Apache Hadoop 3.5.0 – Apache Hadoop 0.22.1 Release Notes

##### 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
- Fair Call Queue
- Native Libraries
- Proxy User
- Rack Awareness
- Secure Mode
- Service Level Authorization
- HTTP Authentication
- Credential Provider API
- Hadoop KMS
- Tracing
- Unix Shell Guide
- Registry
- Async Profiler

##### 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
- 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
- Running Applications in runC Containers
- Using CGroups
- Secure Containers
- 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

##### Hadoop Compatible File Systems

- Aliyun OSS
- Amazon S3
- Azure Blob Storage
- Azure Data Lake Storage
- Tencent COS
- Huaweicloud OBS
- VolcanoEngine TOS

##### Auth

- Overview
- Examples
- Configuration
- Building

##### Tools

- Hadoop Streaming
- Hadoop Archives
- Hadoop Archive Logs
- DistCp
- HDFS Federation Balance
- GridMix
- Rumen
- Resource Estimator Service
- Scheduler Load Simulator
- Hadoop Benchmarking
- Dynamometer

##### 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 0.22.1 Release Notes

These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.

- HADOOP-6995 | Minor | Allow wildcards to be used in ProxyUsers configurations

When configuring proxy users and hosts, the special wildcard value “*” may be specified to match any host or any user.

- HADOOP-7119 | Major | add Kerberos HTTP SPNEGO authentication support to Hadoop JT/NN/DN/TT web-consoles

Adding support for Kerberos HTTP SPNEGO authentication to the Hadoop web-consoles

- HDFS-2246 | Major | Shortcut a local client reads to a Datanodes files directly

1. New configurations a. dfs.block.local-path-access.user is the key in datanode configuration to specify the user allowed to do short circuit read. b. dfs.client.read.shortcircuit is the key to enable short circuit read at the client side configuration. c. dfs.client.read.shortcircuit.skip.checksum is the key to bypass checksum check at the client side.
2. By default none of the above are enabled and short circuit read will not kick in.
3. If security is on, the feature can be used only for user that has kerberos credentials at the client, therefore map reduce tasks cannot benefit from it in general.

- MAPREDUCE-3725 | Major | Hadoop 22 hadoop job -list returns user name as NULL

Submitting the patch after setting the user name at the client side

- HADOOP-6453 | Minor | Hadoop wrapper script shouldn’t ignore an existing JAVA_LIBRARY_PATH

WARNING: No release note provided for this change.