org.apache.giraph.ooc

Class OutOfCoreIOStatistics

java.lang.Object

org.apache.giraph.ooc.OutOfCoreIOStatistics

public class OutOfCoreIOStatistics
extends Object

Class to collect statistics regarding IO operations done in out-of-core mechanism.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	OutOfCoreIOStatistics.BytesDuration Helper class to return results of statistics collector for a certain command type

Field Summary

Fields

Modifier and Type	Field and Description
static IntConfOption	DISK_BANDWIDTH_ESTIMATE An estimate of disk bandwidth.
static IntConfOption	IO_COMMAND_HISTORY_SIZE How many recent IO operations should we keep track of? Any report given out of this statistics collector is only based on most recent IO operations.
static IntConfOption	STATS_PRINT_FREQUENCY Use this option to control how frequently to print OOC statistics.

Constructor Summary

Constructors

Constructor and Description
OutOfCoreIOStatistics(ImmutableClassesGiraphConfiguration conf, int numIOThreads) Constructor

Method Summary

Modifier and Type	Method and Description
OutOfCoreIOStatistics.BytesDuration	getCommandTypeStats(IOCommand.IOCommandType type) Get aggregate statistics of a given command type in the command history
long	getDiskBandwidth()
String	toString()
void	update(IOCommand.IOCommandType type, long bytesTransferred, long duration) Update statistics with the last IO command that is executed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DISK_BANDWIDTH_ESTIMATE

public static final IntConfOption DISK_BANDWIDTH_ESTIMATE

An estimate of disk bandwidth. This number is only used just at the start of the computation, and will be updated/replaced later on once a few disk operations happen.

IO_COMMAND_HISTORY_SIZE

public static final IntConfOption IO_COMMAND_HISTORY_SIZE

How many recent IO operations should we keep track of? Any report given out of this statistics collector is only based on most recent IO operations.

STATS_PRINT_FREQUENCY

public static final IntConfOption STATS_PRINT_FREQUENCY

Use this option to control how frequently to print OOC statistics.

Constructor Detail

OutOfCoreIOStatistics

public OutOfCoreIOStatistics(ImmutableClassesGiraphConfiguration conf,
                             int numIOThreads)

Constructor

Parameters:

conf - configuration

numIOThreads - number of disks/IO threads

Method Detail

update

public void update(IOCommand.IOCommandType type,
                   long bytesTransferred,
                   long duration)

Update statistics with the last IO command that is executed.

Parameters:

type - type of the IO command that is executed

bytesTransferred - number of bytes transferred in the last IO command

duration - duration it took for the last IO command to complete (milliseconds)

toString

public String toString()

Overrides:

toString in class Object

getDiskBandwidth

public long getDiskBandwidth()

Returns:

most recent estimate of the disk bandwidth

getCommandTypeStats

public OutOfCoreIOStatistics.BytesDuration getCommandTypeStats(IOCommand.IOCommandType type)

Get aggregate statistics of a given command type in the command history

Parameters:

type - type of the command to get the statistics for

Returns:

aggregate statistics for the given command type