org.apache.hadoop.util (Apache Hadoop Main 3.5.0 API)
Description: declaration: package: org.apache.hadoop.util

# Package org.apache.hadoop.util

package org.apache.hadoop.util
Common utilities.

- Related Packages
  Package
  Description
  org.apache.hadoop
  org.apache.hadoop.util.bloom
  org.apache.hadoop.util.curator
  This package provides utilities to interact with Curator ZooKeeper.
  org.apache.hadoop.util.functional
  Support for functional programming within the Hadoop APIs.
  org.apache.hadoop.util.hash
- Class
  Description
  ApplicationClassLoader
  A `URLClassLoader` for application isolation.
  org.apache.hadoop.util.AsyncDiskService
  org.apache.hadoop.util.AutoCloseableLock
  This is a wrap class of a ReentrantLock.
  org.apache.hadoop.util.BasicDiskValidator
  BasicDiskValidator is a wrapper around `DiskChecker`.
  org.apache.hadoop.util.BlockingThreadPoolExecutorService
  This ExecutorService blocks the submission of new tasks when its queue is already full by using a semaphore.
  org.apache.hadoop.util.CacheableIPList
  CacheableIPList loads a list of subnets from a file.
  org.apache.hadoop.util.ChunkedArrayList<T>
  Simplified List implementation which stores elements as a list of chunks, each chunk having a maximum size.
  org.apache.hadoop.util.Classpath
  Command-line utility for getting the full classpath needed to launch a Hadoop client application.
  org.apache.hadoop.util.ClassUtil
  org.apache.hadoop.util.CleanerUtil
  sun.misc.Cleaner has moved in OpenJDK 9 and sun.misc.Unsafe#invokeCleaner(ByteBuffer) is the replacement.
  org.apache.hadoop.util.CleanerUtil.BufferCleaner
  Pass in an implementation of this interface to cleanup ByteBuffers.
  org.apache.hadoop.util.CloseableReferenceCount
  A closeable object that maintains a reference count.
  org.apache.hadoop.util.CombinedIPList
  Util class to stores ips/hosts/subnets.
  org.apache.hadoop.util.CombinedIPWhiteList
  org.apache.hadoop.util.ComparableVersion
  Generic implementation of version comparison.
  org.apache.hadoop.util.ConfigurationHelper
  Configuration Helper class to provide advanced configuration parsing.
  org.apache.hadoop.util.ConfTest
  This class validates configuration XML files in ${HADOOP_CONF_DIR} or specified ones.
  org.apache.hadoop.util.CpuTimeTracker
  Utility for sampling and computing CPU usage.
  org.apache.hadoop.util.CrcComposer
  Encapsulates logic for composing multiple CRCs into one or more combined CRCs corresponding to concatenated underlying data ranges.
  org.apache.hadoop.util.CrcUtil
  This class provides utilities for working with CRCs.
  org.apache.hadoop.util.Daemon
  A thread that has called `Thread.setDaemon(boolean)` with true.
  org.apache.hadoop.util.Daemon.DaemonFactory
  Provide a factory for named daemon threads, for use in ExecutorServices constructors
  org.apache.hadoop.util.DataChecksum
  This class provides interface and utilities for processing checksums for DFS data transfers.
  DataChecksum.Type
  The checksum types
  org.apache.hadoop.util.DirectBufferPool
  A simple class for pooling direct ByteBuffers.
  org.apache.hadoop.util.DiskChecker
  Class that provides utility functions for checking disk problem
  org.apache.hadoop.util.DiskChecker.DiskErrorException
  org.apache.hadoop.util.DiskChecker.DiskOutOfSpaceException
  org.apache.hadoop.util.DiskValidator
  A interface for disk validators.
  org.apache.hadoop.util.DiskValidatorFactory
  The factory class to create instance of `DiskValidator`.
  DurationInfo
  A duration with logging of final state at info or debug in the `close()` call.
  org.apache.hadoop.util.ExitCodeProvider
  Get the exit code of an exception.
  org.apache.hadoop.util.ExitUtil
  Facilitates hooking process termination for tests, debugging and embedding.
  org.apache.hadoop.util.ExitUtil.ExitException
  An exception raised when a call to `ExitUtil.terminate(int)` was called and system exits were blocked.
  org.apache.hadoop.util.ExitUtil.HaltException
  An exception raised when a call to `ExitUtil.terminate(int)` was called and system halts were blocked.
  org.apache.hadoop.util.FastNumberFormat
  Fast thread-safe version of NumberFormat
  org.apache.hadoop.util.FileBasedIPList
  FileBasedIPList loads a list of subnets in CIDR format and ip addresses from a file.
  org.apache.hadoop.util.FindClass
  This entry point exists for diagnosing classloader problems: is a class or resource present -and if so, where?
  org.apache.hadoop.util.GcTimeMonitor
  This class monitors the percentage of time the JVM is paused in GC within the specified observation window, say 1 minute.
  org.apache.hadoop.util.GcTimeMonitor.Builder
  org.apache.hadoop.util.GcTimeMonitor.GcData
  Encapsulates data about GC pauses measured at the specific timestamp.
  org.apache.hadoop.util.GcTimeMonitor.GcTimeAlertHandler
  The user can provide an instance of a class implementing this interface when initializing a GcTimeMonitor to receive alerts when GC time percentage exceeds the specified threshold.
  org.apache.hadoop.util.GenericOptionsParser
  `GenericOptionsParser` is a utility to parse command line arguments generic to the Hadoop framework.
  org.apache.hadoop.util.GenericsUtil
  Contains utility methods for dealing with Java Generics.
  org.apache.hadoop.util.GSet<K,E extends K>
  A `GSet` is set, which supports the `GSet.get(Object)` operation.
  org.apache.hadoop.util.GSetByHashMap<K,E extends K>
  A `GSet` implementation by `HashMap`.
  org.apache.hadoop.util.HeapSort
  An implementation of the core algorithm of HeapSort.
  org.apache.hadoop.util.HostsFileReader
  org.apache.hadoop.util.HostsFileReader.HostDetails
  An atomic view of the included and excluded hosts
  org.apache.hadoop.util.HttpExceptionUtils
  HTTP utility class to help propagate server side exception to the client over HTTP as a JSON payload.
  org.apache.hadoop.util.IdentityHashStore<K,V>
  The IdentityHashStore stores (key, value) mappings in an array.
  org.apache.hadoop.util.IdentityHashStore.Visitor<K,V>
  org.apache.hadoop.util.IdGenerator
  Generic ID generator used for generating various types of number sequences.
  org.apache.hadoop.util.IndexedSortable
  Interface for collections capable of being sorted by `IndexedSorter` algorithms.
  org.apache.hadoop.util.IndexedSorter
  Interface for sort algorithms accepting `IndexedSortable` items.
  org.apache.hadoop.util.InstrumentedLock
  This is a debugging class that can be used by callers to track whether a specific lock is being held for too long and periodically log a warning and stack trace, if so.
  org.apache.hadoop.util.InstrumentedLock.SuppressedSnapshot
  Immutable class to capture a snapshot of suppressed log message stats.
  org.apache.hadoop.util.InstrumentedReadLock
  This is a wrap class of a `ReadLock`.
  org.apache.hadoop.util.InstrumentedReadWriteLock
  This is a wrap class of a `ReentrantReadWriteLock`.
  org.apache.hadoop.util.InstrumentedWriteLock
  This is a wrap class of a `WriteLock`.
  org.apache.hadoop.util.IntrusiveCollection<E extends org.apache.hadoop.util.IntrusiveCollection.Element>
  Implements an intrusive doubly-linked list.
  org.apache.hadoop.util.IntrusiveCollection.Element
  An element contained in this list.
  org.apache.hadoop.util.InvalidChecksumSizeException
  Thrown when bytesPerChecksun field in the meta file is less than or equal to 0 or type is invalid.
  IPList
  org.apache.hadoop.util.JsonSerialization<T>
  Support for marshalling objects to and from JSON.
  org.apache.hadoop.util.JvmPauseMonitor
  Class which sets up a simple thread which runs in a loop sleeping for a short interval of time.
  org.apache.hadoop.util.KMSUtil
  Utils for KMS.
  org.apache.hadoop.util.LambdaUtils
  Lambda-expression utilities be they generic or specific to Hadoop datatypes.
  org.apache.hadoop.util.LightWeightCache<K,E extends K>
  A low memory footprint Cache which extends `LightWeightGSet`.
  org.apache.hadoop.util.LightWeightCache.Entry
  Entries of `LightWeightCache`.
  org.apache.hadoop.util.LightWeightGSet<K,E extends K>
  A low memory footprint `GSet` implementation, which uses an array for storing the elements and linked lists for collision resolution.
  org.apache.hadoop.util.LightWeightGSet.LinkedElement
  Elements of `LightWeightGSet`.
  org.apache.hadoop.util.LightWeightResizableGSet<K,E extends K>
  A low memory footprint `GSet` implementation, which uses an array for storing the elements and linked lists for collision resolution.
  org.apache.hadoop.util.LimitInputStream
  Copied from guava source code v15 (LimitedInputStream) Guava deprecated LimitInputStream in v14 and removed it in v15.
  org.apache.hadoop.util.LineReader
  A class that provides a line reader from an input stream.
  org.apache.hadoop.util.Lists
  Static utility methods pertaining to `List` instances.
  org.apache.hadoop.util.MachineList
  Container class which holds a list of ip/host addresses and answers membership queries.
  org.apache.hadoop.util.MachineList.InetAddressFactory
  InetAddressFactory is used to obtain InetAddress from host.
  org.apache.hadoop.util.MergeSort
  An implementation of the core algorithm of MergeSort.
  org.apache.hadoop.util.NativeCodeLoader
  A helper to load the native hadoop code i.e. libhadoop.so.
  org.apache.hadoop.util.NativeLibraryChecker
  OperationDuration
  Little duration counter.
  org.apache.hadoop.util.Options
  This class allows generic access to variable length type-safe parameter lists.
  org.apache.hadoop.util.Options.BooleanOption
  org.apache.hadoop.util.Options.ClassOption
  org.apache.hadoop.util.Options.FSDataInputStreamOption
  org.apache.hadoop.util.Options.FSDataOutputStreamOption
  org.apache.hadoop.util.Options.IntegerOption
  org.apache.hadoop.util.Options.LongOption
  org.apache.hadoop.util.Options.PathOption
  org.apache.hadoop.util.Options.ProgressableOption
  org.apache.hadoop.util.Options.StringOption
  org.apache.hadoop.util.PerformanceAdvisory
  org.apache.hadoop.util.PlatformName
  A helper class for getting build-info of the java-vm.
  org.apache.hadoop.util.Preconditions
  This class replaces `guava.Preconditions` which provides helpers to validate the following conditions: An invalid `null` obj causes a `NullPointerException`. An invalid argument causes an `IllegalArgumentException`. An invalid state causes an `IllegalStateException`. An invalid index causes an `IndexOutOfBoundsException`.
  org.apache.hadoop.util.PrintJarMainClass
  A micro-application that prints the main class name out of a jar file.
  org.apache.hadoop.util.PriorityQueue<T>
  A PriorityQueue maintains a partial ordering of its elements such that the least element can always be found in constant time.
  org.apache.hadoop.util.ProcessUtils
  Process related utilities.
  org.apache.hadoop.util.ProgramDriver
  A driver that is used to run programs added to it
  org.apache.hadoop.util.Progress
  Utility to assist with generation of progress reports.
  Progressable
  A facility for reporting progress.
  org.apache.hadoop.util.ProtoUtil
  PureJavaCrc32
  A pure-java implementation of the CRC32 checksum that uses the same polynomial as the built-in native CRC32.
  PureJavaCrc32C
  A pure-java implementation of the CRC32 checksum that uses the CRC32-C polynomial, the same polynomial used by iSCSI and implemented on many Intel chipsets supporting SSE4.2.
  org.apache.hadoop.util.QuickSort
  An implementation of the core algorithm of QuickSort.
  org.apache.hadoop.util.RateLimiting
  Minimal subset of google rate limiter class.
  org.apache.hadoop.util.RateLimitingFactory
  Factory for Rate Limiting.
  org.apache.hadoop.util.ReadWriteDiskValidator
  ReadWriteDiskValidator is the class to check a directory by to create a file, write some bytes into it, read back, and verify if they are identical.
  org.apache.hadoop.util.ReadWriteDiskValidatorMetrics
  The metrics for a directory generated by `ReadWriteDiskValidator`.
  ReflectionUtils
  General reflection utils
  org.apache.hadoop.util.RunJar
  Run a Hadoop job jar.
  org.apache.hadoop.util.SemaphoredDelegatingExecutor
  This ExecutorService blocks the submission of new tasks when its queue is already full by using a semaphore.
  org.apache.hadoop.util.SequentialNumber
  Sequential number generator.
  org.apache.hadoop.util.ServicePlugin
  Service plug-in interface.
  org.apache.hadoop.util.ServletUtil
  org.apache.hadoop.util.Sets
  Static utility methods pertaining to `Set` instances.
  Shell
  A base class for running a Shell command.
  org.apache.hadoop.util.Shell.CommandExecutor
  org.apache.hadoop.util.Shell.ExitCodeException
  This is an IOException with exit code added.
  Shell.OSType
  org.apache.hadoop.util.Shell.ShellCommandExecutor
  A simple shell command executor.
  ShutdownHookManager
  The `ShutdownHookManager` enables running shutdownHook in a deterministic order, higher priority first.
  org.apache.hadoop.util.ShutdownThreadsHelper
  Helper class to shutdown `Thread`s and `ExecutorService`s.
  org.apache.hadoop.util.SignalLogger
  This class logs a message whenever we're about to exit on a UNIX signal.
  org.apache.hadoop.util.SignalUtil
  org.apache.hadoop.util.SignalUtil.Handler
  org.apache.hadoop.util.SignalUtil.Signal
  org.apache.hadoop.util.StopWatch
  A simplified StopWatch implementation which can measure times in nanoseconds.
  StringInterner
  Provides string interning utility methods.
  org.apache.hadoop.util.StringUtils
  General string utils
  StringUtils.TraditionalBinaryPrefix
  The traditional binary prefixes, kilo, mega, ..., exa, which can be represented by a 64-bit integer.
  SysInfo
  Plugin to calculate resource information on the system.
  org.apache.hadoop.util.SysInfoLinux
  Plugin to calculate resource information on Linux systems.
  org.apache.hadoop.util.SysInfoWindows
  Plugin to calculate resource information on Windows systems.
  org.apache.hadoop.util.ThreadUtil
  org.apache.hadoop.util.Time
  Utility methods for getting the time and computing intervals.
  org.apache.hadoop.util.Timer
  Utility methods for getting the time and computing intervals.
  Tool
  A tool interface that supports handling of generic command-line options.
  ToolRunner
  A utility to help run `Tool`s.
  org.apache.hadoop.util.UTF8ByteArrayUtils
  VersionInfo
  This class returns build information about Hadoop components.
  org.apache.hadoop.util.VersionUtil
  A wrapper class to maven's ComparableVersion class, to comply with maven's version name string convention
  org.apache.hadoop.util.Waitable<T>
  Represents an object that you can wait for.
  org.apache.hadoop.util.WeakReferenceMap<K,V>
  A map of keys type K to objects of type V which uses weak references, so does lot leak memory through long-lived references at the expense of losing references when GC takes place..
  org.apache.hadoop.util.XMLUtils
  General xml utilities.
  org.apache.hadoop.util.ZKUtil
  Utilities for working with ZooKeeper.
  org.apache.hadoop.util.ZKUtil.BadAclFormatException
  org.apache.hadoop.util.ZKUtil.BadAuthFormatException
  org.apache.hadoop.util.ZKUtil.ZKAuthInfo
  An authentication token passed to ZooKeeper.addAuthInfo