCE-5822 | FairScheduler does not preempt due to fairshare-starvation when fairshare is 1 | Major | scheduler | Anubhav Dhoot | Anubhav Dhoot
HDFS-6141 | WebHdfsFileSystem#toUrl does not perform character escaping. | Major | webhdfs | Chris Nauroth | Chris Nauroth
HADOOP-10562 | Namenode exits on exception without printing stack trace in AbstractDelegationTokenSecretManager | Critical | . | Suresh Srinivas | Suresh Srinivas
MAPREDUCE-5877 | Inconsistency between JT/TT for tasks taking a long time to launch | Critical | jobtracker, tasktracker | Karthik Kambatla | Karthik Kambatla
MAPREDUCE-5979 | FairScheduler: zero weight can cause sort failures | Major | scheduler | Anubhav Dhoot | Anubhav Dhoot
MAPREDUCE-5966 | MR1 FairScheduler use of custom weight adjuster is not thread safe for comparisons | Major | scheduler | Anubhav Dhoot | Anubhav Dhoot
MAPREDUCE-5968 | Work directory is not deleted when downloadCacheObject throws IOException | Major | mrv1 | zhihai xu | zhihai xu
HDFS-6822 | In branch-1, Namenode and datanode fails to replace “_HOST” to hostname for hadoop.http.authentication.kerberos.principal | Major | security | Jing Zhao | Jing Zhao
MAPREDUCE-6012 | DBInputSplit creates invalid ranges on Oracle | Major | . | Julien Serdaru | Wei Yan
HADOOP-11035 | distcp on mr1(branch-1) fails with NPE using a short relative source path. | Major | tools | zhihai xu | zhihai xu
MAPREDUCE-6009 | Map-only job with new-api runs wrong OutputCommitter when cleanup scheduled in a reduce slot | Blocker | client, job submission | Gera Shegalov | Gera Shegalov
MAPREDUCE-6147 | Support mapreduce.input.fileinputformat.split.maxsize | Minor | mrv1 | zhihai xu | zhihai xu
MAPREDUCE-6170 | TestUlimit failure on JDK8 | Major | contrib/streaming | bc Wong | bc Wong
HDFS-7503 | Namenode restart after large deletions can cause slow processReport (due to logging) | Major | namenode | Arpit Agarwal | Arpit Agarwal
MAPREDUCE-6196 | Fix BigDecimal ArithmeticException in PiEstimator | Minor | . | Ray Chiang | Ray Chiang
MAPREDUCE-6198 | NPE from JobTracker#resolveAndAddToTopology in MR1 cause initJob and heartbeat failure. | Major | mrv1 | zhihai xu | zhihai xu
MAPREDUCE-5272 | A Minor Error in Javadoc of TestMRWithDistributedCache in Branch-1 | Trivial | test | Zhijie Shen | Zhijie Shen
MAPREDUCE-5556 | mapred docs have incorrect classpath | Trivial | . | Allen Wittenauer | Harsh J
MAPREDUCE-5660 | Log info about possible thrashing (when using memory-based scheduling in Capacity Scheduler) is not printed | Trivial | capacity-sched, mrv1, tasktracker | Adam Kawa | Adam Kawa
MAPREDUCE-5183 | In, TaskTracker#reportProgress logging of 0.0-1.0 progress is followed by percent sign | Minor | mrv1, tasktracker | Sandy Ryza | Niranjan Singh
HDFS-6649 | Documentation for setrep is wrong | Trivial | documentation | Alexander Fahlke | Akira Ajisaka
MAPREDUCE-6076 | Zero map split input length combine with none zero map split input length may cause MR1 job hung sometimes. | Major | mrv1 | zhihai xu | zhihai xu

### TESTS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
HADOOP-9624 | TestFSMainOperationsLocalFileSystem failed when the Hadoop test root path has “X” in its name | Minor | test | Xi Fang | Xi Fang

### SUB-TASKS:

JIRA | Summary | Priority | Component | Reporter | Contributor
--- | --- | --- | --- | --- | ---
MAPREDUCE-4049 | plugin for generic shuffle service | Major | performance, task, tasktracker | Avner BenHanoch | Avner BenHanoch
HADOOP-9573 | Fix test-patch script to work with the enhanced PreCommit-Admin script. | Major | build | Giridharan Kesavan | Giridharan Kesavan