| Package | Description | 
|---|---|
| org.apache.hadoop.fs | Implementations of  AbstractFileSystemfor hdfs
    over rpc and hdfs over web. | 
| org.apache.hadoop.fs.adl | Supporting classes for metrics instrumentation. | 
| org.apache.hadoop.fs.azure | 
A distributed implementation of  FileSystemfor reading and writing files on
Azure Block Storage. | 
| org.apache.hadoop.fs.azurebfs.commit | Support for manifest committer. | 
| org.apache.hadoop.fs.ftp | |
| org.apache.hadoop.fs.s3native | 
A distributed implementation of  FileSystemfor reading and writing files on
Amazon S3. | 
| org.apache.hadoop.fs.viewfs | ViewFileSystem and ViewFileSystemOverloadScheme classes. | 
| org.apache.hadoop.io.serializer | 
This package provides a mechanism for using different serialization frameworks
in Hadoop. | 
| org.apache.hadoop.io.serializer.avro | 
This package provides Avro serialization in Hadoop. | 
| org.apache.hadoop.mapred | |
| org.apache.hadoop.mapred.pipes | |
| org.apache.hadoop.mapreduce.lib.output | |
| org.apache.hadoop.mapreduce.lib.output.committer.manifest | Intermediate manifest committer. | 
| org.apache.hadoop.mapreduce.lib.partition | |
| org.apache.hadoop.mapreduce.tools | |
| org.apache.hadoop.tools | Command-line tools for MapReduce. | 
| org.apache.hadoop.tools.dynamometer | The Dynamometer tool is used to stress test the HDFS NameNode by setting
 up a realistic environment consistent of fake DataNodes and a real NameNode
 with a real FS namesystem and near-real user workload (RPCs). | 
| org.apache.hadoop.yarn.client.cli | |
| org.apache.hadoop.yarn.util | Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | ChecksumFileSystemAbstract Checksumed FileSystem. | 
| class  | FileSystemAn abstract base class for a fairly generic filesystem. | 
| class  | FilterFileSystemA  FilterFileSystemcontains
 some other file system, which it uses as
 its  basic file system, possibly transforming
 the data along the way or providing  additional
 functionality. | 
| class  | LocalFileSystemImplement the FileSystem API for the checksumed local filesystem. | 
| class  | RawLocalFileSystemImplement the FileSystem API for the raw local filesystem. | 
| class  | TrashProvides a trash facility which supports pluggable Trash policies. | 
| class  | TrashPolicyThis interface is used for implementing different Trash policies. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | AdlFileSystemA FileSystem to access Azure Data Lake Store. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | NativeAzureFileSystemA  FileSystemfor reading and writing files stored on Windows Azure. | 
| class  | WasbFsckAn fsck tool implementation for WASB that does various admin/cleanup/recovery
 tasks on the WASB file system. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | AzureManifestCommitterFactoryA Committer for the manifest committer which performs all bindings needed
 to work best with abfs. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | FTPFileSystem
 A  FileSystembacked by an FTP client provided by Apache Commons Net. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | NativeS3FileSystemDeprecated. 
 Replaced by the S3A client. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | ViewFileSystemViewFileSystem (extends the FileSystem interface) implements a client-side
 mount table. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | WritableSerializationA  SerializationforWritables that delegates toWritable.write(java.io.DataOutput)andWritable.readFields(java.io.DataInput). | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | AvroReflectSerializationSerialization for Avro Reflect classes. | 
| class  | AvroSerialization<T>Base class for providing serialization to Avro types. | 
| class  | AvroSpecificSerializationSerialization for Avro Specific classes. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | JobClientJobClientis the primary interface for the user-job to interact
 with the cluster. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | SubmitterThe main entry point and job submitter. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | PathOutputCommitterFactoryA factory for committers implementing the  PathOutputCommittermethods, and so can be used fromFileOutputFormat. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | ManifestCommitterFactoryThis is the committer factory to register as the source of committers
 for the job/filesystem schema. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | InputSampler<K,V>Utility for collecting samples and writing a partition file for
  TotalOrderPartitioner. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | CLIInterprets the map reduce cli options | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | DistCpDistCp is the main driver-class for DistCpV2. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | ClientClient for submitting a Dynamometer YARN application, and optionally, a
 workload MapReduce job. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | LogsCLI | 
| class  | SchedConfCLICLI for modifying scheduler configuration. | 
| Modifier and Type | Class and Description | 
|---|---|
| class  | ResourceCalculatorProcessTreeInterface class to obtain process resource usage
 NOTE: This class should not be used by external users, but only by external
 developers to extend and include their own process-tree implementation, 
 especially for platforms other than Linux and Windows. | 
Copyright © 2025 Apache Software Foundation. All rights reserved.